1 Scope

NOTE This specification establishes the foundational, cross-cutting mechanical requirements that apply uniformly to all HVAC and mechanical work on a project, serving as the umbrella mechanical common-work standard under which every subsequent mechanical section is written. (1.1)

NOTE It declares the project-wide governing code basis, basis-of-design fluid and temperature assumptions, common product requirements, general installation workmanship, and field execution standards that are too general to belong to any single equipment section, so they are stated once and inherited rather than restated and contradicted. (1.2)

NOTE The scope encompasses general code compliance, common motor requirements for HVAC equipment, general-duty valves for HVAC piping, expansion fittings and loops, pipe sleeves and sleeve seals, meters and gages, equipment supports and seismic restraint thresholds, rated penetration firestopping, division-wide submittals and quality assurance, field startup and acceptance testing, and warranty. (1.3)

NOTE The basis-of-design framing is central to this section: it records what the mechanical Engineer of Record has assumed about the building's fluids, design supply temperatures, and system operating pressure before any equipment is purchased, so that downstream sections governing boilers, chillers, coils, and heat exchangers all work from a single declared baseline rather than each assuming its own. (1.4)

NOTE This standard is prescriptive but deliberately non-duplicative, and it does not cover several adjacent topics that are governed by their own standards. The following boundaries apply: pipe hangers, trapeze assemblies, and seismic bracing of piping and ductwork beyond threshold setting belong to Hangers And SupportsHangers and Supports for Mechanical Piping and EquipmentResolves to the current edition.sync/hangers-and-supports; thermal insulation belongs to Mechanical InsulationMechanical InsulationResolves to the current edition.sync/mechanical-insulation; vibration isolation bases, inertia pads, and snubbers belong to Vibration Isolation And Seismic RestraintVibration Isolation and Seismic RestraintResolves to the current edition.sync/vibration-isolation-and-seismic-restraint; identification tags and color banding belong to Mechanical IdentificationMechanical IdentificationResolves to the current edition.sync/mechanical-identification; hydronic piping systems and specialties beyond common valves belong to Hydronic PipingHydronic PipingResolves to the current edition.sync/hydronic-piping and system flushing to Hydronic Cleaning And FlushingHydronic System Cleaning and FlushingResolves to the current edition.sync/hydronic-cleaning-and-flushing; testing, adjusting, and balancing belongs to Testing Adjusting And BalancingTesting, Adjusting, and Balancing for HVACResolves to the current edition.sync/testing-adjusting-and-balancing; and variable frequency drives belong to HVAC Variable Frequency DrivesHVAC Variable Frequency DrivesResolves to the current edition.sync/hvac-variable-frequency-drives. (1.5)

NOTE Three additional scope boundaries apply beyond the HVAC-adjacency cross-references above: sheet-metal duct construction is governed by SMACNA and belongs to the air-distribution sections; refrigerant piping is governed by ASHRAE 15 and ASME B31.5 and belongs to the refrigeration sections; and electrical power wiring to mechanical equipment, including motor branch circuits, disconnects, and overcurrent protection, is governed by Common Work Results ElectricalCommon Work Results for ElectricalResolves to the current edition.sync/common-work-results-electrical and the National Electrical Code — this section governs only the mechanical equipment and its coordination interface to that wiring. (1.6)

2 Referenced Standards

2.1 Equipment, materials, and installation shall comply with the latest adopted edition of each of the following unless a specific edition is cited or the Authority Having Jurisdiction has adopted a different edition.

2.2 Where the contract documents, the adopted building code, or a referenced standard conflict, the more stringent requirement shall govern unless the Engineer of Record directs otherwise in writing.

