Fuel Storage Tanks
Remade from scratch to the authoring rules: defaults asserted only where four of five projects would choose them, and scope boundaries matched to the neighboring standards
Showing changes from Rev 2
to Rev 3
in Fuel Storage Tanks.
---
title: Fuel Storage Tanks
category: Mechanical / Piping & Pumps
−toc_depth: 3
description: >
− When to use: Factory-fabricated liquid fuel storage tanks — the vessel, its
− integral secondary containment, and immediately connected appurtenances — for
− emergency generator plants, fuel-oil boiler plants, fleet fueling, industrial
− and process facilities, and data centers. Covers aboveground tanks (UL 142,
− UL 2080, UL 2085), underground tanks (UL 58 steel, UL 1316 fiberglass),
− packaged-generator sub-base/belly tanks, and day/auxiliary tanks, including
− containment, overfill prevention, venting, leak detection, cathodic protection,
− anchorage, gauging, and vessel testing. Scope ends at the tank nozzle
− connections.
− Not intended for: Fuel-oil transfer pumps, supply/return piping, polishing, and
− system controls (use [[sync/fuel-oil-systems]]); fuel gas and LP/propane interior
− piping (use [[sync/fuel-gas-piping]]); generator engine/alternator/controls (use
− [[sync/generators]]); emergency-power runtime and transfer design (use
− [[sync/generators]]); gasoline or aviation retail dispensing stations; bulk
− propane yard siting per NFPA 58; and oil/water separators, process chemical, or
− water storage tanks (API/AWWA fabrication paths, no SynC standard).
+ When to use: Factory-built fuel storage tanks furnished as vessels for stationary fuel-burning equipment on commercial, institutional, industrial, data center, and utility projects: the aboveground diesel and fuel-oil tank listed to UL 142, UL 2080, UL 2085, UL 80, or UL 2258, the underground tank listed to UL 58 with UL 1746 corrosion protection or to UL 1316, the tank set in a below-grade vault listed to UL 2245, the generator sub-base tank as a vessel, the day tank as a vessel, and the ASME liquefied-petroleum-gas container that stores propane for an engine-generator, a boiler, or other on-site equipment under NFPA 58. Covers the listing and construction, the secondary containment, the overfill prevention and spill containment at the fill, the normal and emergency vent devices, the leak detection sensors, the level gauging, the corrosion protection, the anchorage and flotation restraint, the foundation interface, factory and field tightness testing, delivery, warranty, and spare parts. The scope ends at the tank nozzles and, for a propane container, at the outlet of the container service valve.
+
+ Not intended for: The fuel-oil pumps, the fill, supply, return, and vent piping beyond the tank nozzles, fuel polishing, tank heating, day-tank level logic, and the fuel-oil monitoring console where one is furnished with the system ([[sync/fuel-oil-systems]]); the first-stage regulator at a propane container and the gas piping from the container to the appliance ([[sync/fuel-gas-piping]]); the engine, the alternator and its excitation, the governor, the exhaust, the enclosure, and the starting batteries of an engine-generator ([[sync/generators]]); the burner and the oil train of a boiler ([[sync/boilers]]); the runtime class and the alternate-source capacity of an emergency power system ([[sync/emergency-and-standby-power]]); motor-vehicle dispensing stations, aviation and marine fueling, and the Class I liquid tanks that serve them under NFPA 30A; field-erected tanks built to API 650 or API 620; oil-water separators, chemical storage tanks, and water storage tanks; the concrete pad as a structure ([[sync/concrete-pads]]); anchor rod grades and setting ([[sync/structural-steel-anchor-bolts]], [[sync/post-installed-anchors]]); excavation, groundwater control during construction, and backfill above the tank excavation ([[sync/earthwork]], [[sync/excavation-support-and-dewatering]]); the site grading that keeps a release out of a storm inlet ([[sync/site-rough-grading]]); the spill-control shutoff at the outlet of a stormwater facility ([[sync/stormwater-management-systems]]); the grounding electrode system ([[sync/grounding-and-bonding]]); the bollards that protect a tank from vehicles ([[sync/site-furnishings-and-bollards]]); and the raceway and cable that carry the tank's alarm and gauge signals ([[sync/raceways-and-conduit]], [[sync/conductors-and-cables]]).
---
# Scope {toc}
−## This standard governs the procurement, fabrication, and installation of factory-built liquid fuel storage tanks and their integral appurtenances. {note}
+## This standard covers the fuel storage tank as a vessel, from the shell and its secondary containment to the appurtenances mounted on the tank itself: the fill connection with its spill container and overfill prevention device, the normal and emergency vent devices at the tank openings, the leak detection sensors in the interstitial space or the containment, the level gauge and its alarm contacts, the manway and the nozzles, the saddles, skid, or legs, the corrosion protection, and the anchorage to the foundation or the flotation restraint in the excavation. {note}
−## The vessel, its integral secondary containment, overfill prevention, venting, leak detection, gauging, anchorage, cathodic protection (underground), and vessel pressure/leak testing are covered. The scope ends at the tank nozzle connections. {note}
+## A tank belongs to this standard in any of four roles: a bulk storage tank remote from the equipment it serves, a sub-base tank built into the base of a packaged engine-generator, a day tank at the equipment, or an ASME container storing propane for on-site equipment. The role decides which articles apply and what the capacity follows from, so the role is the first selection on the datasheet. {note}
−## Aboveground storage tanks (ASTs) listed to UL 142, UL 2080, or UL 2085, underground storage tanks (USTs) listed to UL 58 or UL 1316, sub-base (belly) tanks integral to packaged generator sets, and day/auxiliary tanks are included. {note}
+## The boundary with the fuel-oil system is the face of the tank nozzle. Everything that connects to a nozzle and carries fuel, vapor, or a signal away from the tank, including the fill piping to a remote fill station, the vent piping to its termination, the supply and return piping, the pumps and their controls, fuel polishing, tank heating, and the fuel-oil monitoring console, is furnished under [[sync/fuel-oil-systems]]. For a propane container the boundary is the outlet of the container service valve, and the first-stage regulator mounted there begins the system furnished under [[sync/fuel-gas-piping]]. {note}
−## Applicable project types are new construction and tank-replacement work for emergency generator plants, fuel-oil boiler plants, fleet fueling, industrial and process facilities, and data centers. {note}
+## The following are governed elsewhere and are outside this standard. {note}
−## Fuel-oil transfer pumps, supply and return piping, fuel polishing systems, and system-level controls are covered by [[sync/fuel-oil-systems]], which owns the complete fuel-oil system from the tank fill connection to the prime mover. {note}
+- The engine, the alternator and its excitation, the governor and voltage regulator, the exhaust silencer, the enclosure, and the starting batteries of the engine-generator ([[sync/generators]])
+- The burner, the oil train downstream of the appliance shutoff valve, and the venting of a boiler ([[sync/boilers]])
+- The class and runtime of an emergency or standby power system and the capacity its alternate source carries ([[sync/emergency-and-standby-power]])
+- Motor-vehicle dispensing stations, aviation and marine fueling, and the Class I liquid tanks that serve them under NFPA 30A
+- Field-erected tanks built to API 650 or API 620, oil-water separators, chemical storage tanks, and water storage tanks
+- The concrete pad or foundation as a structure ([[sync/concrete-pads]], [[sync/shallow-foundations]]), the anchor rods cast into it ([[sync/structural-steel-anchor-bolts]]), and the anchors drilled into it ([[sync/post-installed-anchors]])
+- Excavation for an underground tank, worker protection, construction groundwater control, and backfill above the tank excavation ([[sync/earthwork]], [[sync/excavation-support-and-dewatering]])
+- Grading and drainage of the tank area so that a release is held away from storm inlets ([[sync/site-rough-grading]]), and the spill-control shutoff at the outlet of a stormwater facility ([[sync/stormwater-management-systems]])
+- The grounding electrode system and the bonding of the tank and its piping ([[sync/grounding-and-bonding]])
+- The bollards and barriers that protect an aboveground tank or container from vehicle impact ([[sync/site-furnishings-and-bollards]])
+- The raceway and cable that carry the leak, level, and alarm signals from the tank ([[sync/raceways-and-conduit]], [[sync/conductors-and-cables]])
+- The output signal type and the hazardous-location protection of a level transmitter or temperature element that reports to a plant monitoring system ([[sync/pressure-instrumentation]], [[sync/temperature-instrumentation]])
−## Generator engine, alternator, controls, and exhaust are covered by [[sync/generators]]; a sub-base tank factory-assembled as an integral part of a UL 2200-listed generator unit is selected under that standard, but the tank listing requirements of this standard still apply to it. {note}
+## The location of each tank, whether outdoors, inside a building, or below grade, shall be as indicated on [[drawing: the contract drawings]].
−## Natural gas and LP/propane interior distribution piping is covered by [[sync/fuel-gas-piping]]. Gasoline and aviation fuel retail dispensing stations, bulk propane siting per NFPA 58, and oil/water separator, process chemical, or water storage tanks are outside this scope. {note}
+## The Contractor shall coordinate the nozzle schedule, the fill point, the vent terminations, the signal destinations, and the anchorage of each tank with the standards named in this section before the tank is released for fabrication.
−## The Contractor shall coordinate the division of work between the tank vessel furnished under this standard and the fuel-system piping, pumps, and controls furnished under [[sync/fuel-oil-systems]] so that no interface item is left un-bid.
−
# Referenced Standards {toc}
## Equipment, materials, and installation shall comply with the latest adopted edition of each of the following unless a specific edition is cited.
−## Where referenced standards conflict, the more stringent requirement shall govern unless the Engineer of Record directs otherwise in writing.
+## Where the contract documents, the adopted codes, the Authority Having Jurisdiction, or two referenced standards impose conflicting requirements, the more stringent requirement shall govern unless the Engineer of Record directs otherwise in writing.
