Dry-Pipe Fire Sprinkler Systems
Corpus sync: neutrality remakes, note hygiene, datasheet relocation, transformer-split cross-refs
Showing changes from Rev 6
to Rev 7
in Dry-Pipe Fire Sprinkler Systems.
---
title: Dry-Pipe Fire Sprinkler Systems
…37 unchanged lines
## NFPA 13 Section 8.2 requires that wet-pipe systems be used wherever piping can be reliably maintained above 40°F (4°C). {note}
+## A dry-pipe system shall not be substituted for a wet-pipe system where a wet-pipe system is feasible.
+
+## Dry-pipe systems shall be selected only when freeze protection is required and when neither electric heat trace with insulation, antifreeze loops within the size limits permitted by NFPA 13, nor relocation of piping into conditioned space is practical.
+
+## The Engineer of Record shall document the rationale for selecting a dry-pipe system in lieu of a wet-pipe system in the basis-of-design narrative.
+
```datasheet
label: Reason for Dry-Pipe Selection
…12 unchanged lines
```
−## A dry-pipe system shall not be substituted for a wet-pipe system where a wet-pipe system is feasible.
−
−## Dry-pipe systems shall be selected only when freeze protection is required and when neither electric heat trace with insulation, antifreeze loops within the size limits permitted by NFPA 13, nor relocation of piping into conditioned space is practical.
−
−## The Engineer of Record shall document the rationale for selecting a dry-pipe system in lieu of a wet-pipe system in the basis-of-design narrative.
−
## Common decision drivers that justify a dry-pipe selection are piping in attics, joist spaces, or concealed ceiling spaces in cold climates where intermittent heating is uncertain; freezer warehouse and refrigerated storage room protection; unheated parking decks above grade; exterior canopies and walkways; unconditioned loading dock areas with overhead doors that defeat space heating; and mechanical rooms vented to outside air. {note}
…77 unchanged lines
### Working drawings shall be prepared by or under the supervision of a person with qualifications acceptable to the AHJ.
−### The Contractor shall confirm designer qualification requirements before assigning the design work, because in many jurisdictions this means a licensed fire protection engineer or a NICET-certified designer at the level required by state law. {note}
+### The Contractor shall confirm designer qualification requirements before assigning the design work, because in many jurisdictions this means a licensed fire protection engineer or a NICET-certified designer at the level required by state law.
## Closeout Submittals {toc}
…87 unchanged lines
```
−### Where the building's property insurance carrier or the Owner requires FM Global compliance, all components shall be FM-approved in addition to UL-listed.
−
### A component that is UL-listed may not be FM-approved, and the difference is consequential for insurance purposes. {note}
…7 unchanged lines
### NFPA 13 (2022 edition and later) recognizes nitrogen inerting as an alternative to galvanized pipe for corrosion control on dry-pipe systems. {note}
+### The Contractor shall provide one of three corrosion-mitigation approaches: galvanized steel pipe throughout the dry-pipe portion; nitrogen inerting of the dry-pipe system using a listed nitrogen generator that displaces oxygen; or both galvanized pipe and nitrogen inerting where the Owner's risk profile, insurance requirements, or service history warrants enhanced protection.
+
```datasheet
label: Corrosion Mitigation Approach
…7 unchanged lines
```
−### The Contractor shall provide one of three corrosion-mitigation approaches: galvanized steel pipe throughout the dry-pipe portion; nitrogen inerting of the dry-pipe system using a listed nitrogen generator that displaces oxygen; or both galvanized pipe and nitrogen inerting where the Owner's risk profile, insurance requirements, or service history warrants enhanced protection.
−
### Where nitrogen is used, the system shall be evacuated of air and refilled with nitrogen to the listed purity level — typically 98 percent nitrogen or greater at the sprinkler.