Standard	Title
IMC	International Mechanical Code
IBC	International Building Code (Chapter 28, Section 714)
ASME B31.9	Building Services Piping
ASME B16.5	Pipe Flanges and Flanged Fittings, NPS 1/2 through NPS 24
ASHRAE 90.1	Energy Standard for Sites and Buildings Except Low-Rise Residential Buildings
NFPA 70 (NEC)	National Electrical Code (Articles 430 and 440)
NEMA MG 1	Motors and Generators
ASTM A53/A53M	Pipe, Steel, Black and Hot-Dipped, Zinc-Coated, Welded and Seamless
ASTM B88	Seamless Copper Water Tube
MSS SP-58	Pipe Hangers and Supports — Materials, Design, Manufacture and Product Marking
SMACNA	HVAC Duct Construction Standards — Metal and Flexible
ASCE 7	Minimum Design Loads and Associated Criteria for Buildings and Other Structures (Chapter 13)
ASTM E814	Test Method for Fire Tests of Penetration Firestop Systems
ASHRAE Handbook	HVAC Systems and Equipment

3 Basis of Design

NOTE This section records the fluids, design temperatures, and operating pressures the mechanical Engineer of Record has assumed for the facility. Every downstream mechanical section, equipment submittal, and pump or coil schedule depends on these values being declared once and held uniform; when they are omitted, each section silently assumes its own design conditions and the conflicts surface only at submittal review or, worse, at startup. (3.1)

3.2 Governing Code Edition

3.2.1 The mechanical installation shall comply with the edition of the International Mechanical Code adopted by the Authority Having Jurisdiction at the project location, together with all state and local amendments in force.

Governing Mechanical Code Editionradio

● IMC 2021

○ IMC 2018

○ IMC 2015

○ AHJ-adopted edition to be confirmed before rough-in

3.2.2 Pressure piping shall comply with the edition of ASME B31.9 (Building Services Piping) adopted or referenced by the Authority Having Jurisdiction.

Governing Pressure Piping Code (ASME B31.9 Edition)radio

○ ASME B31.9-2025

● ASME B31.9-2020

○ ASME B31.9-2017

3.2.3 The Contractor shall confirm the adopted IMC and ASME B31.9 editions and applicable amendments with the Authority Having Jurisdiction before commencing rough-in, and shall notify the Engineer of Record in writing of any amendment that conflicts with the contract documents.

3.2.4 The edition assumed in design shall be reconciled against the locally adopted edition before specifications are issued for construction and shall not be presumed to be the most recent publication.

NOTE Many jurisdictions lag the published model codes by one or more cycles; confirming the adopted edition before specifications are finalized prevents code conflicts from surfacing during permit review. (3.2.5)

3.3 Design Fluids and Temperatures

3.3.1 The basis-of-design fluid type and design supply and return temperatures of each hydronic and steam system shall be declared here and shall govern all downstream sections including boilers, chillers, coils, heat exchangers, and pumps.

Hot Water Heating Supply / Return Temperatureradio

○ 180 / 160

● 160 / 130

○ 140 / 120

○ 120 / 100 (condensing / low-temperature)

Chilled Water Supply / Return Temperatureradio

● 44 / 56

○ 42 / 58

○ 40 / 54

Hydronic System Fluidradio

● Water

○ Propylene glycol solution

○ Ethylene glycol solution

3.3.2 Where a system uses a glycol solution rather than water, the glycol type and volumetric concentration shall be declared so that downstream sections can apply the correct freeze protection, derating, and fluid properties.

Glycol Concentration (where glycol is used)range

%

2050

Per drawings (deferred by default)

NOTE Declaring design supply water temperatures once prevents the common coordination failure in which the boiler section sizes for one supply temperature while the coil section selects for another, and the mismatch is not caught until equipment submittals arrive. (3.3.3)

3.4 System Operating Pressure

3.4.1 The design working pressure of each piping system shall be declared in the basis of design before any valve, gage, or pressure-rated component is procured, and shall govern the pressure class of all components in that system.

Hydronic System Design Working Pressurerange

PSI

60250

Default: 125 PSI

3.4.2 All valves, fittings, flanges, and specialties in a system shall carry a pressure-temperature rating equal to or greater than the system design working pressure at the system design temperature.

3.4.3 Systems whose design pressure approaches the ASME B31.9 scope limit of 250 PSI shall be reviewed against the B31.9 applicability criteria before the code basis is fixed.

