1 Scope
1.1This standard governs the materials, ratings, end connections, operators, identification, and acceptance testing of general-duty valves installed in domestic water piping within building interiors.
NOTE General-duty valves are the isolation, check, and flow-balancing valves that serve the building water distribution system rather than a single packaged appliance. (1.1.1)
NOTE This standard covers gate, ball, globe, and butterfly isolation valves; swing, silent (spring-loaded), and wafer check valves; and manual and automatic balancing valves, in domestic potable cold water, domestic hot water, and hot water recirculation service. (1.1.2)
NOTE Coverage extends from the building water service entrance through all interior distribution piping to fixture shutoffs and equipment connections. (1.1.3)
1.1.4Valves shall be furnished and installed for the size range NPS 1/4 through NPS 12 (DN 8 through DN 300) inclusive.
1.1.5Valves shall be suitable for continuous service at system pressures up to 250 psi cold working pressure (CWP) and water temperatures up to 250 degF.
1.1.6Each valve in contact with potable water shall carry current third-party certification to NSF/ANSI 61 and NSF/ANSI/CAN 372.
NOTE This standard is a plumbing-discipline companion to
Hvac Piping Valves; the two share valve types and manufacturers but differ in that potable-water lead-free certification is mandatory here, and valve placement is governed by the plumbing code rather than the mechanical code.
(1.1.7) NOTE The following are outside this standard and are governed elsewhere: (1.1.8)
- Hydronic heating, chilled water, and condenser water valves are covered by Hvac Piping Valves.
- Backflow prevention assemblies (RPZ, double check, pressure vacuum breaker) are covered by Backflow Prevention.
- Thermostatic mixing valves, pressure-reducing valves, and water hammer arrestors are covered by Plumbing Specialties.
- Fire protection sprinkler and standpipe control valves are a separate discipline and are not within plumbing valve scope.
- Buried waterworks utility gate valves NPS 4 and larger are AWWA C509/C515 territory, despite the overlapping NPS range, and are not within building interior scope.
- Natural gas shutoff and service valves are covered by Natural Gas Piping.
- Pipe, fittings, insulation, and distribution routing are covered by Domestic Water Piping.
- Hangers, supports, and seismic restraints for valve bodies are covered by Hangers And Supports.
2 Referenced Standards
2.1Equipment, materials, and installation shall comply with the latest adopted edition of each of the following unless a specific edition is cited.
2.2Where referenced standards conflict, the more stringent requirement shall govern unless the Engineer of Record directs otherwise in writing.
| Standard |
Title |
| MSS SP-67 |
Butterfly Valves |
| MSS SP-71 |
Gray Iron Swing Check Valves |
| MSS SP-80 |
Bronze Gate, Globe, Angle and Check Valves |
| MSS SP-110 |
Ball Valves Threaded, Socket-Welding, Solder Joint, Grooved and Flared Ends |
| MSS SP-125 |
Gray Iron and Ductile Iron In-Line Spring Loaded Center-Guided Check Valves |
| ASME B16.34 |
Valves - Flanged, Threaded, and Welding End |
| ASME B16.10 |
Face-to-Face and End-to-End Dimensions of Valves |
| ASME B31.9 |
Building Services Piping |
| NSF/ANSI 61 |
Drinking Water System Components - Health Effects |
| NSF/ANSI/CAN 372 |
Drinking Water System Components - Lead Content |
| IPC |
International Plumbing Code (Section 606, Water Supply and Distribution) |
| UPC |
Uniform Plumbing Code (Chapter 6, Water Supply and Distribution) |
| AWWA C800 |
Underground Service Line Valves and Fittings |
3 Submittals
3.1 Action Submittals
3.1.1The Contractor shall submit the following action submittals for review before procurement:
- Product data for each valve type, size, and pressure class, including the manufacturer's catalog cut showing body material, trim, seat, stem, and operator.
- Documentation of NSF/ANSI 61 and NSF/ANSI/CAN 372 listing for each valve in potable water service, identifying the certifying agency and listing number.
- Pressure-temperature rating curves or tables for each valve, demonstrating that the rating exceeds the system design pressure plus the water hammer allowance.
- A valve schedule correlating each valve number to its type, size, service, location, and normal operating position.
- Shop drawings for valves requiring chain operators, gear operators, extended stems, or access provisions, showing dimensions and clearances.
☑ Valve product data (body, trim, seat, stem, operator)
☑ NSF 61 / NSF 372 certification listing
☑ Pressure-temperature rating data
☑ Valve schedule (number, type, size, service, position)
☐ Shop drawings for geared, chain, or extended-stem valves
3.2.1The Contractor shall submit the following informational submittals:
- Certified factory hydrostatic shell and seat test reports for valves NPS 2-1/2 and larger.