…6 unchanged lines
### Dry-pipe systems are designed to operate where the protected space drops below 40°F (4°C). {note}
−```datasheet
−label: Minimum Protected Space Temperature
−type: range
−unit: °F
−drawing_ref: true
−options:
− min: -40
− max: 40
− setpoints: [-40, -20, 0, 20, 32, 35, 40]
−default: 0
−```
+### The dry-pipe valve itself shall be installed in a heated enclosure or valve room maintained at not less than 40°F at all times.
```datasheet
…8 unchanged lines
```
−### The dry-pipe valve itself shall be installed in a heated enclosure or valve room maintained at not less than 40°F at all times.
−
### The valve trim, priming water (where used), and supply-side piping shall not be allowed to freeze.
### Where the protected space is a freezer, refrigerated room, or other deeply chilled environment, the designer shall account for the temperature differential at the valve-room-to-cold-space boundary and shall provide insulation, heat trace, or vapor barriers as required to prevent moisture migration into the dry-pipe piping during defrost cycles.
−## Maximum Working Pressure {toc}
−
−### The supply pressure to the dry-pipe valve also determines the required air pressure: a differential dry-pipe valve requires the air pressure to be maintained above a manufacturer-specified ratio of the water supply pressure (commonly 20 psi plus 25 percent of the maximum water supply pressure) to keep the clapper seated against false trips. {note}
−
```datasheet
−label: System Working Pressure
+label: Minimum Protected Space Temperature
type: range
−unit: psi
+unit: °F
drawing_ref: true
options:
− min: 40
− max: 250
− setpoints: [100, 125, 150, 175, 200, 250]
−default: 150
+ min: -40
+ max: 40
+ setpoints: [-40, -20, 0, 20, 32, 35, 40]
+default: 0
```
+## Maximum Working Pressure {toc}
+
+### The supply pressure to the dry-pipe valve also determines the required air pressure: a differential dry-pipe valve requires the air pressure to be maintained above a manufacturer-specified ratio of the water supply pressure (commonly 20 psi plus 25 percent of the maximum water supply pressure) to keep the clapper seated against false trips. {note}
+
+### The system air or nitrogen pressure shall be specified based on the water supply pressure and the dry-pipe valve manufacturer's required pressure ratio.
+
```datasheet
label: System Air or Nitrogen Pressure
…9 unchanged lines
### The system working pressure shall not exceed 175 psi at the dry-pipe valve unless the system is designed and the components are rated for a higher pressure.
+```datasheet
+label: System Working Pressure
+type: range
+unit: psi
+drawing_ref: true
+options:
+ min: 40
+ max: 250
+ setpoints: [40, 100, 125, 150, 175, 200, 250]
+default: 150
+```
+
### Where the water supply static pressure exceeds 175 psi, a pressure-reducing valve shall be provided on the supply to the dry-pipe valve.
…9 unchanged lines
### Ordinary Hazard Group 2 occupancies have higher rates of heat release, with representative dry-pipe applications including freezer warehouses (subject to NFPA 13 storage chapter cross-references), unheated repair garages, and certain industrial mezzanines. {note}
+### The hazard classification shall be assigned by the designer based on the occupancy descriptions in NFPA 13 Chapter 5 and shall be confirmed with the Owner and the AHJ prior to finalizing the hydraulic design.
+
```datasheet
label: Predominant Occupancy Hazard Classification
…9 unchanged lines
```
−### The hazard classification shall be assigned by the designer based on the occupancy descriptions in NFPA 13 Chapter 5 and shall be confirmed with the Owner and the AHJ prior to finalizing the hydraulic design.
−
### Extra Hazard occupancies are uncommon in dry-pipe applications because the high design density combined with the dry-pipe water delivery delay magnifies the risk. {note}
…5 unchanged lines
### Design density and design area shall be determined from NFPA 13 Table 19.2.3.1.1 for the applicable hazard classification, with the dry-pipe adjustment applied.