NOTE Building services piping under ASME B31.9 is limited to water systems not exceeding 250 PSI; systems near this threshold may fall outside B31.9 scope and require a different pressure piping code to govern the installation. (3.4.4)

4 Submittals

4.1 Action Submittals

4.1.1 The Contractor shall submit the following for review before procurement and installation, organized by system and clearly identifying the basis-of-design values from this section that each submittal relies upon:

Product data for each HVAC motor, including horsepower, voltage and phase, enclosure type, NEMA efficiency class, service factor, insulation class, and inverter-duty rating where VFD-driven
Product data for each general-duty valve type, including body and trim material, end connections, and pressure-temperature rating
Product data for expansion fittings, loops, and anchors, including movement capacity and rated working conditions
Product data for pipe sleeves and sleeve seals, including modular seal model selection by sleeve and pipe size
Product data for meters and gages, including pressure gage range, thermometer range and stem length, thermowells, and test plugs
Firestop system data for each rated penetration condition, identifying the listed system number and hourly rating
Equipment support and seismic restraint data and, where required by the seismic design category, engineered anchorage and bracing details
Field startup and acceptance test plan, including pressure-test method, hold time, and motor rotation verification procedure

Action Submittals Requiredcheckbox

☑ HVAC motor product data with efficiency, enclosure, and inverter-duty rating

☐ General-duty valve product data by type and pressure rating

☐ Expansion fitting, loop, and anchor product data

☐ Pipe sleeve and sleeve-seal product data

☐ Meters and gages product data including thermowells and test plugs

☐ Firestop system data with listed system numbers

☐ Equipment support and seismic restraint details

☐ Field startup and acceptance test plan

4.2 Closeout Submittals

4.2.1 At substantial completion and before final acceptance, the Contractor shall provide the following:

Field pressure-test reports for each system, signed by the responsible person, with test medium, test pressure, hold time, measured pressure drop, ambient temperature, acceptance criteria, and pass/fail determination
Motor rotation and operational-check records confirming verification against equipment manufacturer rotation arrows
Completed firestop installation schedule confirming the listed system installed at each rated penetration
Operation and maintenance data for valves, meters, gages, and other serviceable common components
Warranty documentation for products and equipment carrying a manufacturer warranty

Required Closeout Submittalscheckbox

☑ Field pressure-test reports

☑ Motor rotation and operational-check records

☐ Firestop installation schedule

☐ Operation and maintenance data

☑ Warranty documentation

4.3 Informational Submittals

4.3.1 The Contractor shall submit the following for the record:

Written confirmation of the AHJ-adopted IMC and ASME B31.9 editions and applicable local amendments
Qualification statements for welders and the welding procedure specifications where pressure piping is welded
Qualification statement for the seismic-restraint design professional where seismic restraint is delegated-design

Informational Submittals Requiredcheckbox

☑ AHJ-adopted IMC and ASME B31.9 edition confirmation

☐ Welder and welding procedure qualifications

☐ Seismic-restraint designer qualifications

5 Quality Assurance

5.1 Installer Qualifications

5.1.1 All mechanical work shall be performed by qualified mechanics employed by a licensed mechanical contractor with demonstrated experience on commercial, institutional, or industrial HVAC projects of comparable scope.

5.1.2 Welding of pressure piping shall be performed only by welders qualified under ASME Section IX to a welding procedure specification applicable to the materials and joint configurations on the project.

5.1.3 Personnel performing field pressure and acceptance testing shall be qualified in the use of the test instruments and shall follow the procedures of ASME B31.9.

5.2 Listing and Code Compliance

5.2.1 All mechanical equipment, valves, and components shall be listed or labeled where a listing exists for the product category and shall be rated for the service in which they are installed.

5.2.2 General-duty valves shall carry permanent markings of manufacturer, size, pressure class, and body material, cast or stamped on the body.