| Standard | Title |
|----------|-------|
| NFPA 30 | Flammable and Combustible Liquids Code |
−| NFPA 30A | Code for Motor Fuel Dispensing Facilities and Repair Garages |
−| NFPA 37 | Installation and Use of Stationary Combustion Engines and Gas Turbines |
−| NFPA 110 | Emergency and Standby Power Systems |
+| NFPA 31 | Standard for the Installation of Oil-Burning Equipment |
+| NFPA 37 | Standard for the Installation and Use of Stationary Combustion Engines and Gas Turbines |
+| NFPA 58 | Liquefied Petroleum Gas Code |
+| NFPA 70 | National Electrical Code (Articles 500 through 505, hazardous locations) |
+| NFPA 110 | Standard for Emergency and Standby Power Systems |
+| NFPA 704 | Standard System for the Identification of the Hazards of Materials for Emergency Response |
+| IFC | International Fire Code (Chapter 57 and Chapter 61) |
+| UL 58 | Steel Underground Tanks for Flammable and Combustible Liquids |
+| UL 80 | Steel Tanks for Oil-Burner Fuels and Other Combustible Liquids |
| UL 142 | Steel Aboveground Tanks for Flammable and Combustible Liquids |
+| UL 1316 | Fibre Reinforced Underground Tanks for Flammable and Combustible Liquids |
+| UL 1746 | External Corrosion Protection Systems for Steel Underground Storage Tanks |
| UL 2080 | Fire Resistant Tanks for Flammable and Combustible Liquids |
| UL 2085 | Protected Aboveground Tanks for Flammable and Combustible Liquids |
−| UL 58 | Steel Underground Tanks for Flammable and Combustible Liquids |
−| UL 1316 | Glass-Fiber-Reinforced Plastic Underground Storage Tanks for Petroleum Products |
−| UL 1746 | External Corrosion Protection Systems for Steel Underground Storage Tanks |
−| UL 2200 | Stationary Engine Generator Assemblies |
−| 40 CFR Part 280 | Technical Standards for Owners and Operators of Underground Storage Tanks |
−| 40 CFR Part 112 | Oil Pollution Prevention (SPCC Rule) |
−| IFC | International Fire Code (Chapter 57) |
+| UL 2245 | Below-Grade Vaults for Flammable Liquid Storage Tanks |
+| UL 2258 | Nonmetallic Tanks for Oil-Burner Fuels and Other Combustible Liquids |
+| UL 50E | Enclosures for Electrical Equipment, Environmental Considerations |
+| NEMA 250 | Enclosures for Electrical Equipment (1000 Volts Maximum) |
+| ASME BPVC Section VIII, Division 1 | Rules for Construction of Pressure Vessels |
| API Std 2000 | Venting Atmospheric and Low-Pressure Storage Tanks |
−| PEI RP200 | Installation of Aboveground Storage Systems for Motor Vehicle Fueling |
−| ASTM D975 | Standard Specification for Diesel Fuel Oils |
−| ASCE 7 | Minimum Design Loads and Associated Criteria for Buildings and Other Structures |
−| NACE SP0169 | Control of External Corrosion on Underground or Submerged Metallic Piping Systems |
+| PEI RP100 | Recommended Practices for Installation of Underground Liquid Storage Systems |
+| PEI RP200 | Recommended Practices for Installation of Aboveground Storage Systems for Motor Vehicle Fueling |
+| STI SP001 | Standard for the Inspection of Aboveground Storage Tanks |
+| STI R051 | Cathodic Protection Testing Procedures for sti-P3 USTs |
| NACE SP0285 | External Corrosion Control of Underground Storage Tank Systems by Cathodic Protection |
+| ASCE 7 | Minimum Design Loads and Associated Criteria for Buildings and Other Structures |
+| ASTM D975 | Standard Specification for Diesel Fuel Oils |
+| ASTM D396 | Standard Specification for Fuel Oils |
+| ASTM D7467 | Standard Specification for Diesel Fuel Oil, Biodiesel Blend (B6 to B20) |
+| ASTM D1835 | Standard Specification for Liquefied Petroleum (LP) Gases |
+| 40 CFR Part 280 | Technical Standards and Corrective Action Requirements for Owners and Operators of Underground Storage Tanks |
+| 40 CFR Part 112 | Oil Pollution Prevention |
# Submittals {toc}
## Action Submittals {toc}
−### The Contractor shall submit the following action submittals for review before fabrication:
−- Product data for the tank, including the UL listing standard, listing mark, and listing file number.
−- Shop drawings showing tank dimensions, nozzle schedule, lifting lugs, saddle or skid locations, and containment construction.
−- Capacity calculation showing nominal, usable, and required runtime volumes with the served equipment fuel consumption rate.
−- Secondary containment design showing interstitial space or dike volume against the 110% requirement.
−- Vent sizing calculation for normal and emergency venting per API 2000 and NFPA 30.
−- Anchorage and seismic restraint calculations, PE-stamped where required by ASCE 7.
−- Buoyancy calculation and holddown design for underground tanks.
−- Cathodic protection design for steel underground tanks.
−- Fuel-material compatibility statement for the specified fuel grade and biodiesel blend.
+### The Contractor shall submit the following for the Engineer's review and return before any tank is released for fabrication:
+- Product data for each tank, giving the listing standard and the listing file number, the shell and head material and thickness, the containment construction, the nominal and the usable capacity, the fill limit, the operating and the empty weight, and the published fuel compatibility
+- Shop drawings for each tank showing the dimensions, the nozzle schedule with each nozzle's size, service, and location, the manway, the lifting lugs, the saddles, skid, or legs, the anchor bolt pattern, and the location of every appurtenance on the tank
+- A capacity statement for each tank reconciling the nominal capacity to the capacity the served equipment standard derives or the drawings indicate, with the fill limit and the unusable volume subtracted
+- Normal and emergency vent sizing for the primary tank and for the interstitial space, stating the fill rate, the withdrawal rate, and the wetted area used
+- Anchorage calculations for each aboveground tank, giving the seismic and wind reactions at the anchors and the anchor size and embedment, sealed by a professional engineer where required under Anchorage and Flotation
+- A flotation calculation for each underground tank, giving the buoyant force of the empty tank at the seasonal high groundwater elevation and the anchorage or ballast that resists it
+- Product data for the overfill prevention device, the spill container, the vent devices, the leak detection sensors, the level gauge, and the alarm contacts, with the wiring interface of every electrical device
+- A statement of compatibility of the shell, the lining, the gaskets, and the sensor materials with the fuel selected on the datasheet
+- For a propane container, the ASME data report, the NFPA 58 siting plan showing the separation distances from the container to buildings, property lines, and sources of ignition, and the container valve schedule
+
```datasheet
−label: Action Submittals
+label: Required Action Submittals
type: checkbox
options:
− - Tank product data and UL listing
− - Shop drawings (dimensions, nozzles, lifting)
− - Capacity / runtime calculation
− - Secondary containment volume calculation
− - Vent sizing calculation (normal + emergency)
− - Anchorage / seismic calculations
− - Buoyancy / holddown design (USTs)
− - Cathodic protection design (steel USTs)
− - Fuel compatibility statement
+ - "Tank product data with listing and capacity"
+ - "Tank shop drawings with nozzle schedule"
+ - "Capacity statement against the derived capacity"
+ - "Normal and emergency vent sizing"
+ - "Anchorage calculations"
+ - "Flotation calculation for underground tanks"
+ - "Appurtenance product data with wiring interfaces"
+ - "Fuel compatibility statement"
+ - "Propane container data report, siting plan, and valve schedule"
default:
− - Tank product data and UL listing
− - Shop drawings (dimensions, nozzles, lifting)
− - Capacity / runtime calculation
− - Secondary containment volume calculation
− - Vent sizing calculation (normal + emergency)
− - Anchorage / seismic calculations
+ - "Tank product data with listing and capacity"
+ - "Tank shop drawings with nozzle schedule"
+ - "Capacity statement against the derived capacity"
+ - "Normal and emergency vent sizing"
+ - "Anchorage calculations"
+ - "Appurtenance product data with wiring interfaces"
+ - "Fuel compatibility statement"
```
+### A tank shall not be released for fabrication until its shop drawings have been reviewed and returned without exception, and a tank fabricated before that return shall be modified or replaced at the Contractor's expense where the review requires a change.
+
## Informational Submittals {toc}
−### The Contractor shall submit the following informational submittals:
−- Manufacturer factory pressure-test certificate for the vessel.
−- Mill certificates for tank steel or resin certifications for fiberglass tanks.
−- Welder qualifications and welding procedure specifications.
−- Interstitial monitoring sensor product data and wiring interface documentation.
+### The Contractor shall submit the following for information before the tank is delivered to the site:
+- The manufacturer's factory tightness test certificate for each tank, stating the test pressure, the duration, and the result for the primary tank and for the interstitial space
+- Mill certificates for the steel of a steel tank, or the resin and glass certifications for a fiberglass tank
+- Welder qualifications and the welding procedure specifications for a steel tank
+- The manufacturer's installation instructions for each tank, including the bedding and backfill requirements of an underground tank and the lifting instructions of every tank
+- The manufacturer's warranty terms and the installation conditions the warranty requires
+- For a steel underground tank with sacrificial anodes, the anode design and the manufacturer's test station instructions
+
```datasheet
−label: Informational Submittals
+label: Required Informational Submittals
type: checkbox
options:
− - Factory pressure-test certificate
− - Mill / resin certifications
− - Welder qualifications and WPS
− - Leak-detection sensor data and wiring interface
+ - "Factory tightness test certificates"
+ - "Mill or resin certifications"
+ - "Welder qualifications and welding procedures"
+ - "Installation instructions"
+ - "Warranty terms and installation conditions"
+ - "Sacrificial anode design and test station instructions"
default:
− - Factory pressure-test certificate
− - Mill / resin certifications
− - Leak-detection sensor data and wiring interface
+ - "Factory tightness test certificates"
+ - "Mill or resin certifications"
+ - "Installation instructions"
+ - "Warranty terms and installation conditions"
```
## Closeout Submittals {toc}
−### The Contractor shall submit the following closeout submittals:
−- Field acceptance test reports for the vessel and secondary containment.
−- State UST registration confirmation, where applicable.
−- SPCC Plan documentation or confirmation that the site is below threshold.
−- Operation and maintenance manuals, including fuel-management and microbial-control guidance.
−- Cathodic protection commissioning report with potential readings.
+### The Contractor shall submit the following before the tank is accepted:
+- Field tightness test reports for the primary tank and for the interstitial space, with the test method, the pressure or vacuum, the duration, and the result
+- The leak detection, overfill alarm, and level alarm functional test record, showing each sensor and contact exercised and the alarm received where the datasheet sends it
+- The cathodic protection commissioning record for a steel underground tank, with the structure-to-soil potentials and the test station location
+- The state registration or notification for an underground tank, where the state program requires one, and the installer certification the state program requires
+- The Spill Prevention, Control, and Countermeasure determination for the site, stating the aggregate oil storage and whether a plan is required
+- Operation and maintenance data for the tank and its appurtenances, including the inspection schedule under STI SP001 for an aboveground tank, the release detection and spill container testing schedule under 40 CFR Part 280 for an underground tank, and the part numbers of every sensor, gasket, and vent device
+- Warranty documentation
+
```datasheet
−label: Closeout Submittals
+label: Required Closeout Submittals
type: checkbox
options:
− - Field acceptance test reports
− - State UST registration confirmation
− - SPCC Plan documentation / below-threshold confirmation
− - Operation and maintenance manuals
− - Cathodic protection commissioning report
+ - "Field tightness test reports"
+ - "Leak, overfill, and level alarm functional test record"
+ - "Cathodic protection commissioning record"
+ - "State underground tank registration and installer certification"
+ - "SPCC determination"
+ - "Operation and maintenance data with inspection schedules"
+ - "Warranty documentation"
default:
− - Field acceptance test reports
− - Operation and maintenance manuals
+ - "Field tightness test reports"
+ - "Leak, overfill, and level alarm functional test record"
+ - "SPCC determination"
+ - "Operation and maintenance data with inspection schedules"
+ - "Warranty documentation"
```
# Quality Assurance {toc}
−## The tank shall bear the listing mark of a Nationally Recognized Testing Laboratory for the applicable UL standard. {note}
+## Listing and Manufacturer Qualifications {toc}
−## A listing mark is the AHJ's primary evidence that the tank meets the construction, containment, and where applicable fire-rating requirements of the adopted code; an unlisted vessel cannot be permitted for combustible-liquid service. {note}
+### Each liquid fuel tank shall bear the listing mark of a Nationally Recognized Testing Laboratory for the listing standard selected under this standard, and each propane container shall bear the ASME Code symbol stamp and the nameplate NFPA 58 requires.
−## The tank manufacturer shall be a firm regularly engaged in the fabrication of listed fuel storage tanks of the type and capacity specified.
+### The listing mark is the evidence the Authority Having Jurisdiction accepts that the tank's steel thickness, weld design, containment, and venting openings meet the construction rules of the adopted fire code, and an unlisted shop-built tank cannot be permitted for combustible liquid service without an engineering evaluation the code does not otherwise require. {note}
−## Welding of steel tanks shall be performed by welders qualified under a written welding procedure specification.
+### The tank manufacturer shall have fabricated listed tanks of the selected listing standard and of the specified capacity for not less than five years.
−## The selected UL listing standard shall be confirmed with the Authority Having Jurisdiction before procurement. {note}
+### Welding of a steel tank shall be performed by welders qualified to the procedure specifications submitted under this standard.
−## UL 142 is adequate for many exterior ASTs, but local fire codes and occupancy type may mandate the 2-hour fire-rated UL 2085; confirming the requirement with the AHJ before purchase avoids costly field re-specification of an already-fabricated tank. {note}
+### Where a listing standard other than the one selected on the datasheet is required by the Authority Having Jurisdiction for the tank's location, the Contractor shall report the requirement to the Engineer in writing before fabrication, and the Engineer shall direct the selection.