−### For example, an Ordinary Hazard Group 1 dry-pipe system designed at 0.15 gpm/sq ft uses a design area of 1,950 sq ft rather than the 1,500 sq ft used for the equivalent wet-pipe system. {note}
```datasheet
…8 unchanged lines
default: 0.15
```
+### For example, an Ordinary Hazard Group 1 dry-pipe system designed at 0.15 gpm/sq ft uses a design area of 1,950 sq ft rather than the 1,500 sq ft used for the equivalent wet-pipe system. {note}
+### NFPA 13 requires the design area for a dry-pipe system to be increased by 30 percent over the wet-pipe design area for the same hazard classification, in recognition of the delayed water delivery and the resulting larger fire size that may develop before water reaches the open sprinklers.
+
```datasheet
label: Design Area (dry-pipe, 30% increase applied)
…8 unchanged lines
```
−### NFPA 13 requires the design area for a dry-pipe system to be increased by 30 percent over the wet-pipe design area for the same hazard classification, in recognition of the delayed water delivery and the resulting larger fire size that may develop before water reaches the open sprinklers.
−
### The 30 percent dry-pipe area increase is mandatory and shall not be reduced by the designer based on engineering judgment alone.
…4 unchanged lines
### The hose stream allowance for a dry-pipe system is the same as for a wet-pipe system at the same hazard classification: 100 gpm for light hazard, 250 gpm for ordinary hazard, and 500 gpm for extra hazard. {note}
+### The hose stream allowance shall be specified to match the hazard classification of the sprinkler design.
+
```datasheet
label: Hose Stream Allowance
…29 unchanged lines
min: 20
max: 150
− setpoints: [40, 50, 60, 70, 80, 90, 100, 120, 150]
+ setpoints: [20, 40, 50, 60, 70, 80, 90, 100, 120, 150]
default: 70
```
…7 unchanged lines
min: 10
max: 130
− setpoints: [20, 30, 40, 50, 60, 70, 80, 100, 130]
+ setpoints: [10, 20, 30, 40, 50, 60, 70, 80, 100, 130]
default: 50
```
…17 unchanged lines
### Systems above 750 gallons commonly require a listed accelerator or other quick-opening device, nitrogen inerting (which allows the listed gas-displacement curve to be used), and/or subdivision into multiple dry-pipe systems served by separate dry-pipe valves. {note}
+### New dry-pipe systems shall not exceed 750 gallons (2,840 L) unless the designer demonstrates by calculation that water reaches the most remote inspector's test connection within 60 seconds of the test valve being opened.
+
```datasheet
label: Calculated System Volume
…4 unchanged lines
min: 50
max: 1500
− setpoints: [100, 250, 500, 750, 1000, 1250, 1500]
+ setpoints: [50, 100, 250, 500, 750, 1000, 1250, 1500]
default: 500
```
+### The designer shall calculate system volume early in the design process — before pipe routing is finalized — so that any volume mitigations (subdivision, accelerator, nitrogen) can be incorporated into the layout.
+
```datasheet
label: System Volume Mitigation Strategy
…9 unchanged lines
```
−### New dry-pipe systems shall not exceed 750 gallons (2,840 L) unless the designer demonstrates by calculation that water reaches the most remote inspector's test connection within 60 seconds of the test valve being opened.
−
−### The designer shall calculate system volume early in the design process — before pipe routing is finalized — so that any volume mitigations (subdivision, accelerator, nitrogen) can be incorporated into the layout.
−
### Adding volume mitigations after the fact is significantly more expensive than designing for them from the beginning. {note}
…3 unchanged lines
### The water delivery time depends on system volume, pipe diameter and arrangement, air pressure, water supply pressure, and the presence or absence of a quick-opening device. {note}
+### Water shall reach the inspector's test connection at the hydraulically most remote point of the system within 60 seconds of opening the inspector's test valve, measured from the time the test valve is fully open.