5.2.3 Equipment and components shall not be installed where the system design pressure or temperature exceeds the component's marked pressure-temperature rating.

5.3 Single Source and Standardization

5.3.1 To the greatest extent practicable, each general-duty valve type shall be furnished by a single manufacturer across the project so that trim, operators, and repair parts are interchangeable.

5.3.2 Standardizing a valve type to one manufacturer reduces the spare-parts inventory the owner must carry and avoids field confusion between visually similar valves with different internal trim.

6 Common Motor Requirements

NOTE This section governs the integral HVAC motors furnished as part of mechanical equipment such as fans, pumps, and air handlers, establishing the ratings common to all of them so that each equipment section need not restate them. (6.1)

NOTE Electrical power wiring, branch-circuit protection, and disconnects for these motors are governed by Common Work Results ElectricalCommon Work Results for ElectricalResolves to the current edition.sync/common-work-results-electrical and the NEC; this section governs only the motor as a mechanical component and its rating. (6.2)

6.3 Motor Ratings

6.3.1 Motors 1/2 horsepower and smaller shall be permitted to be single-phase, 115V or 208–230V.

Single-Phase Fractional Motor Voltage (≤ 1/2 hp)radio

● 115V, 1Φ, 60 Hz

○ 208–230V, 1Φ, 60 Hz

6.3.2 Motors larger than 1/2 horsepower shall be three-phase at the project basis-of-design voltage.

6.3.3 Three-phase motors shall be selected for the declared building distribution voltage, and motors 5 horsepower and larger on a 480V system shall be rated 460V.

Three-Phase Motor Nameplate Voltageradio

● 460V, 3Φ, 60 Hz

○ 208V, 3Φ, 60 Hz

○ 230V, 3Φ, 60 Hz

○ 575V, 3Φ, 60 Hz (Canada)

6.3.4 The motor nameplate voltage shall be a single declared value, not a slash-rated range left to the installer.

6.3.5 The actual system voltage shall be specified on the motor schedule so that feeders are sized for the operating voltage and not defaulted to the lowest value in a multi-voltage range.

NOTE Leaving the wiring voltage unspecified on a slash-rated motor invites the contractor to default to the lowest value in the range, which can overload feeders and foreclose future voltage upgrades. (6.3.6)

6.4 Efficiency

6.4.1 Polyphase motors 1 horsepower and larger shall meet the minimum nominal full-load efficiency of NEMA Premium (IE3) per NEMA MG 1, in compliance with ASHRAE 90.1.

Polyphase Motor Efficiency Class (≥ 1 hp)radio

● NEMA Premium (IE3)

NOTE Specifying standard-efficiency motors at 1 horsepower and larger is a code violation in jurisdictions that have adopted ASHRAE 90.1; NEMA Premium is the minimum for new HVAC installations. (6.4.2)

6.5 Enclosure

6.5.1 Motors installed in clean, dry, indoor mechanical rooms with no washdown or high-humidity exposure shall be permitted to be open drip-proof.

6.5.2 All other motors shall be totally enclosed fan-cooled.

Motor Enclosure Typeradio

● TEFC (totally enclosed fan-cooled)

○ ODP (open drip-proof)

○ TEFC with explosion-proof rating for classified areas

6.5.3 Motors in spaces classified by the mechanical Engineer as wet or damp locations shall be totally enclosed fan-cooled at minimum, and shall not be open drip-proof.

NOTE Open drip-proof enclosures are not suitable for washdown or high-humidity spaces; defaulting to ODP in any space that may be wet leads to premature motor failure, so TEFC is the minimum where the space classification is anything other than clean and dry. (6.5.4)

6.6 Service Factor and Insulation

6.6.1 General-purpose motors not driven by a variable frequency drive shall have a service factor of not less than 1.15.

6.6.2 General-purpose motors not driven by a variable frequency drive shall have Class F insulation rated for 155°C.

Insulation Classradio

● Class F (155°C)

○ Class H (180°C) for high-ambient or inverter-duty service

6.6.3 Motors intended for operation on a variable frequency drive shall be rated inverter-duty per NEMA MG 1 Part 31, with insulation system suitable for the drive switching frequency.