−# Regulatory and Environmental Compliance {toc}
+## Regulatory Determinations {toc}
−## The aggregate aboveground and underground oil storage volume on the site shall be summed across all oil-containing vessels, including generator sub-base tanks, to determine SPCC and registration applicability.
+### The Contractor shall sum the capacity of every oil-storing tank on the site, including each generator sub-base tank and each day tank, and shall report the aggregate aboveground and the aggregate underground oil storage to the Owner in the SPCC determination.
−## The Spill Prevention, Control, and Countermeasure (SPCC) Rule applies when aggregate aboveground oil storage exceeds 1,320 gallons or aggregate underground oil storage exceeds 42,000 gallons. A frequent omission is failing to count multiple generator sub-base tanks, which together commonly exceed the aboveground threshold on a multi-generator plant. {note}
+### The oil pollution prevention rule in 40 CFR Part 112 applies to a facility whose aggregate aboveground oil storage exceeds 1,320 gallons, counting every container of 55 gallons or more, or whose aggregate underground storage exceeds 42,000 gallons. The threshold is a site total, so a plant of three generators with 500-gallon sub-base tanks crosses it with no single tank that looks large, and the plan that follows is the Owner's obligation before the tanks are filled. {note}
−## A facility that meets the SPCC threshold shall have an SPCC Plan prepared and certified before the tanks are placed in service.
+### Where an underground tank is regulated under 40 CFR Part 280 or the state program that implements it, the Contractor shall file the notification or registration the program requires before the tank is backfilled, and shall employ an installer certified as the state program requires.
−## State UST registration shall be obtained before any underground tank is backfilled.
+### The federal underground tank rule exempts a tank storing heating oil for consumptive use on the premises, and until 2018 it exempted an emergency generator tank from release detection; many states regulate both, and a state program is often stricter than the federal rule it implements. A tank backfilled before its registration is accepted has in some jurisdictions been ordered excavated, so the registration is a precondition to burial rather than a closeout item. {note}
−## State UST programs authorized under RCRA Subtitle I require registration prior to burial; backfilling before the permit is issued can force mandatory excavation in some jurisdictions. {note}
+### Where a tank is installed inside a building, the Contractor shall confirm that the tank's capacity, its listing, and the construction of the room satisfy NFPA 30 Chapter 24, NFPA 37 where the tank serves an engine, and NFPA 31 where it serves a burner, and shall report any conflict with the datasheet selection to the Engineer before fabrication.
−## Underground tanks installed or replaced after April 11, 2016 shall provide secondary containment with interstitial monitoring per 40 CFR 280.
+## Identification {toc}
−## Carrying forward a pre-2016 single-wall UST specification on a replacement project is a common error; the federal rule now requires double-wall construction with interstitial monitoring for new and replacement underground tanks. {note}
+### Each tank shall be marked on the shell, in letters legible from the fill point, with the fuel stored, the nominal capacity in gallons, and the hazard identification NFPA 704 requires in the form the adopted fire code prescribes.
−# Tank Selection and Configuration {toc}
+### Each fill connection shall carry a permanent tag naming the fuel and the tank it fills, and where more than one tank is filled from one location, the tags shall also carry the tank designation shown on the shop drawings.
−## Location and Listing {toc}
+### A delivery driver who cannot tell a diesel fill from a heating oil fill, or one tank's fill from another's, is how the wrong tank gets the product, and the tag at the fill is read in the dark from a hose reel. {note}
−### Aboveground tanks (ASTs) avoid excavation, buoyancy, and corrosion concerns and simplify leak detection and inspection, but consume site area and are subject to fire-code setbacks. Underground tanks (USTs) free the site surface and reduce fire exposure but add excavation, buoyancy, corrosion, and registration obligations. The choice is driven by available area, setbacks, soil and water-table conditions, and zoning or visual constraints. {note}
+# Tank Service and Configuration {toc}
−### Whether the fuel storage tank is aboveground or underground shall be specified based on available site area, setbacks, soil, water-table conditions, and zoning constraints.
+## Stored Fuel {toc}
+### The fuel each liquid fuel tank stores shall be as indicated in the datasheet.
+
```datasheet
−label: Tank Location
+label: Stored Fuel
+type: select
+options:
+ - "No. 2 ultra-low-sulfur diesel to ASTM D975"
+ - "Biodiesel blend B6 to B20 to ASTM D7467"
+ - "No. 2 heating fuel oil to ASTM D396"
+ - "No. 1 diesel or kerosene to ASTM D975 or ASTM D396"
+ - "Winter-blended No. 1 and No. 2 diesel to ASTM D975"
+default: "No. 2 ultra-low-sulfur diesel to ASTM D975"
+```
+
+### No. 2 ultra-low-sulfur diesel is the fuel the engine manufacturers rate their stationary sets on and the fuel the road supply chain delivers, which is why it is the default; a biodiesel blend is the fuel where a procurement policy or a state blending mandate supplies it, and blends above B5 attack nitrile elastomers and some interior coatings and hold more water, so the blend has to be declared for the manufacturer to select compatible gaskets and a lining; No. 2 heating oil is the fuel of an oil-fired boiler and is exempt from the federal underground tank rule when burned on the premises; No. 1 oil and kerosene gel at a lower temperature at a higher price per gallon and a lower energy content; a winter blend buys cold-flow margin for a tank in an unheated outdoor location without going to straight No. 1. {note}
+
+### The shell, the interior lining where one is selected, the gaskets, the sensor bodies, and the float materials shall be rated by their manufacturers for the fuel selected, including the biodiesel content of a blend.
+
+### A tank storing a biodiesel blend shall be furnished with a water draw-off at the low point of the shell, and the operation and maintenance data shall state the bottom-water draining interval the fuel supplier recommends.
+
+## Tank Role {toc}
+
+### The role each tank serves shall be as indicated in the datasheet.
+
+```datasheet
+label: Tank Role
type: radio
options:
− - Aboveground (AST)
− - Underground (UST)
−default: Aboveground (AST)
+ - "Bulk storage tank remote from the served equipment"
+ - "Generator sub-base tank"
+ - "Day tank at the served equipment"
```
−### The fire-protection listing class is driven by the IFC occupancy, AHJ requirements, and the tank's proximity to occupied structures or high-exposure locations. UL 142 is the standard steel AST; UL 2080 adds a fire-resistant rating; UL 2085 adds a full 2-hour fire endurance plus vehicle-impact resistance and is often required where a tank is in or near an occupied building. {note}
+### A bulk tank holds the site's fuel where the site can hold it and feeds the equipment through the pumps and piping of the fuel-oil system, so it can be as large as the runtime demands and is the one role a buried tank serves; a sub-base tank is bought with the generator as part of its UL 2200 assembly, carries the set's weight, and holds what the base can hold, which fixes the runtime at the set unless a bulk tank makes it up; a day tank at the equipment holds a few hours of fuel at the head and pressure the engine or burner needs and is filled from a bulk tank, so its capacity follows from the fuel-oil system's controls rather than from the runtime. The role follows the fuel storage arrangement of the served equipment, so no role is the norm across projects. {note}
−### The fire-protection listing standard for the aboveground storage tank shall be specified based on occupancy, AHJ requirements, and proximity to occupied structures.
+### Where the tank serves an engine-generator, its role shall agree with the diesel fuel storage arrangement selected under [[sync/generators]], and the Contractor shall report any disagreement to the Engineer before fabrication.
+### A generator sub-base tank shall be furnished by the generator manufacturer as part of the UL 2200 assembly as [[sync/generators]] requires, and the construction, containment, venting, overfill prevention, and leak detection selected under this standard shall be furnished on it.
+
+### A generator sub-base tank shall additionally carry the fuel level sender, the low-fuel contact, and the shutoff valve at the supply outlet that [[sync/generators]] requires of it, wired as that standard directs.
+
+### A day tank inside an engine room shall not exceed the capacity NFPA 37 permits at its location, and a day tank serving a burner shall not exceed the capacity NFPA 31 permits at its location.
+
+## Tank Placement {toc}
+
+### Each tank shall be placed aboveground, underground, or within a below-grade vault as indicated in the datasheet.
+
```datasheet
−label: AST Listing Standard
+label: Tank Placement
type: radio
options:
− - UL 142 (standard steel AST)
− - UL 2080 (fire-resistant)
− - UL 2085 (protected, 2-hour fire-rated)
−default: UL 142 (standard steel AST)
+ - "Aboveground"
+ - "Underground"
+ - "Aboveground tank within a below-grade vault"
+default: "Aboveground"
```
−### Underground tank material is steel (UL 58, most common) or fiberglass-reinforced plastic (UL 1316). Fiberglass is corrosion-immune and preferred in corrosive or high-moisture soils; steel requires external corrosion protection per UL 1746. {note}
+### An aboveground tank is inspected by walking around it, its leak goes where it can be seen, and its listing, containment, and registration burden are the lightest, at the cost of the site area the fire code setbacks consume and a shell exposed to weather and vehicles; an underground tank gives the site surface back and takes the tank out of the fire exposure, at the cost of excavation, flotation restraint, corrosion protection, the federal and state release detection program, and the registration that precedes burial; a tank in a below-grade vault listed to UL 2245 stays an aboveground tank in the eyes of the code while sitting below grade, and is the arrangement for a site that can give up neither its surface nor the inspectability of an aboveground tank. Aboveground placement is the default because it is what most new fuel-oil installations now choose. {note}
−### The underground storage tank material and listing standard shall be specified based on the corrosivity and moisture condition of the surrounding soil.
+### A tank within a below-grade vault shall be a tank listed for aboveground service set in a vault listed to UL 2245, with the vault's drainage, ventilation, and access as NFPA 30 requires of a vaulted tank.
+## Nominal Capacity {toc}
+
+### The nominal capacity of each tank shall be as indicated in the datasheet.
+
```datasheet
−label: UST Material and Listing
+label: Nominal Tank Capacity
+type: range
+unit: gal
+derived: "the runtime or delivery interval established under the served equipment standard or indicated on the drawings, the full-load fuel consumption of the served equipment, and the fill limit and unusable volume the tank listing and its overfill prevention device impose"
+min: 25
+max: 60000
+step: 5
+default: derived
+```
+
+### Nominal capacity is the volume of the shell. The overfill prevention device stops the fill at or below 95 percent of it, and the suction nozzle leaves a dead volume at the bottom that the engine never draws, so the usable volume is about 85 to 90 percent of the nominal and the runtime calculation is done on the usable volume. The capacity is not a decision made at the tank: for a generator it follows from the runtime class the emergency power system assigns and the fuel the set burns at full load, and for a burner it follows from the delivery interval the Owner can live with and the firing rate, so the field points at that basis rather than carrying a number of its own. {note}
+
+### Where the tank is a generator sub-base tank or a day tank serving an engine-generator, its usable capacity shall be the usable fuel capacity at the set derived under [[sync/generators]].
+
+### Where the tank is a bulk storage tank, the Contractor shall state on the capacity statement the fuel consumption figure used and the document it came from.
+
+## Tank Form {toc}
+
+### Each tank shall be of the form indicated in the datasheet.