+
```datasheet
label: Water Delivery Time (calculated)
…7 unchanged lines
```
−### Water shall reach the inspector's test connection at the hydraulically most remote point of the system within 60 seconds of opening the inspector's test valve, measured from the time the test valve is fully open.
−
### For systems exceeding 750 gallons, the designer shall submit a water delivery time calculation using one of the accepted methods: the NFPA 13 spreadsheet-based volume/pressure method; a manufacturer's accelerator-specific delivery time calculation; or a computational fluid dynamics analysis where the geometry is too complex for tabular methods.
…12 unchanged lines
### Low-differential valves are increasingly common because they pair well with nitrogen inerting (where nitrogen pressure is held closer to water pressure for a tighter operational margin). {note}
+### The dry-pipe valve type shall be specified as a differential or low-differential valve, considering compatibility with nitrogen inerting.
+
```datasheet
label: Dry-Pipe Valve Type
…5 unchanged lines
```
+### The dry-pipe valve size shall be specified to match the hydraulic design of the system.
+
```datasheet
label: Dry-Pipe Valve Size
…11 unchanged lines
```
+### The dry-pipe valve body and trim material shall be specified based on the service environment of the valve location.
+
```datasheet
label: Dry-Pipe Valve Body Material
…58 unchanged lines
### The most common quick-opening device (QOD) is an accelerator, a listed device installed at the dry-pipe valve that detects the rate of air pressure drop in the system and rapidly equalizes the differential pressure across the clapper, tripping the valve sooner than it would have tripped on its own. {note}
+### A quick-opening device shall be provided where required by NFPA 13 — that is, where the calculated water delivery time without a QOD exceeds 60 seconds for a 750-gallon system, or where the Owner requires faster water delivery for property protection.
+
```datasheet
label: Quick-Opening Device
…7 unchanged lines
```
−### A quick-opening device shall be provided where required by NFPA 13 — that is, where the calculated water delivery time without a QOD exceeds 60 seconds for a 750-gallon system, or where the Owner requires faster water delivery for property protection.
−
−### Accelerators shall be listed and, where FM compliance is required, approved to FM 2011.
−
### The accelerator shall be installed strictly per the dry-pipe valve manufacturer's instructions.
…10 unchanged lines
### The dedicated compressor arrangement is preferred for new construction because it isolates the dry-pipe system from plant air contamination and pressure fluctuations. {note}
+### Where the supervisory gas is air, an air compressor shall be provided to maintain the system at the required air pressure.
+
```datasheet
label: Air Supply Type
…7 unchanged lines
```
+### The compressor shall be capable of restoring the system from atmospheric pressure to the required operating pressure within 30 minutes for systems up to 750 gallons, and within 60 minutes for larger systems, as permitted by NFPA 13.
+
```datasheet
label: Air Compressor Restoration Time Requirement
…7 unchanged lines
```
+### The compressor shall be sized by the air maintenance device manufacturer's recommendation based on system volume, expected leakage rate, and required restoration time.
+
```datasheet
label: Air Compressor Sizing Basis
…6 unchanged lines
```
−### Where the supervisory gas is air, an air compressor shall be provided to maintain the system at the required air pressure.
−
−### The compressor shall be capable of restoring the system from atmospheric pressure to the required operating pressure within 30 minutes for systems up to 750 gallons, and within 60 minutes for larger systems, as permitted by NFPA 13.
−
−### The compressor shall be sized by the air maintenance device manufacturer's recommendation based on system volume, expected leakage rate, and required restoration time.
−
### The air maintenance device shall be listed and, where FM compliance is required, approved to FM 2024.
…8 unchanged lines
### Nitrogen generators are increasingly the default specification for new dry-pipe systems in cold-storage warehouses, healthcare facilities, and other long-life or critical assets. {note}
+### Where a nitrogen generator is provided, the purge cycle method shall be specified to maintain the required nitrogen purity at the most remote sprinkler.