Inverter-Duty Rating (for VFD-driven motors)radio

● NEMA MG 1 Part 31 inverter-duty required

○ Not VFD-driven; standard general-purpose

NOTE Standard motors driven by a VFD can fail prematurely from voltage stress above certain switching frequencies; specifying NEMA MG 1 Part 31 inverter-duty rating for all VFD-driven motors prevents this failure mode. (6.6.4)

7 General-Duty Valves for HVAC Piping

NOTE This section governs the manual isolation, balancing, and check valves common to HVAC piping. Control valves, automatic balancing valves, and system-specific specialties are governed by their respective system sections. (7.1)

NOTE General-duty valves are selected primarily by pipe size, service, and the function the valve performs, and the project benefits from a small, standardized set rather than a different valve at every connection. (7.2)

7.3 Valve Selection by Size

7.3.1 Isolation valves 2 inches and smaller shall be full-port bronze ball valves, and isolation valves 2-1/2 inches and larger shall be lug- or wafer-pattern butterfly valves with ductile-iron body, EPDM seat, and stainless disc.

Isolation Valve Type, 2 in. and Smallerradio

● Full-port bronze ball valve, 600 WOG / 150 SWP

○ Bronze gate valve, 125 lb

Isolation Valve Type, 2-1/2 in. and Largerradio

● Lug-pattern butterfly, ductile iron / EPDM / stainless disc, 200 PSI

○ Wafer-pattern butterfly, ductile iron / EPDM / stainless disc, 200 PSI

○ Iron gate valve, 125 lb (steam service)

7.3.2 Butterfly valves 6 inches and smaller shall be furnished with lever handles, and butterfly valves 8 inches and larger shall be furnished with gear operators.

7.3.3 Cast or ductile iron shall be used for valve bodies above 2 inches; bronze bodies are not permitted at 2-1/2 inches and larger.

NOTE Bronze valves are commonly stocked only through 2 inches; specifying bronze above that size results in substitution requests or long-lead special orders. (7.3.4)

7.4 Valve Function

7.4.1 Throttling and balancing service shall use globe-pattern valves: bronze through 2 inches and iron 2-1/2 inches and larger.

7.4.2 Steam and condensate isolation shall use gate valves rather than ball or butterfly valves where the gate pattern is preferred for full-bore flow and tight shutoff.

7.4.3 Check valves shall be selected for the service and orientation, with silent spring-loaded checks at pump discharge to limit water hammer on pump shutdown.

Throttling / Balancing Valve Typeradio

● Globe valve, bronze ≤ 2 in. / iron ≥ 2-1/2 in.

○ Calibrated balancing valve

Pump Discharge Check Valve Typeradio

● Silent spring-loaded wafer check

○ Swing check

7.5 Valve Pressure Class

7.5.1 Each valve shall carry a pressure-temperature rating equal to or greater than the system design working pressure declared in the basis of design at the system design temperature.

7.5.2 Where the system design pressure exceeds the standard 150 SWP / 200 CWP rating of common bronze and ductile-iron valves, the higher-class valve body and trim shall be specified and reconciled against flange ratings per ASME B16.5.

8 Expansion Fittings and Loops

8.1 Thermal growth and contraction of HVAC piping must be accommodated so that the movement is not transmitted to equipment connections, branch takeoffs, or building structure as damaging stress.

8.2 Movement Accommodation Method

8.2.1 Thermal movement of straight runs shall be accommodated by expansion loops, offsets, or expansion joints sized for the calculated movement between anchors at the design temperature range.

8.2.2 Expansion loops and pipe offsets shall be the preferred method where routing and space permit, and packed or bellows expansion joints shall be used where space does not permit a loop.