+
+```datasheet
+label: Tank Form
type: radio
options:
− - Steel (UL 58 with UL 1746 corrosion protection)
− - Fiberglass / FRP (UL 1316)
−default: Steel (UL 58 with UL 1746 corrosion protection)
+ - "Horizontal cylindrical"
+ - "Vertical cylindrical"
+ - "Rectangular"
```
−## Orientation and Construction {toc}
+### A horizontal cylinder is the lowest-cost form per gallon above a few hundred gallons, puts its weight on two saddles, and is the form of nearly every underground tank; a vertical cylinder holds the same volume in the smallest footprint and raises the suction and the gauge, at the cost of a taller fill and a higher center of gravity to anchor; a rectangular tank fits under a generator base, against a wall, or inside a room where a cylinder wastes the corners, and is the form of the sub-base tank, the day tank, and the small oil-burner tank. The form follows the role and the space, so no form is the norm across the standard. {note}
−### Horizontal cylindrical is the most common form for facility ASTs and USTs; vertical cylindrical is selected where footprint is constrained; rectangular construction is typical of sub-base and day tanks built onto a generator base rail. {note}
+### Nozzle sizes, services, and locations on each tank shall be as indicated on [[drawing: the fuel system flow diagram]].
−### The tank orientation shall be specified based on the available site footprint and the tank's intended service.
+### Each tank shall be furnished with a bolted manway as indicated in the datasheet.
```datasheet
−label: Tank Orientation
+label: Bolted Manway
type: radio
options:
− - Horizontal cylindrical
− - Vertical cylindrical
− - Rectangular (sub-base / day tank)
−default: Horizontal cylindrical
+ - "Bolted manway not smaller than 18 in."
+ - "No manway, threaded inspection openings only"
```
−### Tank steel and wall thickness shall comply with the minimums of the applicable listing standard for the tank capacity.
+### A manway is how a tank that stores fuel for years is entered to remove the sludge and water that settle under a stored distillate, and how a damaged interior lining or a failed sensor is reached; it adds a flanged opening, a gasket, and a cover to a tank that otherwise has only threaded nozzles, and a tank of a few hundred gallons is cleaned through a 4 in. opening with a wand. {note}
−### UL 142 sets minimum steel wall thickness by capacity: 10 gauge (0.135 in) for tanks up to 1,200 gallons, 7 gauge (0.179 in) for 1,201 to 12,000 gallons, and 1/4 in for tanks over 12,000 gallons. UL 58 underground tanks have a minimum primary-wall thickness of 0.123 in and a minimum secondary-wall thickness of 0.093 in. {note}
+### Each tank shall be furnished with a threaded nozzle for a water draw-off or a stick-gauge opening that reaches the lowest point of the shell, in addition to the nozzles the flow diagram shows.
−### Where the tank serves an emergency or standby power system under NFPA 110, the fuel grade and quality shall be compatible with the served equipment.
+# Aboveground Tanks {toc}
+## Aboveground Tank Listing {toc}
+
+### Requirements in this article apply where the datasheet selects aboveground placement, including a tank within a below-grade vault.
+
+### An aboveground tank shall be listed to the standard indicated in the datasheet.
+
```datasheet
−label: Stored Fuel Grade
+label: Aboveground Tank Listing
type: radio
options:
− - No. 2 diesel (ULSD)
− - Biodiesel blend B5
− - Biodiesel blend B20
− - No. 2 fuel oil (heating)
−default: No. 2 diesel (ULSD)
+ - "UL 142 steel aboveground tank"
+ - "UL 2080 fire resistant tank"
+ - "UL 2085 protected tank"
+ - "UL 80 steel oil-burner fuel tank"
+ - "UL 2258 nonmetallic oil-burner fuel tank"
+default: "UL 142 steel aboveground tank"
```
−### Tank coatings, gaskets, and sealants shall be compatible with the specified fuel grade, including any biodiesel blend. {note}
+### UL 142 is the construction standard for the shop-built steel tank, and it is the listing of the sub-base tank, the day tank, and most bulk tanks, which is why it is the default; UL 2080 adds a two-hour fire test to a UL 142 tank and buys a reduction in the separation distances the fire code requires; UL 2085 adds to the fire test the insulation that limits the heat reaching the primary tank, a vehicle impact test, and a ballistics test, which is what the fire code and most Authorities Having Jurisdiction require where a tank sits close to a building, a property line, or a public way, at roughly twice the weight and a higher price than the same gallons in UL 142; UL 80 and UL 2258 are the listings of the steel and the polyethylene oil-burner tank of 660 gallons and less that sits in a basement or a utility room feeding a boiler or furnace, and neither is a listing for an engine fuel tank. {note}
−### Biodiesel blends of B20 and higher degrade nitrile rubber gaskets, seals, and some interior coatings used in steel tanks. When the project is in a biodiesel-supply region, B5 or B20 compatibility must be specified explicitly so the manufacturer selects compatible elastomers and linings. {note}
+### Where the separation distances NFPA 30 and the adopted fire code require for a UL 142 tank at its location cannot be met, the tank shall be listed to UL 2085 or shall be protected as the Authority Having Jurisdiction accepts in writing, whatever the datasheet selects.
−## Capacity and Runtime {toc}
+### The shell and head thickness of a steel aboveground tank shall be not less than the minimum the listing standard assigns for the tank's capacity, and the thickness shall be stated on the shop drawings.
−### The tank capacity shall be sized for the required runtime at the served equipment's full-load fuel consumption rate plus the planned delivery interval.
+## Aboveground Tank Support {toc}
−### NFPA 110 Level 1 requires a minimum of 8 hours of on-site fuel at 100% rated load; critical facilities such as hospitals and data centers commonly design for 24 to 96 hours. Only 80 to 85% of the rated tank volume is operationally usable once ullage for thermal expansion and the dead leg at the suction connection are subtracted. {note}
+### An aboveground tank shall be supported as indicated in the datasheet.
−### Specifying a tank to its nameplate runtime without subtracting the 15 to 20% unusable volume results in insufficient runtime. The runtime calculation shall be based on usable volume, not nameplate volume.
+```datasheet
+label: Aboveground Tank Support
+type: radio
+options:
+ - "Integral steel saddles"
+ - "Integral steel skid base"
+ - "Steel legs"
+ - "Flat bottom set directly on the foundation"
+```
+### Saddles carry a horizontal cylinder at two lines and lift the shell off the foundation where the bottom can be inspected and water cannot stand against it; a skid base ties the saddles into a frame that is lifted, set, and anchored as one piece and carries a stair or a pump cabinet, at the cost of steel; legs lift a small tank for gravity feed to a burner and are the support UL 80 and UL 2258 tanks ship with; a flat-bottom tank set directly on the foundation puts the whole bottom on concrete where it cannot be inspected, which is why the fire code and STI SP001 treat it as a different inspection category. {note}
+
+### Saddles, skids, and legs shall be welded to the shell by the tank manufacturer, and the shell at the support shall carry the reinforcing pad the listing requires.
+
+### A tank set on saddles or legs shall rest on a reinforced concrete pad constructed under [[sync/concrete-pads]] that extends not less than 6 in. beyond the supports on every side and stands not less than 4 in. above the finished surface, and a flat-bottom tank shall rest on a foundation constructed under [[sync/shallow-foundations]] or [[sync/concrete-pads]] that sheds water away from the bottom.
+
+## Aboveground Tank Exterior Coating {toc}
+
+### An aboveground steel tank shall be furnished with the shop-applied exterior coating system indicated in the datasheet.
+
```datasheet
−label: Nominal Tank Capacity
−type: range
−unit: gal
−min: 50
−max: 50000
−step: 50
+label: Aboveground Tank Exterior Coating
+type: select
+options:
+ - "Alkyd enamel over a rust-inhibitive primer"
+ - "Epoxy primer with an aliphatic polyurethane topcoat"
+ - "Powder coating over a blasted and primed surface"
+ - "Hot-dip galvanized shell with no topcoat"
+default: manufacturer
```
+### The manufacturer's standard coating is acceptable because the tank's listing does not depend on it and because every manufacturer finishes a tank to a system that holds up in an ordinary exterior exposure; an alkyd enamel is that standard system and chalks and fades in a few years of sun; an epoxy and polyurethane system holds its gloss and resists salt air and chemical fumes for a decade or more and is specified at a coastal or industrial site; powder coating gives a hard, uniform film on a tank small enough to fit the oven; a galvanized shell is the finish of some small outdoor burner tanks and takes no topcoat. {note}
+
+### The exterior topcoat color shall be the manufacturer's standard white or light reflective color unless another color is indicated on [[drawing: the mechanical equipment schedule]].
+
+### An aboveground steel tank shall be furnished with the interior surface indicated in the datasheet.
+
```datasheet
−label: Required Runtime at Full Load
−type: range
−unit: hr
−min: 8
−max: 96
−step: 4
−default: 24
+label: Aboveground Tank Interior Surface
+type: radio
+options:
+ - "Bare steel"
+ - "Fuel-compatible epoxy lining"
+default: "Bare steel"
```
−# Secondary Containment {toc}
+### Bare steel holds distillate fuel indefinitely and is the interior of nearly every diesel and heating oil tank, which is why it is the default; a lining is what a biodiesel blend above B5 or a fuel that will be polished and held for years calls for, because it keeps the water that settles in a stored fuel from pitting the bottom and keeps rust scale out of the fuel, at the cost of a lining that has to be rated for the blend. {note}
−## Double-wall (interstitial) containment is factory-built into the tank and is the default for new work, giving the smallest footprint and the cleanest interstitial-monitoring path. A single-wall tank within a diked enclosure relies on a separate bund; an above-ground containment vault encloses a tank inside a concrete enclosure that also provides fire and impact resistance. {note}
+# Underground Tanks {toc}
−## The secondary containment type shall be specified based on the desired footprint, monitoring approach, and level of fire and impact protection required.
+## Underground Tank Construction {toc}
+### Requirements in this article apply where the datasheet selects underground placement.
+
+### An underground tank shall be of the construction and listing indicated in the datasheet.
+
```datasheet
−label: Secondary Containment Type
+label: Underground Tank Construction and Listing
type: radio
options:
− - Double-wall interstitial (factory-built)
− - Single-wall with diked enclosure
− - Containment vault (concrete enclosure)
−default: Double-wall interstitial (factory-built)
+ - "Steel to UL 58 with UL 1746 Part I sacrificial anode cathodic protection"
+ - "Steel to UL 58 with UL 1746 Part II fiberglass-clad composite exterior"
+ - "Steel to UL 58 with UL 1746 Part III fiberglass or polyethylene jacket"
+ - "Fiberglass-reinforced plastic to UL 1316"
```
−## Secondary containment shall provide a volume of at least 110% of the largest single tank's capacity per NFPA 30.
+### A cathodically protected steel tank is the lowest-cost steel construction and depends for its life on anodes that are tested after backfill and every three years and replaced when consumed; a composite tank bonds a fiberglass laminate to the steel so the steel never touches the soil and needs no anodes, at a higher price; a jacketed tank wraps the steel in a fiberglass or polyethylene outer shell that is also the secondary containment, so the interstice is the space between steel and jacket; a fiberglass tank has no steel to corrode and carries the longest corrosion warranty, deflects under backfill load so its bedding and backfill are gradation-controlled, and is lighter to set. Steel and fiberglass each hold about half of the new installations, so the field carries no default. {note}
−## For open diked enclosures exposed to weather, 40 CFR 112 requires the containment to hold the largest tank's full capacity plus accumulated precipitation; the dike must be sized for both.
+### An underground tank shall be of double-wall construction with an interstitial space that can be monitored over the whole bottom of the tank, whatever the secondary containment selection under Secondary Containment, as 40 CFR Part 280 requires of a new or replaced underground tank.
−## The secondary containment shall be of the same listing as the primary tank where factory double-wall construction is used.
+### A steel underground tank protected by sacrificial anodes shall be furnished with the anodes, the dielectric nozzle bushings, and the test station lead the UL 1746 Part I listing requires, and the structure-to-soil potential shall satisfy NACE SP0285 when tested under STI R051 after backfill.
−## Underground secondary containment shall comply with the 40 CFR 280 interstitial monitoring requirement for new and replacement tanks.
+### The exterior coating of a steel underground tank shall be inspected for holidays with a wet-sponge or a high-voltage holiday detector at the manufacturer's stated voltage after the tank is set and before backfill, and every holiday shall be repaired with the manufacturer's repair material before backfill proceeds.