+
```datasheet
+label: Nitrogen Generator Purge Cycle
+type: radio
+options:
+ - "Continuous purge from generator to maintain purity"
+ - "Periodic timed purge at automatic vent"
+ - "Initial purge only at commissioning"
+default: "Periodic timed purge at automatic vent"
+```
+
+### Where the supervisory gas is nitrogen, a listed nitrogen generator shall be provided.
+
+```datasheet
label: Nitrogen Generator Type
type: radio
…5 unchanged lines
```
+### The generator shall produce a gas of at least 98 percent nitrogen at the dry-pipe valve.
+
+### The system shall be purged of residual air during commissioning so that the nitrogen purity at the most remote sprinkler also reaches the listed level.
+
```datasheet
label: Nitrogen Purity at Sprinkler
…3 unchanged lines
min: 90
max: 99
− setpoints: [95, 98, 99]
+ setpoints: [90, 95, 98, 99]
default: 98
```
−```datasheet
−label: Nitrogen Generator Purge Cycle
−type: radio
−options:
− - "Continuous purge from generator to maintain purity"
− - "Periodic timed purge at automatic vent"
− - "Initial purge only at commissioning"
−default: "Periodic timed purge at automatic vent"
−```
−
−### Where the supervisory gas is nitrogen, a listed nitrogen generator shall be provided.
−
−### The generator shall produce a gas of at least 98 percent nitrogen at the dry-pipe valve.
−
−### The system shall be purged of residual air during commissioning so that the nitrogen purity at the most remote sprinkler also reaches the listed level.
−
## Air Leakage Limit {toc}
### A leaky system masks itself with frequent compressor cycling that conceals the underlying defect; the air-leakage test is the only reliable way to verify joint integrity in an air-pressurized system. {note}
+### NFPA 13 requires that the system not lose more than 1.5 psi of air or nitrogen pressure over 24 hours after the system is brought to operating pressure and isolated from the supply.
+
```datasheet
label: Air Leakage Test Limit
…5 unchanged lines
```
−### NFPA 13 requires that the system not lose more than 1.5 psi of air or nitrogen pressure over 24 hours after the system is brought to operating pressure and isolated from the supply.
−
### The Contractor shall conduct an air-leakage test at acceptance and shall document the result.
…7 unchanged lines
### For dry-pipe systems the galvanized variant is strongly preferred over the black variant unless the system is also nitrogen-inerted, because internal corrosion in cycled wet-dry environments is significantly more aggressive than in continuously wet systems. {note}
+### Steel pipe shall conform to ASTM A795 or ASTM A53, as applicable.
+
```datasheet
label: Steel Pipe Standard
…7 unchanged lines
```
+### Steel pipe used in dry-pipe systems shall be Schedule 40 for threaded joints in sizes 3 in. and smaller, and shall be Schedule 10 (listed for dry-system service) or Schedule 40 for grooved or welded joints.
+
```datasheet
label: Steel Pipe Schedule
…6 unchanged lines
```
−### Steel pipe shall conform to ASTM A795 or ASTM A53, as applicable.
−
−### Steel pipe used in dry-pipe systems shall be Schedule 40 for threaded joints in sizes 3 in. and smaller, and shall be Schedule 10 (listed for dry-system service) or Schedule 40 for grooved or welded joints.
−
### The Contractor shall confirm that the specific pipe product carries the dry-system listing from the manufacturer, because not all Schedule 10 pipe is listed for dry-pipe service.
…70 unchanged lines
### A dry-pendent sprinkler is a specialized sprinkler with an extended barrel and an internal seal at the inlet, allowing the sprinkler to be installed pendent below a ceiling while keeping the supply piping above the ceiling in the heated space, and the barrel running through the unheated cavity. {note}
+### All sprinklers shall be listed to UL 199 and shall be installed in accordance with their listing and the installation requirements of NFPA 13.
+
+### Sprinklers shall not be modified in any way, including bending of the deflector, painting, or application of any coating, after leaving the factory.