Primary Thermal Movement Accommodationradio

● Expansion loops

○ Pipe offsets / direction changes

○ Packed expansion joints

○ Bellows expansion joints

NOTE Expansion loops have no packing or bellows to fail and require no maintenance, so they are preferred wherever the routing affords room; expansion joints are reserved for constrained locations and accept a maintenance obligation in exchange for compactness. (8.2.3)

8.3 Anchors and Guides

8.3.1 Pipe anchors shall be provided to divide piping into segments whose thermal movement is directed into the expansion device, and pipe guides shall be provided to keep movement axial.

8.3.2 Anchors shall be attached to building structure capable of resisting the calculated anchor loads, coordinated with the structural Engineer of Record where loads are significant.

8.3.3 Anchor and guide locations shall be coordinated with Hangers And SupportsHangers and Supports for Mechanical Piping and EquipmentResolves to the current edition.sync/hangers-and-supports so that support points do not restrain intended thermal movement.

9 Pipe Sleeves and Sleeve Seals

NOTE Piping that passes through walls, floors, and foundations requires sleeves so the pipe can pass freely, and at waterproof and rated conditions the annular space must be sealed against water or fire. (9.1)

9.2 Sleeve Sizing

9.2.1 Sleeves shall be sized a minimum of two pipe sizes larger than the pipe outside diameter, or sized to provide a 1-inch clearance around the insulation outside diameter, whichever is larger.

9.2.2 Sleeve sizing shall account for the insulation thickness and the modular seal clearance, not the bare-pipe outside diameter shown on structural drawings.

Sleeve Clearance Basisradio

● 1 in. clearance around insulation OD

○ Two pipe sizes larger than pipe OD

○ Sized to selected modular seal model

9.2.3 Sleeve sizing shall be reconciled against the insulated pipe outside diameter plus the required seal annular clearance before sleeves are set, not against the bare-pipe size shown on structural drawings.

NOTE Structural drawings commonly show bare-pipe sleeve sizes; once insulation thickness and seal clearance are added the sleeve is undersized if not reviewed before placement. (9.2.4)

9.3 Sleeve Seals

9.3.1 Penetrations through below-grade walls, foundation walls, and other waterproof conditions shall be sealed with modular mechanical sleeve seals consisting of interlocking elastomer links drawn tight by bolted pressure plates.

9.3.2 Penetrations through finished surfaces in occupied spaces shall be finished with escutcheons sized to the insulated pipe.

9.3.3 The modular seal model shall be selected for the actual sleeve inside diameter and pipe outside diameter, and the link count shall fill the annular space to the manufacturer's pressure rating.

Waterproof Penetration Seal Typeradio

● Modular mechanical sleeve seal (interlocking links)

○ Cast-in-place sleeve with hydrophilic waterstop

9.4 Rated Penetration Firestopping

9.4.1 Penetrations of fire-resistance-rated walls, floors, and ceilings shall be firestopped with a listed firestop system tested to ASTM E814 and providing an hourly rating equal to the rating of the assembly penetrated, and not less than 1 hour.

Floor-to-Floor Penetration Firestop Ratingradio

● 2

○ 1

○ 3

9.4.2 The firestop system installed at each rated penetration shall be a listed assembly appropriate to the penetrant, sleeve, and annular dimensions at that condition.

9.4.3 The listed firestop system shall be identified by penetration condition in the firestop submittal, including penetrant type, sleeve material and inside diameter, and annular dimension, so that the installed assembly matches the tested configuration.

NOTE Omitting firestopping from the common work section leaves firestop submittals uncoordinated across mechanical, electrical, and plumbing trades and invites incompatible product combinations at a shared penetration. (9.4.4)

10 Meters and Gages

NOTE Pressure gages, thermometers, flow indication, and test access ports allow the system to be read, balanced, and serviced; specifying them in the common work section ensures the access the balancing technicians and operators need is built in rather than added by change order. (10.1)

10.2 Pressure Gages

10.2.1 Liquid-filled pressure gages with stainless Bourdon tubes shall be installed at pump suction and discharge, at major equipment connections, and where required to read system pressure.

10.2.2 Gage scale range shall be approximately twice the maximum working pressure so that the normal operating pressure falls within the middle third of the scale.