−# Overfill Prevention and Spill Control {toc}
+### A fiberglass tank shall be furnished with the deflection gauge or measurement the manufacturer requires, and the vertical deflection of the shell after backfill shall not exceed the manufacturer's published limit.
−## Overfill protection ranges from a high-level alarm only, to a high-high alarm that shuts off the fill pump, to an automatic overfill prevention valve that mechanically restricts flow as the tank approaches full. The level of protection is driven by the delivery method and AHJ requirements. {note}
+## Underground Tank Burial and Flotation {toc}
−## The level of overfill protection shall be specified based on the delivery method and applicable AHJ requirements.
+### An underground tank shall be bedded on and surrounded by the backfill material the tank listing and the manufacturer's installation instructions specify, placed in the lifts and to the compaction those instructions state, from the bottom of the excavation to not less than 12 in. over the top of the tank.
+### Excavation of the tank pit, worker protection, and construction groundwater control shall conform to [[sync/earthwork]], any engineered excavation support or designed dewatering system shall conform to [[sync/excavation-support-and-dewatering]], and backfill above the tank backfill zone shall conform to [[sync/earthwork]] for the area in which the tank falls.
+
+### The bedding and the backfill against the shell are within this standard because the listing of a buried tank is conditioned on them: a fiberglass tank that is backfilled with the native clay deflects past its limit, and a steel tank bedded on a rock shears its coating at the first point load. [[sync/earthwork]] resumes above the tank backfill zone with the class and compaction for the paving or the lawn above. {note}
+
+### The cover over the tank shall be not less than NFPA 30 requires for the surface above it, and where vehicles pass over the tank, the cover shall include the reinforced concrete or asphalt slab NFPA 30 requires for traffic loading.
+
+### Where the top of the backfill is within [[parameter: frost-depth]] of the tank, the manufacturer shall confirm in writing that the tank, its risers, and its spill containers are rated for the frost heave the burial depth exposes them to.
+
+### An underground tank shall be restrained against flotation as indicated in the datasheet.
+
```datasheet
−label: Overfill Protection
+label: Underground Tank Flotation Restraint
type: radio
options:
− - High-level alarm only
− - High-high alarm with fill pump shutoff
− - Automatic overfill prevention valve
−default: High-high alarm with fill pump shutoff
+ - "Precast or cast-in-place deadman anchors with hold-down straps"
+ - "Reinforced concrete hold-down pad beneath the tank with hold-down straps"
+ - "None, backfill weight alone"
```
−## Each fill connection shall be provided with a spill containment bucket (catchment basin) to capture drips and disconnect spillage during delivery.
+### Deadman anchors are concrete beams set in the excavation beside the tank, placed and strapped before backfill with no cure time on the critical path; a hold-down pad is a slab the tank sits on and is strapped down to, which also gives a flat bed in a wet or soft excavation at the cost of a pour and a cure before the tank is set; no restraint is the arrangement where the groundwater stays below the tank through the seasonal high and the backfill alone outweighs the empty tank's buoyancy with the margin the manufacturer requires. {note}
+### The flotation restraint shall resist the buoyant force of the empty tank with groundwater at [[parameter: seasonal-high-groundwater-elevation]] with the factor of safety the tank manufacturer requires, and the calculation shall be submitted under this standard.
+
+### Hold-down straps shall be of the material, number, and spacing the tank manufacturer specifies for the tank, shall bear on the shell through the manufacturer's isolating pads, and shall not be welded to a steel tank or drawn tight enough to deflect a fiberglass tank.
+
+# Secondary Containment {toc}
+
+## Containment Construction {toc}
+
+### Each tank shall have the secondary containment indicated in the datasheet.
+
```datasheet
−label: Spill Containment Bucket
+label: Secondary Containment
+type: radio
+options:
+ - "Double-wall tank with a monitored interstitial space"
+ - "Single-wall tank within an open diked enclosure"
+ - "Single-wall tank within a closed containment vault"
+default: "Double-wall tank with a monitored interstitial space"
+```
+
+### A double-wall tank carries its containment in its own shell, so the footprint is the tank's, the interstice is monitored by one sensor, and rain never enters the containment, which is why it is the default; an open dike holds a release from a single-wall tank in a bund that also collects rain and has to be drained through a valve that someone is responsible for, and it suits a large tank or a group of tanks where a double-wall shell would be heavier than a dike is costly; a closed containment vault encloses the tank in a concrete or steel enclosure that keeps rain out and adds impact and fire protection, and is the construction of the UL 2085 protected tank. {note}
+
+### Secondary containment shall hold not less than the full capacity of the largest tank within it, and where the containment is open to rainfall it shall also hold the precipitation the adopted fire code and 40 CFR Part 112 require it to retain.
+
+### The secondary containment of a double-wall tank shall be of the same listing as the primary tank and shall be tight to the test pressure or vacuum the listing assigns to the interstitial space.
+
+### An open diked enclosure shall drain through a normally closed valve that is locked closed, and the drain shall not discharge to a storm inlet or a watercourse except through the oil-water separation the adopted codes require.
+
+### The interstitial space of a double-wall tank shall be provided with a monitoring opening at the lowest point of the interstice and an emergency vent opening of the capacity the listing requires.
+
+### An interstice that cannot vent is a sealed annulus that over-pressures when the primary tank is engulfed in fire; the listing standards require the secondary to relieve the same fire exposure as the primary, which is why the emergency vent count on a double-wall tank is two. {note}
+
+## Leak Detection {toc}
+
+### The interstitial space or the containment of each tank shall be monitored by the method indicated in the datasheet.
+
+```datasheet
+label: Leak Detection Method
type: select
options:
− - 5 gal cast-iron spill bucket
− - 15 gal spill bucket
− - 5 gal poly spill bucket
−default: 5 gal cast-iron spill bucket
+ - "Liquid sensor in a dry interstitial space"
+ - "Hydrostatic brine-filled interstitial space with a reservoir level sensor"
+ - "Vacuum-monitored interstitial space"
+ - "Pressure-monitored interstitial space"
+ - "Liquid sensor in the dike or vault sump"
+ - "Groundwater or vapor monitoring wells around the excavation"
+default: "Liquid sensor in a dry interstitial space"
```
−## Where a bulk tank feeds a day tank through a transfer pump, the day tank high-level sensor shall shut off the transfer pump.
+### A liquid sensor at the low point of a dry interstice alarms when fuel from the primary or water from the secondary reaches it, costs one sensor and one pair of wires, and is the method on most double-wall tanks, which is why it is the default; a brine-filled interstice reads a leak in either wall as a change of level in a reservoir on top of the tank and detects an outer-wall breach that a dry sensor cannot see, at the cost of a reservoir to keep filled; vacuum and pressure monitoring hold the interstice at a set vacuum or pressure and alarm on a loss, which proves the integrity of both walls continuously rather than waiting for liquid to arrive, at the cost of a pump or a gas supply and a gauge to watch; a sump sensor is the method for a single-wall tank in a dike or vault, where there is no interstice; monitoring wells sample the groundwater or the soil vapor around an underground tank and are a method the federal rule accepts only where the site hydrogeology allows, so they are chosen for a single-wall or an existing tank rather than for new work. {note}
−## The day-tank overflow interlock is a frequent gap: if neither the tank specification nor the pump specification claims it, it goes unaddressed until startup. This standard assigns the day-tank high-level shutoff interlock to the tank package so the wiring path is defined. {note}
+### Groundwater or vapor monitoring wells shall be used only where the datasheet selects underground placement and where the Contractor submits the site assessment 40 CFR Part 280 requires for that method.
−# Venting {toc}
+### A leak detection sensor and the device that reads it shall alarm a release within the time 40 CFR Part 280 allows for the method where the tank is a regulated underground tank, and continuously where the datasheet selects an electronic sensor.
−## Normal venting relieves the pressure and vacuum produced during filling, withdrawal, and thermal breathing and is sized per API 2000. Emergency venting relieves the much larger vapor-generation rate produced when the tank is exposed to fire and is sized per NFPA 30 Table 22.7.3.2 or API 2000. Both are required; the emergency vent is not a substitute for the normal vent. {note}
+### Each leak detection sensor shall be removable through its riser or opening for test and replacement without entering the interstice or draining the tank.
−## Each tank shall be provided with a normal vent sized per API 2000 for the maximum fill and withdrawal rates.
+### Leak detection sensors shall be wired to the monitoring console indicated in the datasheet.
```datasheet
−label: Normal Vent Configuration
+label: Tank Monitoring Console
type: radio
options:
− - Atmospheric (open) vent
− - Pressure-vacuum vent
−default: Atmospheric (open) vent
+ - "Monitoring console furnished with the tank"
+ - "No console with the tank, sensors terminated in a junction box at the tank for the fuel-oil system console"
```
−## Each tank shall be provided with emergency venting sized to relieve the fire-exposure vapor-generation rate per NFPA 30.
+### A console furnished with the tank arrives matched to the tank's sensors, reads the leak sensor and the level probe on one display, logs the alarms the state program requires an underground tank to keep, and is the arrangement for a bulk tank that is the only tank at the site; a junction box hands the sensors to the console the fuel-oil system furnishes where several tanks, the pumps, and the day-tank levels are monitored together, so that the plant has one console rather than one per tank. The choice follows the number of tanks and who furnishes the pumps, so the field carries no default. {note}
−## The normal vent line shall be not smaller than 1.25 in for aboveground tanks per NFPA 30.
+### Where the tank is a generator sub-base tank, the leak detection sensor shall be wired to the generator controller and annunciated as [[sync/generators]] requires, whatever the console selection above.
−## The fill line shall be not smaller than 2 in for aboveground tanks per NFPA 30.
+### Where a console is furnished with the tank, it shall display the state of each sensor, shall alarm audibly and visually at the console, shall provide a dry contact for each alarm for connection to the plant monitoring system, and shall retain an alarm log where the tank is a regulated underground tank.
−## Vent outlets shall terminate at least 12 ft above finished grade, at least 5 ft above the fill point, and away from building openings per NFPA 30.
+# Fill Connection and Overfill Prevention {toc}
−## Vent termination conflicts are best resolved early: NFPA 30 keeps the outlet high and clear of openings, so coordinate vent routing against the building facade, HVAC intakes, and overhead structure before fabrication. Vent routing locations are shown on the drawings: [[drawing: tank vent routing and termination]]. {note}
+## Fill Point {toc}
−# Leak Detection and Gauging {toc}
+### Each tank shall be filled through the fill point indicated in the datasheet.
−## Leak Detection {toc}
+```datasheet
+label: Fill Point Location
+type: radio
+options:
+ - "Fill connection on the tank"
+ - "Remote fill station"
+default: "Fill connection on the tank"
+```
−### Interstitial monitoring with a liquid-sensing or hydrostatic sensor is standard for double-wall tanks. Vacuum and pressure monitoring continuously verify interstitial integrity. A groundwater monitoring well is an underground-only method used where interstitial monitoring is not feasible. {note}
+### A fill connection on the tank puts the driver, the spill container, the gauge, and the overfill alarm in one place where the driver can watch all of them, and is the arrangement of nearly every tank a delivery truck can reach, which is why it is the default; a remote fill station is a cabinet at the curb or on an exterior wall piped to a tank the truck cannot reach, and it moves the spill container and the overfill alarm to the cabinet and adds fill piping furnished under [[sync/fuel-oil-systems]]. {note}
−### The leak detection method shall be specified based on the tank's containment configuration and, for underground tanks, the feasibility of interstitial monitoring.
+### The fill connection shall be of the nominal size indicated in the datasheet, threaded or flanged to match the fill adapter.
```datasheet
−label: Leak Detection Method
+label: Fill Connection Size
+type: range
+unit: in.