+
+### Factory-applied coatings provided by the manufacturer for corrosive environments are permitted; field-applied paint or coatings over sprinklers are prohibited.
+
+### Upright sprinklers shall be the default for exposed dry-pipe piping in mechanical rooms, parking garages, and warehouse spaces because their orientation prevents water from collecting in the sprinkler body and freezing.
+
```datasheet
label: Sprinkler Orientation
…7 unchanged lines
```
+### Standard pendent sprinklers shall not be installed on dry-pipe systems because residual water at the sprinkler will freeze and damage the sprinkler.
+
+### Where pendent installation is required for architectural or coverage reasons, listed dry-pendent (or dry-sidewall) sprinklers shall be used.
+
+### The dry-pendent or dry-sidewall barrel length shall be sized so that the inlet seal sits in the warm side of the insulated separation; consult the manufacturer's barrel length tables.
+
```datasheet
label: Dry-Pendent / Dry-Sidewall Barrel Length
…13 unchanged lines
```
−### All sprinklers shall be listed to UL 199 and shall be installed in accordance with their listing and the installation requirements of NFPA 13.
−
−### Sprinklers shall not be modified in any way, including bending of the deflector, painting, or application of any coating, after leaving the factory.
−
−### Factory-applied coatings provided by the manufacturer for corrosive environments are permitted; field-applied paint or coatings over sprinklers are prohibited.
−
−### Upright sprinklers shall be the default for exposed dry-pipe piping in mechanical rooms, parking garages, and warehouse spaces because their orientation prevents water from collecting in the sprinkler body and freezing.
−
−### Standard pendent sprinklers shall not be installed on dry-pipe systems because residual water at the sprinkler will freeze and damage the sprinkler.
−
−### Where pendent installation is required for architectural or coverage reasons, listed dry-pendent (or dry-sidewall) sprinklers shall be used.
−
−### The dry-pendent or dry-sidewall barrel length shall be sized so that the inlet seal sits in the warm side of the insulated separation; consult the manufacturer's barrel length tables.
−
## Thermal Response {toc}
### The NFPA 13 design density and area tables for dry-pipe systems are based on standard response sprinklers; mixing quick response sprinklers with a standard-response design produces unpredictable performance. {note}
+### Sprinklers are classified by thermal response as standard response or quick response based on the response time index (RTI) of the thermal element. {note}
+
+### Quick response sprinklers are not required in dry-pipe systems and shall not be used in dry-pipe systems unless specifically permitted by the listing and the hydraulic design accounts for the response timing.
+
```datasheet
label: Sprinkler Thermal Response
…5 unchanged lines
```
−### Sprinklers are classified by thermal response as standard response or quick response based on the response time index (RTI) of the thermal element. {note}
−
−### Quick response sprinklers are not required in dry-pipe systems and shall not be used in dry-pipe systems unless specifically permitted by the listing and the hydraulic design accounts for the response timing.
−
## Temperature Ratings {toc}
…24 unchanged lines
### The K-5.6 sprinkler is the most widely used standard commercial sprinkler in dry-pipe applications. {note}
+### Larger K-factors may be selected for dry-pipe applications where the design density and area combine to require a higher flow per sprinkler than K-5.6 can deliver at acceptable pressures.
+
```datasheet
label: Sprinkler K-Factor
…8 unchanged lines
```
−### Larger K-factors may be selected for dry-pipe applications where the design density and area combine to require a higher flow per sprinkler than K-5.6 can deliver at acceptable pressures.
−
## Finish {toc}
…38 unchanged lines
### A dry-pipe system with sagging pipe or insufficient pitch will retain residual water at low spots, where the water freezes during the next cold cycle, ruptures the pipe, and floods the building when the rupture thaws. {note}
+### Dry-pipe system piping shall be pitched to drain back to the dry-pipe valve or to auxiliary drains (drum drips) at low points.