Pressure Gage Rangeradio

● 0–100

○ 0–60

○ 0–160

○ 0–200

NOTE A gage whose normal reading sits at the very bottom or top of its scale cannot be read accurately; selecting the range at roughly twice working pressure keeps the operating point in the legible middle third. (10.2.3)

10.2.4 The pressure gage dial size shall be specified for each application, sized for legibility at the installation location.

Pressure Gage Dial Sizeradio

● 4-1/2

○ 6

○ 3-1/2

10.3 Thermometers

10.3.1 Adjustable-angle bimetal or digital thermometers shall be installed at equipment inlets and outlets and where required to read fluid temperature, with a scale range appropriate to the service.

Thermometer Typeradio

● Adjustable-angle bimetal, separable thermowell

○ Digital remote-reading, separable thermowell

Thermometer Rangeradio

● 35–250

○ 0–150

○ 30–300

10.3.2 Every thermometer in a piping system shall be installed in a separable thermowell so that it can be removed and replaced without draining the system.

10.3.3 Thermowells shall be provided at every thermometer location so that thermometers can be removed and replaced without draining the system.

NOTE A thermometer installed without a thermowell cannot be serviced unless the system is drained; specifying the thermowell as part of the common instrument installation prevents this maintenance constraint. (10.3.4)

10.4 Test Plugs

10.4.1 Self-sealing test plugs rated for the system pressure and temperature shall be installed at equipment inlets and outlets and at coil connections to provide temperature and pressure access for balancing without draining the system.

Test Plug Service Ratingrange

PSI

150500

Default: 200 PSI

10.4.2 Self-sealing test plugs shall be specified at all equipment inlet and outlet connections and at all coil connections.

NOTE Omitting test plugs from the common work section leaves the balancing technician without pressure and temperature access ports; adding them during balancing generates change orders. (10.4.3)

11 Equipment Supports and Seismic Restraint

NOTE Mechanical equipment must be supported and, in higher seismic design categories, restrained so that it does not shift, overturn, or break its connections under load. This section sets the thresholds; detailed restraint design and isolation belong to the supports and vibration sections. (11.1)

11.2 Equipment Supports

11.2.1 Floor-mounted equipment shall be set on housekeeping pads or structural curbs and anchored to resist the operating, startup, and service loads.

11.2.2 Suspended equipment shall be supported from building structure through hangers and supports coordinated with Hangers And SupportsHangers and Supports for Mechanical Piping and EquipmentResolves to the current edition.sync/hangers-and-supports.

11.3 Seismic Restraint Thresholds

11.3.1 The seismic design category of the project shall be declared in the basis of design, and seismic restraint of mechanical equipment shall be provided where required by ASCE 7 Chapter 13 for that category.

Seismic Design Categoryradio

○ A

○ B

○ C

○ D

○ E

○ F

Per drawings (deferred by default)

11.3.2 In Seismic Design Categories D, E, and F, mechanical components shall be braced and anchored per ASCE 7 Chapter 13.

11.3.3 In Seismic Design Category C, equipment shall be anchored per the importance factor and weight thresholds of ASCE 7.

Component Importance Factor (Ip)radio

● 1.0 (standard occupancy)

○ 1.5 (essential facility / life-safety component)

11.3.4 The contract documents shall assign responsibility for seismic restraint design, whether to the structural Engineer of Record, to delegated contractor design, or to pre-engineered listed restraint systems.

Seismic Restraint Design Responsibilityradio

● Delegated contractor design with pre-engineered listed systems

○ Structural Engineer of Record

11.3.5 The assignment of seismic restraint design responsibility shall be made explicit in the contract documents and shall not be left to be resolved through RFIs in the field.