+min: 2
+max: 4
+setpoints: [2, 3, 4]
+default: 2
+```
+
+### A 2 in. fill matches the hose and the tight-fill adapter of the fuel delivery trucks that serve generator and heating oil tanks and is the size on nearly every such tank; a 3 in. or 4 in. fill is used on a bulk tank of several thousand gallons filled by transport trailer at a rate a 2 in. fill would throttle, and the vent has to be sized for that fill rate. {note}
+
+### The fill connection shall be furnished with a tight-fill adapter of the pattern the fuel supplier's delivery hose uses, a lockable dust cap, and a drop tube extending to within 6 in. of the bottom of the tank.
+
+### A drop tube that ends above the liquid lets the fuel fall through the vapor space, which splashes, aerates the fuel, and builds a static charge; one that reaches near the bottom fills from below the surface and keeps the water and sludge there from being stirred into suspension. {note}
+
+### Where the datasheet selects a remote fill station, the station shall house the spill container, the fill adapter and cap, the overfill alarm indicator, and the gauge or indicator the driver reads, in a lockable weatherproof cabinet, and the fill piping from the station to the tank shall be furnished under [[sync/fuel-oil-systems]].
+
+## Spill Containment at the Fill {toc}
+
+### Each fill connection shall be furnished with a spill container around the fill adapter of the capacity indicated in the datasheet.
+
+```datasheet
+label: Spill Container Capacity
+type: range
+unit: gal
+min: 5
+max: 25
+setpoints: [5, 7, 15, 25]
+```
+
+### Five gallons is the minimum the fire code accepts at an aboveground fill, the usual size of the catchment basin the federal underground tank rule requires, and holds the drain-back of a 2 in. delivery hose; a 7 gal container is the capacity of the fill box on most aboveground tanks; 15 and 25 gal containers hold the drain-back of a transport hose or the spill of a fill that was not shut off at the alarm, and they are the containers at a bulk tank filled by trailer. The capacity follows the hose and the fill rate, so the field carries no default. {note}
+
+### Spill containers shall be of the construction indicated in the datasheet.
+
+```datasheet
+label: Spill Container Construction
type: radio
options:
− - Interstitial sensor (electronic)
− - Vacuum monitoring
− - Pressure monitoring
− - Groundwater monitoring well (UST only)
−default: Interstitial sensor (electronic)
+ - "Single-wall"
+ - "Double-wall with an interstitial test port"
```
−### The leak-detection system shall alarm a confirmed leak within the response time required by 40 CFR 280.43 for underground tanks.
+### A single-wall spill container on an underground tank is tested for tightness every three years under the federal rule; a double-wall container with a monitored or testable interstice is exempt from that test, so the second wall is bought against a recurring test on a part that sits in traffic and ice. On an aboveground tank the container is in sight and is emptied by hand, so a second wall buys little. {note}
−### Continuous electronic interstitial monitoring achieves near-real-time leak response and is preferred over the 30-day maximum allowed by 40 CFR 280.43. {note}
+### Each spill container shall drain to the tank through a normally closed drain valve or be emptied by hand, shall have a liquid-tight lid that excludes rain, and shall be of a material rated for the fuel.
−### The interstitial monitoring sensor is furnished under this tank standard, but the monitoring panel and home-run wiring are often carried in the electrical specification. {note}
+## Overfill Prevention {toc}
−### The Contractor shall coordinate the monitoring panel and home-run wiring so the interstitial sensor is connected and supervised; if neither the tank nor the electrical scope claims it, it goes un-bid.
+### Each tank filled by pump from a delivery vehicle shall be furnished with the overfill prevention indicated in the datasheet.
−## Level Gauging {toc}
+```datasheet
+label: Overfill Prevention
+type: radio
+options:
+ - "High-level alarm at the fill point, audible and visible to the delivery operator"
+ - "Automatic shutoff valve in the fill line"
+ - "High-level alarm at the fill point and automatic shutoff valve in the fill line"
+```
−### Level gauging ranges from a mechanical float gauge for local indication, to an electronic level transmitter, to a continuous ultrasonic gauge; the electronic and ultrasonic options integrate with the building monitoring system for remote indication and alarming. {note}
+### A high-level alarm at the fill point warns the driver at the level NFPA 30 sets and relies on the driver to close the delivery valve, which is the arrangement where the fuel supplier's own procedure is trusted and the valve is in reach; an automatic shutoff valve in the fill line closes on its own at the fill limit and is what protects a tank filled by a driver who has walked away, but a valve that closes against a pumping truck sends a pressure surge back up the hose, so it is paired with an alarm that warns the driver first on most tanks that take both. The fire code accepts any of the three for a tank that receives fuel by pump, and a state program or an Authority Having Jurisdiction sometimes requires the valve, so the field carries no default. {note}
−### The level gauging method shall be specified, including whether integration with the building monitoring system for remote indication is required.
+### The high-level alarm shall actuate at not more than 90 percent of the nominal capacity, shall be independent of the level gauge, and shall sound and light at the fill point until acknowledged there.
+### The automatic shutoff valve shall close at not more than 95 percent of the nominal capacity, shall be listed for the fuel, and shall be of a type that can be tested in place without filling the tank to the shutoff level.
+
+### A ball-float vent valve shall not be used as the overfill prevention device on a new tank.
+
+### An overfill alarm that is lit at the console in a room the driver cannot see protects nothing at the fill; the alarm the fire code intends is the one the person holding the hose hears, which is why the alarm is placed at the fill point and why the console alarm is an additional contact rather than a substitute. {note}
+
+# Venting {toc}
+
+## Normal Venting {toc}
+
+### Each tank shall be furnished with a normal vent opening and vent device sized under API Std 2000 or NFPA 30 for the greater of the maximum fill rate and the maximum withdrawal rate, and the normal vent shall be not smaller than 1-1/4 in. nominal.
+
+### The normal vent device shall be as indicated in the datasheet.
+
```datasheet
+label: Normal Vent Device
+type: radio
+options:
+ - "Open vent with weatherproof cap and insect screen"
+ - "Pressure-vacuum vent"
+default: "Open vent with weatherproof cap and insect screen"
+```
+
+### An open vent lets the tank breathe freely as it fills, empties, and warms, and is the vent on nearly every diesel and heating oil tank because a Class II or Class III liquid gives off too little vapor at ambient temperature for the vent to matter, which is why it is the default; a pressure-vacuum vent holds a small pressure and vacuum before it opens, which limits evaporative loss and keeps moist air out of a tank that is stored full for long periods, at the cost of a device that has to be sized for the fill rate and inspected. {note}
+
+### The normal vent opening on a double-wall tank shall be on the primary tank, and the interstitial space shall not be vented through the primary tank's normal vent.
+
+## Emergency Venting {toc}
+
+### Each aboveground tank, and the interstitial space of each double-wall aboveground tank, shall be furnished with an emergency vent opening and device sized under NFPA 30 for the wetted area of the tank, and the emergency vent shall be of the type indicated in the datasheet.
+
+```datasheet
+label: Emergency Vent Device
+type: radio
+options:
+ - "Spring-loaded emergency vent"
+ - "Long-bolt manway cover"
+default: "Spring-loaded emergency vent"
+```
+
+### A spring-loaded vent lifts at a set pressure, reseats when the pressure falls, and is the device the manufacturers fit to the emergency vent opening of nearly every shop-built tank, which is why it is the default; a long-bolt manway cover lifts on its bolts under fire pressure and serves a large tank whose manway is already the largest opening on the shell, and it does not reseat. {note}
+
+### An emergency vent shall relieve at a pressure not exceeding the design pressure of the tank and shall be marked with its relieving capacity.
+
+### The emergency vent relieves the vapor a tank generates when a fire boils the fuel inside it, a rate hundreds of times the normal breathing rate; a tank without one ruptures at the weld in that fire, and a double-wall tank whose interstice has none ruptures the outer shell. Neither vent is a substitute for the other. {note}
+
+### An underground tank shall not be furnished with an emergency vent, and its normal vent shall be sized for the fill rate as NFPA 30 requires of a buried tank.
+
+## Vent Terminations {toc}
+
+### Vent openings and devices shall be located on the tank so that the vent piping furnished under [[sync/fuel-oil-systems]] can terminate outdoors, above the fill opening, and at the height above grade and the distance from building openings, air intakes, and sources of ignition that NFPA 30 requires for the tank's placement and the fuel's class.
+
+### A sub-base tank and a day tank whose vents terminate at the tank shall have those vents terminate as the preceding clause requires, with the termination fitting furnished on the tank.
+
+# Level Gauging and Alarms {toc}
+
+## Level Gauging {toc}
+
+### Each tank shall be furnished with the level gauging indicated in the datasheet.
+
+```datasheet
label: Level Gauging
+type: select
+options:
+ - "Direct-reading mechanical float gauge at the tank"
+ - "Magnetostrictive probe with the monitoring console"
+ - "Hydrostatic pressure level transmitter"
+ - "Ultrasonic level transmitter"
+ - "Guided-wave radar level transmitter"
+ - "Point-level switches only, no continuous gauge"
+```
+
+### A mechanical float gauge reads with no power at the tank and nothing anywhere else, and is the gauge the delivery driver reads before the hose is connected; a magnetostrictive probe reads level and bottom water to a fraction of an inch into a console that also runs the leak detection and the inventory record the state program requires of an underground tank, so it is the gauge of the regulated tank; a hydrostatic transmitter reads the head at the bottom nozzle on a two-wire loop and is the lowest-cost continuous signal to a remote system; an ultrasonic transmitter reads from the top with nothing in the fuel and loses its echo in foam and vapor; a guided-wave radar reads along a probe unaffected by vapor, density, or foam at the highest price of the group; point switches alone give the alarms and no inventory, for a day tank whose level is run by its own controls. Which gauge a tank gets follows from who reads it and what the record has to show, so the field carries no default. {note}
+
+### Where the level gauge provides an analog output to a plant monitoring system, the output signal and the hazardous-location protection shall be as selected under [[sync/pressure-instrumentation]].
+
+### Where temperature elements are furnished on a tank for fuel temperature monitoring, their output signal and hazardous-location protection shall be as selected under [[sync/temperature-instrumentation]].
+
+### A level gauge shall be readable from grade or from the fill point without a ladder, and a mechanical gauge shall be graduated in gallons or in fractions of the nominal capacity.
+
+## Level and Leak Alarm Contacts {toc}
+
+### Each tank shall be furnished with the alarm contacts indicated in the datasheet, each as a dry contact wired to the console or junction box selected under Leak Detection.
+
+```datasheet
+label: Alarm Contacts
+type: checkbox
+options:
+ - "High level"
+ - "Low level"
+ - "Critical low level"
+ - "Interstitial or containment leak"
+ - "Bottom water"
+default:
+ - "High level"
+ - "Low level"
+ - "Interstitial or containment leak"
+```
+
+### The high-level contact is the overfill alarm's contact and reports at the console that a fill approached the limit; the low-level contact is the fuel-ordering alarm that keeps a generator tank from being found empty at the start of an outage; a critical-low contact at a level above the suction dead volume warns that the engine is about to lose fuel and is set below the low-level alarm; the leak contact is the leak detection sensor's; a bottom-water sensor reports the water that collects under a stored distillate and feeds the microbial growth that plugs filters, and is the contact a tank that stores fuel for years benefits from. {note}
+
+### Alarm setpoints shall be as indicated on [[drawing: the fuel system flow diagram]], and the set levels shall be recorded on the functional test record.
+
+### Where the tank serves an engine-generator, the low-fuel pre-alarm level shall be the level [[sync/generators]] requires for the set's runtime, and the contact shall also be wired to the generator controller as that standard requires.
+
+# Electrical Devices on the Tank {toc}
+
+## Enclosure Rating {toc}
+
+### Junction boxes, alarm indicators, sensor housings, and the monitoring console where one is furnished with the tank shall carry at least the enclosure rating indicated in the datasheet, rated under NEMA 250 or UL 50E.