+
+### NFPA 13 requires minimum pitch of 1/2 in. per 10 ft for branch lines and 1/4 in. per 10 ft for mains in steel-pipe systems.
+
```datasheet
label: Minimum Branch Line Pitch
…18 unchanged lines
```
−### Dry-pipe system piping shall be pitched to drain back to the dry-pipe valve or to auxiliary drains (drum drips) at low points.
−
−### NFPA 13 requires minimum pitch of 1/2 in. per 10 ft for branch lines and 1/4 in. per 10 ft for mains in steel-pipe systems.
−
### The Contractor shall verify pitch at every section of pipe during installation using a level.
…5 unchanged lines
### To drain, the operator closes the upper valve, opens the lower valve to discharge collected water, closes the lower valve, and opens the upper valve again to restore system continuity. {note}
+### Auxiliary drains, commonly called drum drips, shall be provided at every trapped section of pipe where water cannot drain back to the main drain by gravity.
+
```datasheet
label: Auxiliary Drain (Drum Drip) Configuration
…6 unchanged lines
```
+### Drum drips shall be located so that they can be reached for routine drainage.
+
+### The Contractor shall coordinate drum drip locations with the architect to provide access doors or accessible plenums at every drum drip.
+
```datasheet
label: Drum Drip Access Provisions
…7 unchanged lines
```
−### Auxiliary drains, commonly called drum drips, shall be provided at every trapped section of pipe where water cannot drain back to the main drain by gravity.
−
−### Drum drips shall be located so that they can be reached for routine drainage.
−
−### The Contractor shall coordinate drum drip locations with the architect to provide access doors or accessible plenums at every drum drip.
−
### Each drum drip shall be identified with a permanent sign indicating its location relative to the dry-pipe valve and the seasonal drainage schedule.
…65 unchanged lines
### The "DRY" designation alerts the responding fire department to the delayed water delivery of a dry-pipe system, which affects how they will pressurize the FDC during operations. {note}
+### The FDC shall be identified with a sign reading "AUTO SPKR — DRY" in letters not smaller than 1 in. in height, in accordance with NFPA 13.
+
```datasheet
label: FDC Identification Sign
…5 unchanged lines
```
−### The FDC shall be identified with a sign reading "AUTO SPKR — DRY" in letters not smaller than 1 in. in height, in accordance with NFPA 13.
−
### Where the building has multiple FDCs serving separate sprinkler systems (some wet, some dry), each FDC shall identify the zone and the system type.
…77 unchanged lines
### Seismic design for dry-pipe systems follows the same provisions as for wet-pipe systems with one important addition: dry-pipe systems are more sensitive to joint failure during seismic events because the resulting loss of air pressure trips the valve and floods the system. {note}
+### Where the building is located in a Seismic Design Category (SDC) C, D, E, or F as defined by ASCE 7 and the IBC, lateral and longitudinal seismic bracing shall be provided for the sprinkler system in accordance with NFPA 13 Chapter 18.
+
```datasheet
label: Seismic Bracing Required
…20 unchanged lines
```
+### Flexible couplings at the prescribed locations are essential.
+
```datasheet
label: Flexible Couplings at Seismic Brace Locations
…6 unchanged lines
```
−### Where the building is located in a Seismic Design Category (SDC) C, D, E, or F as defined by ASCE 7 and the IBC, lateral and longitudinal seismic bracing shall be provided for the sprinkler system in accordance with NFPA 13 Chapter 18.
−
−### Flexible couplings at the prescribed locations are essential.
−
# Installation {toc}
…123 unchanged lines
### The trip test confirms that the valve operates as listed and that the calculated water delivery time is achieved in practice. {note}
+### The dry-pipe valve shall be trip-tested by opening the inspector's test valve at the most remote point of the system and timing the interval until water discharges from the inspector's test connection.
+
+### Trip tests shall be performed both with the quick-opening device (where installed) in service and, where required by the AHJ, with the QOD bypassed.