NOTE Failing to assign seismic restraint design responsibility is a recurrent source of RFIs and schedule delays in Seismic Design Category C and above. (11.3.6)

NOTE Vibration isolation bases, inertia pads, and seismic snubbers themselves are governed by Vibration Isolation And Seismic RestraintVibration Isolation and Seismic RestraintResolves to the current edition.sync/vibration-isolation-and-seismic-restraint; this section sets only the threshold at which restraint is required. (11.3.7)

12 Cutting and Patching

NOTE Mechanical rough-in requires cutting and patching of building construction, which must be controlled so that structural and rated assemblies are not compromised. (12.1)

12.2 Cutting of Construction

12.2.1 Cutting and core drilling for mechanical work shall be performed so as not to impair the strength, weather resistance, or fire rating of any assembly, and structural members shall not be cut, notched, or bored without written approval of the structural Engineer of Record.

12.2.2 Penetrations cut through rated assemblies shall be firestopped to restore the assembly rating per the rated-penetration firestopping requirements of this section.

12.3 Patching

12.3.1 Surfaces disturbed by mechanical work shall be patched and finished to match the adjacent undisturbed construction in material, texture, and finish.

13 Field Startup and Acceptance Testing

NOTE Before systems are handed to the balancing contractor and the owner, the installing contractor must prove the piping holds pressure and the rotating equipment runs correctly. This field acceptance test is distinct from formal balancing. (13.1)

13.2 The field acceptance testing in this section is distinct from the testing, adjusting, and balancing governed by Testing Adjusting And BalancingTesting, Adjusting, and Balancing for HVACResolves to the current edition.sync/testing-adjusting-and-balancing; both are required and shall not be conflated.

13.3 Pressure Testing

13.3.1 Each piping system shall be pressure-tested before insulation is applied and before the system is concealed, at a test pressure of not less than 1.5 times the system design working pressure per ASME B31.9.

13.3.2 The test pressure shall be held for not less than 2 hours with no visible leakage and no pressure drop exceeding 5 PSI.

13.3.3 Pressure tests shall be hydrostatic unless a pneumatic test is specifically authorized in writing for a system that cannot tolerate the test fluid, in which case the additional pneumatic-test safety precautions of ASME B31.9 shall apply.

Pressure Test Methodradio

● Hydrostatic

○ Pneumatic (only where authorized for systems intolerant of test fluid)

Hydrostatic Test Pressurerange

PSI

100375

Default: 150 PSI

Minimum Test Hold Timerange

hr

28

Default: 2 hr

13.4 Motor Rotation and Operational Check

13.4.1 Before any motor-driven equipment is operated under load, the Contractor shall verify the rotation direction against the equipment manufacturer's rotation arrow with a momentary first-start check.

13.4.2 Each system shall be operated through a startup check confirming that pumps, fans, and equipment run without abnormal noise, vibration, or overheating, and that flow and pressure readings are within the expected range before the system is released to balancing.

NOTE Verifying rotation before operating under load prevents pumps and fans from running backward, which on some equipment produces apparently normal but reduced output that is not detected until balancing fails to make setpoints. (13.4.3)

14 Warranty

NOTE A defined warranty period sets the owner's recourse for defective mechanical workmanship and materials after substantial completion. (14.1)

14.2 Workmanship Warranty

14.2.1 The Contractor shall warrant all mechanical work against defects in materials and workmanship for the warranty period declared below, measured from the date of substantial completion.

14.2.2 During the warranty period the Contractor shall repair or replace defective work and any other work damaged by the defect or its correction at no cost to the owner.

14.2.3 Manufacturer warranties on equipment and components shall be assigned to the owner and shall run for their full term where that term exceeds the workmanship warranty period.

Workmanship Warranty Periodradio

● 1 year from substantial completion

○ 2 years from substantial completion

15 Spare Parts

NOTE Furnishing a defined set of spare parts at closeout lets the owner service the common mechanical components without sourcing delay. (15.1)

15.2 Furnished Spares

15.2.1 The Contractor shall furnish spare valve trim, gage and thermometer elements, and seal kits as required by the individual equipment sections, delivered to the owner at substantial completion.

15.2.2 Spare parts shall be the products of the same manufacturers as the installed components so that they are interchangeable with the installed work.