+
+```datasheet
+label: Minimum Enclosure Rating
+type: select
+options:
+ - "NEMA Type 1"
+ - "NEMA Type 3R"
+ - "NEMA Type 4"
+ - "NEMA Type 4X"
+ - "NEMA Type 12"
+ - "NEMA Type 7"
+default: "NEMA Type 3R"
+```
+
+### Type 3R is the default because the fuel tank and the devices on it normally sit outdoors, and it excludes rain and sleet and lets condensation drain; Type 1 serves a console or a day-tank junction box inside a dry room; Type 4 excludes hose-directed water and wind-driven rain for a device at grade where a truck apron is washed down; Type 4X adds corrosion resistance for salt air and chemical fumes; Type 12 excludes dust and dripping non-corrosive liquid indoors; Type 7 is the explosion-proof construction for a Class I, Division 1 location. The clauses that follow raise the rating for the locations that need more, whatever the datasheet selects. {note}
+
+### Enclosures mounted outdoors shall be rated NEMA Type 3R, Type 4, or Type 4X.
+
+### Enclosures mounted where they are subject to washdown or hose-directed water shall be rated NEMA Type 4 or Type 4X.
+
+### Enclosures mounted where they are exposed to salt air, corrosive fumes, or washdown chemicals shall be rated NEMA Type 4X.
+
+### Enclosures in a Class I, Division 1 location where an explosion-proof enclosure is the means of protection shall be rated NEMA Type 7 in addition to the rating required for the environment.
+
+## Hazardous Locations at the Tank {toc}
+
+### The hazardous-location classification at each tank shall be as indicated on [[drawing: the electrical area classification drawings]], and every electrical device on the tank shall be listed for the class, division, and group at its location.
+
+### A tank storing a Class II or Class III liquid below its flash point is not itself a classified location under NFPA 30, but the tank vent and the fill of a tank storing a heated oil, and every propane container under NFPA 58, sit in Class I locations whose extent the code tables define; the area classification drawing is where that determination is recorded, so the tank's devices are listed to it rather than to an assumption about the fuel. {note}
+
+### Sensors and probes that enter the tank or the interstitial space shall be intrinsically safe or shall be of a construction listed for the location, and intrinsically safe sensors shall be connected through the barrier the console or the sensor manufacturer specifies.
+
+### Metal tanks, fill connections, and vent devices shall be bonded to the grounding electrode system under [[sync/grounding-and-bonding]], and the fill connection shall carry a bonding point for the delivery vehicle's bonding cable.
+
+# Anchorage and Flotation {toc}
+
+## Aboveground Tank Anchorage {toc}
+
+### Each aboveground tank shall be anchored to its foundation for the seismic and wind loads [[parameter: adopted-building-code]] assigns to a nonbuilding structure of its weight and location, with the seismic demand determined under ASCE 7 for [[parameter: seismic-design-category]].
+
+### The anchorage calculation for each aboveground tank shall be sealed by a professional engineer as indicated in the datasheet.
+
+```datasheet
+label: Sealed Anchorage Calculation
type: radio
options:
− - Mechanical float gauge (local)
− - Electronic level transmitter
− - Continuous ultrasonic gauge
−default: Electronic level transmitter
+ - "Sealed by a professional engineer licensed in the project jurisdiction"
+ - "Prepared by the tank manufacturer without a seal"
+derived: "[[parameter: seismic-design-category]] and the operating weight of the tank"
+default: derived
```
−### A level transmitter that reports to the building monitoring system shall interface per [[sync/pressure-instrumentation]] signal conventions where an analog output is provided.
+### A tank in Seismic Design Category C or higher, or one whose operating weight makes it a nonbuilding structure the building code reviews, is anchored to a sealed calculation because the Authority Having Jurisdiction will ask for one at permit; a small tank in Seismic Design Category A or B is anchored to the manufacturer's standard detail. The requirement follows from the category and the weight, so the field points at them. {note}
−# Anchorage and Corrosion Protection {toc}
+### Anchor bolts shall be of the type indicated in the datasheet.
−## Seismic Anchorage {toc}
+```datasheet
+label: Anchor Type
+type: radio
+options:
+ - "Cast-in anchor rods"
+ - "Post-installed anchors"
+```
−### Aboveground tanks in Seismic Design Categories C through F shall be anchored and restrained per ASCE 7 Chapter 15 for nonbuilding structures.
+### Cast-in anchor rods are set to a template before the pad is poured and develop their full capacity in the concrete, which suits a new pad poured for the tank from the shop drawing's bolt pattern; post-installed anchors are drilled after the pad cures to the tank as it actually sits, which suits a tank set on an existing pad or one whose shop drawings arrive after the pad is poured, at a lower capacity per anchor and a qualification under ACI 318 Chapter 17 that the calculation has to carry. {note}
−### Aboveground tanks exceeding 50,000 lb operating weight require PE-stamped seismic anchorage calculations in SDC C and above. The anchorage interfaces with the supporting concrete or steel per [[sync/structural-steel-anchor-bolts]] and [[sync/grouted-base-plates]]. {note}
+### Cast-in anchor rods shall conform to [[sync/structural-steel-anchor-bolts]], and post-installed anchors shall conform to [[sync/post-installed-anchors]], each of the grade, diameter, embedment, and pattern the anchorage calculation states.
−### Tank anchorage to the foundation shall be designed for the seismic and wind reactions delivered to the saddles or skid.
+### Anchor clips, lugs, and saddle base plates shall be welded to the tank by the tank manufacturer and shall be sized for the reactions the anchorage calculation delivers to them.
−## Underground Buoyancy {toc}
+## Vehicle Impact Protection {toc}
−### An empty underground tank in a high-water-table soil will float; anchor straps and a holddown slab or deadman must be sized for the buoyant force of the empty tank. This calculation is frequently omitted in preliminary design and must be completed before the tank is set. {note}
+### An aboveground tank or propane container exposed to vehicle traffic shall be protected by bollards or barriers furnished under [[sync/site-furnishings-and-bollards]] at the locations indicated on [[drawing: the site plan]], or shall be listed to UL 2085 where the datasheet selects that listing in place of barriers.
−### Underground tank anchorage shall be designed for the buoyant uplift of the empty tank at the maximum design water table.
+# Propane Containers {toc}
+## Propane Container Scope {toc}
+
+### Requirements in this article apply where a tank under this standard stores liquefied petroleum gas for an engine-generator, a boiler, or other on-site equipment.
+
+### A propane container is a pressure vessel rather than an atmospheric tank, so none of the listing, containment, venting, or overfill articles for liquid fuel tanks apply to it; NFPA 58 governs its construction, its valves, its siting, and its filling, and this article carries the vessel-side selections. The container's vapor withdrawal rate at the site's low temperature is checked under [[sync/generators]] for a generator and under [[sync/boilers]] for a boiler, and the first-stage regulator at the service valve begins the piping under [[sync/fuel-gas-piping]]. {note}
+
+### The propane container shall be procured as indicated in the datasheet.
+
```datasheet
−label: UST Buoyancy Anchorage
+label: Propane Container Procurement
type: radio
options:
− - Anchor straps to holddown slab
− - Concrete holddown slab (ballast)
− - Deadman anchors
−default: Anchor straps to holddown slab
+ - "Container purchased and furnished under this standard"
+ - "Container leased from the propane supplier and set under the supplier's agreement"
```
−## Cathodic Protection {toc}
+### A purchased container is the Owner's, is specified, submitted, and tested like any other vessel under this standard, and is filled by any supplier; a leased container is the supplier's, arrives with the supplier's valves and gauge, is set by the supplier to NFPA 58, and ties the Owner to that supplier's fuel for the lease term, at no capital cost. Which the Owner wants is a commercial decision, so the field carries no default. {note}
−### Steel underground tanks shall be provided with external corrosion protection per UL 1746 and cathodic protection per NACE SP0285.
+### Where the datasheet selects a leased container, the Contractor shall furnish the foundation, the anchorage, the protection from vehicles, and the area classification coordination under this standard, and shall obtain from the supplier the container data and the siting plan the Action Submittals require.
+## Propane Container Construction and Placement {toc}
+
+### The propane container shall be designed, fabricated, tested, and stamped to ASME BPVC Section VIII, Division 1 for a design pressure not less than NFPA 58 requires for propane, shall be registered with the National Board, and shall carry the nameplate data NFPA 58 requires.
+
+### The propane container shall be placed as indicated in the datasheet.
+
```datasheet
−label: Cathodic Protection (Steel USTs)
+label: Propane Container Placement
type: radio
options:
− - Sacrificial magnesium anode
− - Impressed-current system
− - Not required (fiberglass tank)
−default: Sacrificial magnesium anode
+ - "Aboveground on saddles or legs"
+ - "Underground"
+ - "Mounded"
+default: "Aboveground on saddles or legs"
```
−### Cathodic protection uses either sacrificial magnesium anodes sized per NACE SP0285, or an impressed-current system meeting the -850 mV protective-potential criterion of NACE SP0169. Sacrificial systems are simpler and need no external power; impressed-current systems suit larger or higher-resistivity installations. {note}
+### An aboveground container is set on a pad, inspected by sight, and is the placement of most containers serving a generator or a boiler, which is why it is the default; an underground container disappears from the site, is permitted at shorter separation distances under NFPA 58, and brings a coating, cathodic protection, and a dome over its valves that NFPA 58 requires of a buried container; a mounded container is an aboveground container covered with earth, which gives the fire protection of burial without an excavation, at the cost of the mound and the same coating and cathodic protection. {note}
−# Testing {toc}
+### The propane container shall have the water capacity indicated in the datasheet.
−## Each tank shall be factory pressure-tested and certified before shipment.
+```datasheet
+label: Propane Container Water Capacity
+type: range
+unit: gal
+derived: "the runtime or delivery interval established under the served equipment standard, the full-load propane consumption of the served equipment, the maximum filling limit NFPA 58 imposes for the container's placement, and the vapor withdrawal rate the container surface delivers at [[parameter: site-ambient-temperature-minimum]]"
+min: 120
+max: 30000
+setpoints: [120, 250, 325, 500, 1000, 1450, 1990, 2500, 3900, 5000, 6000, 12000, 18000, 30000]
+default: derived
+```
−## UL 142 requires a pneumatic factory test at 3 to 5 psi held for 30 minutes with all welds inspected. The certificate accompanies the tank as an informational submittal. {note}
+### A propane container is filled only to the limit NFPA 58 sets for its placement, about 80 percent of its water capacity for an aboveground container, and the vapor the engine or burner draws is boiled off the surface of the liquid by the heat the container takes from the air, so a container can hold enough fuel by volume and still starve the load on a cold night when the liquid is low; the capacity follows from the runtime and the consumption like a diesel tank's, with the vaporization check added, and the sizes offered are the catalog sizes the ASME shops build. {note}
−## The Contractor shall field-acceptance-test the tank vessel and secondary containment after installation per NFPA 30.
+### The propane container shall be furnished with the filler valve, the pressure relief valve of the capacity NFPA 58 requires for the container, the fixed maximum liquid level gauge, the float gauge, the vapor service valve with an excess-flow or back-check function, the liquid withdrawal valve where one is required, and the pressure gauge that NFPA 58 requires for a container of its capacity, each listed for propane.
−## The field acceptance test shall be pneumatic or hydrostatic at the pressure and duration required by NFPA 30 and the AHJ. {note}
+### The container's pressure relief valve shall discharge upward and away from the container, and on an underground or mounded container shall vent through the dome to the height above grade NFPA 58 requires.
−## The interstitial space of a double-wall tank shall be tested for integrity, by vacuum or pressure, before the tank is placed in service.
+### The propane container shall be located as indicated on [[drawing: the site utility plan]] and shall satisfy the separation distances NFPA 58 requires from buildings, property lines, sources of ignition, and other containers for its water capacity and placement.