+
+### The water delivery time at the trip test shall not exceed 60 seconds from opening of the inspector's test valve to water discharge, in accordance with NFPA 13.
+
```datasheet
label: Maximum Water Delivery Time at Trip Test
…5 unchanged lines
```
−### The dry-pipe valve shall be trip-tested by opening the inspector's test valve at the most remote point of the system and timing the interval until water discharges from the inspector's test connection.
−
−### Trip tests shall be performed both with the quick-opening device (where installed) in service and, where required by the AHJ, with the QOD bypassed.
−
−### The water delivery time at the trip test shall not exceed 60 seconds from opening of the inspector's test valve to water discharge, in accordance with NFPA 13.
−
### The trip test result shall be recorded on the Contractor's Material and Test Certificate.
…18 unchanged lines
min: 20
max: 200
− setpoints: [40, 50, 60, 70, 80, 100, 120, 150, 175, 200]
+ setpoints: [20, 40, 50, 60, 70, 80, 100, 120, 150, 175, 200]
default: 70
```
…7 unchanged lines
min: 10
max: 180
− setpoints: [20, 30, 40, 50, 60, 70, 80, 100, 120, 150]
+ setpoints: [10, 20, 30, 40, 50, 60, 70, 80, 100, 120, 150, 180]
default: 50
```
…25 unchanged lines
## NFPA 25 establishes mandatory intervals for inspecting system components, testing alarm devices, conducting main drain tests, performing the dry-pipe valve trip test, and servicing the air supply. {note}
+## The dry-pipe system shall be inspected, tested, and maintained throughout the life of the building in accordance with NFPA 25, current adopted edition.
+
+## Specific NFPA 25 requirements for dry-pipe systems shall include weekly or monthly inspection of the air or nitrogen pressure gauge and the dry-pipe valve enclosure heating; quarterly testing of waterflow and supervisory alarm devices; quarterly testing of low-pressure supervisory; annual full-flow trip test of the dry-pipe valve with the quick-opening device in service (and a separate test with the QOD bypassed in some jurisdictions); seasonal draining of every auxiliary drain (drum drip) before the first freeze and after every trip; 3-year internal inspection of the dry-pipe valve; and 5-year internal pipe assessment to check for obstruction, corrosion, and microbiological growth.
+
+## Dry-pipe systems shall be drained, dried, and refilled with fresh supervisory gas as part of the 3-year internal inspection.
+
+## The Owner shall maintain a service agreement with a qualified fire protection service contractor to perform NFPA 25 inspections and tests at the required intervals.
+
```datasheet
label: NFPA 25 Service Agreement
…5 unchanged lines
```
−## The dry-pipe system shall be inspected, tested, and maintained throughout the life of the building in accordance with NFPA 25, current adopted edition.
−
−## Specific NFPA 25 requirements for dry-pipe systems shall include weekly or monthly inspection of the air or nitrogen pressure gauge and the dry-pipe valve enclosure heating; quarterly testing of waterflow and supervisory alarm devices; quarterly testing of low-pressure supervisory; annual full-flow trip test of the dry-pipe valve with the quick-opening device in service (and a separate test with the QOD bypassed in some jurisdictions); seasonal draining of every auxiliary drain (drum drip) before the first freeze and after every trip; 3-year internal inspection of the dry-pipe valve; and 5-year internal pipe assessment to check for obstruction, corrosion, and microbiological growth.
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−## Dry-pipe systems shall be drained, dried, and refilled with fresh supervisory gas as part of the 3-year internal inspection.
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−## The Owner shall maintain a service agreement with a qualified fire protection service contractor to perform NFPA 25 inspections and tests at the required intervals.
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## Owner-performed inspections are permitted for certain visual tasks, but trip tests, internal valve inspections, and 5-year internal pipe assessments shall be performed by qualified service personnel.
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## The Contractor shall maintain the ability to restore impaired systems to full service within the time limits required by the AHJ and the Owner's insurance carrier.