−## The cathodic protection system shall be commissioned and protective potentials recorded before backfill is completed over the tank connections.
+### An aboveground propane container shall be set on a concrete foundation constructed under [[sync/concrete-pads]] or [[sync/shallow-foundations]] and anchored for the wind and seismic loads [[parameter: adopted-building-code]] assigns, with the anchorage calculation sealed as the Sealed Anchorage Calculation selection above requires.
+### An underground or mounded propane container shall be coated and cathodically protected as NFPA 58 requires of a buried container, shall be restrained against flotation with groundwater at [[parameter: seasonal-high-groundwater-elevation]], and shall be furnished with a dome over its valves that keeps the valves above the surrounding grade and out of standing water.
+
+### An aboveground propane container shall be painted a heat-reflective light color, and every container shall be marked as NFPA 58 requires with the product name and the hazard identification.
+
+# Testing {toc}
+
+## Factory Testing {toc}
+
+### Each liquid fuel tank shall be tightness tested at the factory at the pressure and for the duration its listing standard requires, for the primary tank and for the interstitial space, and the certificate shall be submitted under Informational Submittals.
+
+### Each propane container shall be hydrostatically tested at the factory as ASME BPVC Section VIII, Division 1 requires, and the manufacturer's data report shall be submitted under Action Submittals.
+
+## Field Tightness Testing {toc}
+
+### After the tank is set and before it is connected or backfilled, the Contractor shall tightness test the primary tank and the interstitial space by the method indicated in the datasheet, at the pressure or vacuum and for the duration the tank manufacturer and NFPA 30 require, and shall record the result.
+
```datasheet
−label: Field Acceptance Test Method
+label: Field Tightness Test Method
type: radio
options:
− - Pneumatic (air) test
− - Hydrostatic test
−default: Pneumatic (air) test
+ - "Pneumatic test of the primary with soap solution on every weld and fitting"
+ - "Hydrostatic test of the primary"
+ - "Vacuum test of the interstitial space with the primary tested pneumatically"
+default: "Pneumatic test of the primary with soap solution on every weld and fitting"
```
+### An air test at the few pounds the listing allows, with soap solution on every seam and plug, finds a pinhole the eye cannot and is the test every tank manufacturer's instructions call for, which is why it is the default; a hydrostatic test puts no stored energy in the shell but leaves water in a fuel tank that then has to be dried, and it is the test an Authority Having Jurisdiction sometimes requires of a large tank; a vacuum test of the interstice proves the secondary tight by pulling a vacuum and watching it hold, and some manufacturers ship a tank under factory vacuum so that the gauge at delivery is the test. {note}
+
+### A tank shall not be pressurized above the test pressure the manufacturer states, and a fiberglass tank shall not be pressure tested with liquid.
+
+### A tank or interstitial space that fails a field tightness test shall be repaired by the manufacturer or replaced, and the test repeated at the Contractor's expense.
+
+### Where the state underground tank program or the Authority Having Jurisdiction requires a precision tightness test of an underground tank after installation, the Contractor shall perform it by a method the program accepts, before the tank is placed in service, at the Contractor's expense.
+
+## Functional Testing of Appurtenances {toc}
+
+### After installation and before the tank is placed in service, the Contractor shall exercise each leak detection sensor, each level alarm contact, and the overfill alarm by simulating the condition at the sensor, and shall confirm that each alarm is received at the console, the generator controller, or the plant monitoring system the datasheet sends it to.
+
+### The automatic shutoff valve, where furnished, shall be tested in place by the method its manufacturer specifies, and the test recorded on the functional test record.
+
+### The cathodic protection of a steel underground tank shall be commissioned under STI R051 after backfill, and the structure-to-soil potentials recorded with the test station location on the commissioning record.
+
+### The leak detection functional test, the overfill alarm test, and the cathodic protection commissioning shall be witnessed by the Owner's representative, who shall be notified in writing not less than five working days before each test.
+
# Installation {toc}
−## Tanks shall be installed in accordance with the manufacturer's instructions, NFPA 30, IFC Chapter 57, and PEI RP200 for aboveground systems.
+## Setting Aboveground Tanks {toc}
−## Aboveground tanks shall maintain the separation distances from buildings, property lines, and ignition sources required by NFPA 30 and the IFC.
+### Aboveground tanks shall be installed in accordance with the manufacturer's instructions, NFPA 30, the adopted fire code, NFPA 37 where the tank serves an engine, NFPA 31 where it serves a burner, and PEI RP200 for the installation practices it covers.
−## Tanks serving stationary engine-generators shall maintain the fuel-storage clearances of NFPA 37.
+### Aboveground tanks shall be set at the separation distances from buildings, property lines, public ways, and sources of ignition that NFPA 30 and the adopted fire code require for the tank's listing and capacity.
−## Underground tanks shall be set on and surrounded by clean, non-corrosive backfill of the gradation required by the tank listing.
+### Tanks shall be lifted only at the manufacturer's lifting lugs, with the spreader bar the manufacturer specifies where one is specified, and never by the nozzles, the vents, or a sling around a coated shell.
−## Tank-area surface drainage shall be graded so that a containment release or spill is directed away from storm inlets and coordinated with [[sync/stormwater-management-systems]].
+### Tanks shall be set level on the pad within the manufacturer's tolerance, with the drain or water draw-off at the low point, and shimmed only with the full-bearing shims the manufacturer permits.
−## Tank fill, vent, and gauge connections shall be terminated and capped pending connection of the fuel system furnished under [[sync/fuel-oil-systems]].
+### Tank fill, vent, supply, return, and gauge nozzles shall be protected with caps or plugs until the fuel-oil system connects to them under [[sync/fuel-oil-systems]], and the Contractor shall make no connection to a nozzle that puts load on the shell.
−## Tank temperature monitoring, where provided, shall interface per [[sync/temperature-instrumentation]] signal conventions.
+### Grading around an aboveground tank shall direct a release away from building openings and storm inlets, coordinated with [[sync/site-rough-grading]], and a tank shall not be set where surface water ponds against the shell or the supports.
−# Long-Term Fuel Quality {toc}
+## Setting Underground Tanks {toc}
−## Ultra-low-sulfur diesel stored more than 6 to 12 months without biocide treatment or fuel polishing promotes microbial growth and filter plugging. NFPA 110 reliability intent is met by a fuel-management program, not by tank sizing alone. {note}
+### Underground tanks shall be installed in accordance with the manufacturer's instructions, NFPA 30, the adopted fire code, 40 CFR Part 280 and the state program, and PEI RP100.
−## The operation and maintenance manual shall include a fuel-management program covering periodic fuel testing, biocide treatment, and the polishing interval recommended for the stored fuel grade.
+### An underground tank shall be inspected for shipping damage, holidays in its coating, and interstitial vacuum on arrival and again immediately before it is lowered into the excavation, and a damaged tank shall not be set until the manufacturer has approved the repair in writing.
+### The excavation shall be free of standing water, debris, and sharp objects before bedding is placed, and the tank shall be set on the bedding without dropping and without dragging across the excavation.
+
+### Where an underground tank is set and cannot be backfilled the same day, the Contractor shall ballast the tank with the liquid and to the level the manufacturer specifies against a rise of groundwater, and shall not use fuel as ballast.
+
+### Hold-down straps shall be tensioned, the backfill placed and compacted in lifts around the tank, and the deflection of a fiberglass tank measured, in the sequence the manufacturer's instructions state, before any load is placed over the tank.
+
+### Risers for the fill, the vents, the gauge, and the monitoring openings shall terminate in a liquid-tight containment sump or a spill container at grade, and the containment sumps shall be of a construction that can be tested or monitored as 40 CFR Part 280 requires.
+
+## Protection Pending Connection {toc}
+
+### Until the tank is connected and placed in service, the Contractor shall keep the interstitial space dry, the spill containers lidded, the fill and vent openings capped, and the monitoring openings plugged, and shall remove any water that enters the interstice before the functional tests.
+
# Delivery, Storage, and Handling {toc}
−## Tanks shall be delivered with all nozzles plugged or capped and lifting lugs protected.
+## Tanks shall be delivered with every nozzle capped or plugged, with the lifting lugs protected, and with the listing label, the nameplate, and the fuel marking legible and undamaged.
−## Tanks shall be handled only at the manufacturer's designated lifting points; slings shall not be passed around the shell of a coated tank in a way that damages the coating.
+## Tanks shall be stored on level supports that bear on the saddles, skid, or the manufacturer's blocking, and never on the shell, and a coated tank shall be stored on supports that do not cut its coating.
−## Tanks shall be stored level and supported to prevent shell distortion.
+## A fiberglass tank and a jacketed steel tank shall be stored on the dunnage they ship on, chocked against rolling, and protected from sunlight where the manufacturer requires it.
−## Tanks shall be protected from standing water in the interstitial space prior to installation.
+## A tank stored at the site for more than 30 days shall be inspected monthly for standing water in the interstitial space and in the spill containers, and the water removed.
# Warranty {toc}
−## The manufacturer shall warrant the tank against defects in materials and workmanship, including perforation of the primary and secondary walls, for the period specified.
+## The tank manufacturer shall warrant each tank against defects in materials and workmanship, including leakage of the primary tank and the secondary containment, for the period indicated in the datasheet, measured from the date of substantial completion.
```datasheet
label: Tank Warranty Period
−type: select
−options:
− - 1 year
− - 5 years
− - 10 years
− - 30 years (FRP corrosion)
−default: 5 years
+type: range
+unit: years
+min: 1
+max: 30
+setpoints: [1, 2, 5, 10, 20, 30]
```
−## Fiberglass underground tanks are commonly available with an extended corrosion warranty reflecting their corrosion-immune construction; steel underground tank warranties are tied to the integrity of the external corrosion protection system. {note}
+## A steel aboveground tank carries a one- or two-year workmanship warranty from most manufacturers, a composite or jacketed steel underground tank carries a thirty-year warranty against corrosion and structural failure, and a fiberglass underground tank a thirty-year warranty on the same terms; the long warranties are conditioned on an installation inspected to the manufacturer's checklist, which is why the installation instructions and the warranty conditions are submitted together. The period follows the construction selected, so the field carries no default. {note}
+## The warranty shall cover the repair or replacement of the tank, its removal and reinstallation where it cannot be repaired in place, and the retesting of the tank after the repair.
+
+## Where a tank is repaired or replaced under warranty, the repaired or replaced tank shall carry a new warranty of the same term from the date of the repair, or the remainder of the original term, whichever ends later.
+
# Spare Parts {toc}
−## The Contractor shall furnish the following spare parts and consumables to the Owner:
−- One spare interstitial leak-detection sensor of each type installed.
−- One spare set of fill-cap and spill-bucket gaskets.
−- One spare overfill alarm float or sensor where a float type is used.
+## The Contractor shall deliver the spare parts indicated in the datasheet at substantial completion.
```datasheet
−label: Spare Parts
+label: Spare Parts Delivered at Substantial Completion
type: checkbox
options:
− - Spare interstitial leak-detection sensor
− - Spare fill-cap and spill-bucket gaskets
− - Spare overfill alarm float / sensor
+ - "Leak detection sensor of each type installed"
+ - "Level alarm float or probe of each type installed"
+ - "Fill cap and spill container gaskets of each size installed"
+ - "Normal vent cap of each size installed"
+ - "Emergency vent gasket of each size installed"
+ - "Manway gasket of each size installed"
default:
− - Spare interstitial leak-detection sensor
− - Spare fill-cap and spill-bucket gaskets
+ - "Leak detection sensor of each type installed"
+ - "Fill cap and spill container gaskets of each size installed"
```
+
+## Spare parts shall be furnished in the quantity of one of each selected class for every five tanks installed, with not fewer than one of each, shall match the installed parts in model and material, and shall be turned over against a written inventory signed by the Owner's representative.