- Field hydrostatic pressure test records for the completed valve installation.
- Manufacturer's installation, operation, and maintenance instructions.
☐ Factory shell and seat test reports (NPS 2-1/2 and larger)
☑ Field hydrostatic pressure test records
☑ Installation, operation, and maintenance instructions
3.3 Closeout Submittals
3.3.1The Contractor shall submit the following closeout submittals before final acceptance:
- A final as-built valve schedule reflecting installed valve numbers, types, and locations.
- Operation and maintenance manuals compiling product data, spare-parts lists, and maintenance procedures for each valve type.
☑ As-built valve schedule
☑ Operation and maintenance manuals
☐ Spare-parts list
4 Quality Assurance
4.1Each valve type shall be the product of a single manufacturer regularly engaged in the production of that valve type.
NOTE Standardizing each valve type on one manufacturer simplifies spare-parts stocking, operator familiarity, and warranty administration over the life of the building. (4.1.1)
4.2Valves of the same type and size shall be identical and interchangeable throughout the project.
4.3Each valve shall be permanently marked by the manufacturer with the body material, pressure rating, size, and applicable standard designation, in accordance with ASME B16.34 and the governing MSS standard.
NOTE Permanent body markings let a field inspector or future maintainer confirm a valve's rating without the original submittal, which is essential once the valve schedule is lost or the building changes hands. (4.3.1)
4.4Bronze and brass valves NPS 2 and under shall comply with MSS SP-80 (gate, globe, check) or MSS SP-110 (ball) as applicable to the valve type.
4.5Iron body swing check valves shall comply with MSS SP-71, and iron body butterfly valves shall comply with MSS SP-67.
4.6Silent (spring-loaded center-guided) check valves shall comply with MSS SP-125.
4.7Every valve wetted component in potable water service shall be certified to NSF/ANSI 61 for health effects and to NSF/ANSI/CAN 372 for lead content.
NOTE NSF 61 and NSF 372 are separate certifications: NSF 61 is a leach test for health effects, and NSF 372 is a wetted-surface lead-content analysis limiting lead to 0.25 percent. A valve listed to one is not automatically listed to the other. (4.7.1)
NOTE Specify lead-free compliance by certification listing, not by a material claim alone. Manufacturer literature sometimes asserts compliance without a formal third-party listing, which the certification listing requirement closes. (4.7.2)
NOTE The Safe Drinking Water Act (Section 1417) has required lead-free wetted components for potable water service on components installed on or after January 4, 2014. (4.7.3)
5 Environmental and Service Conditions
5.1Valves shall be selected for the service pressure, temperature, and water chemistry of the system in which they are installed.
5.1.1The pressure-temperature rating of each valve shall exceed the system design working pressure plus a water hammer allowance of not less than 50 psi.
NOTE A 200 psi CWP valve covers a 150 psi system static pressure with a 50 psi water hammer margin, which is the safe default for most commercial plumbing distribution. Specifying a 150 psi CWP valve on such a system leaves no surge margin and is a common cause of premature seat and stem failure. (5.1.2)
5.2Valves in domestic hot water and hot water recirculation service shall be rated for continuous service at the maximum system water temperature.
NOTE Domestic hot water is typically distributed at or below 140 degF, well within the 250 degF service rating of the valves specified here; the rating margin accommodates recirculation, mixing-valve bypass, and thermal disinfection cycles. (5.2.1)
5.3Valves installed in water known to be soft, low-pH, or high in chloride shall be specified with dezincification-resistant (DZR) brass or bronze bodies.
NOTE Dezincification-susceptible yellow brass in aggressive water pits and fails the valve body within five to ten years; in jurisdictions with corrosive water, DZR brass or bronze is mandatory rather than optional. (5.3.1)
○ 150 psi CWP
● 200 psi CWP
○ 300 psi CWP
○ 600 psi CWP
○ Yes - aggressive water (soft, low-pH, or high-chloride)
● No - standard water chemistry
6 Valve Materials and Body Construction
6.1Valve body material shall be matched to valve size and service.
6.1.1Valves NPS 1/4 through NPS 2 shall have bronze or brass bodies.
6.1.2Valves NPS 2-1/2 and larger shall have cast iron or ductile iron bodies with bronze or stainless steel trim.
NOTE Bronze is the correct 80 percent-case body material at and below NPS 2; above NPS 2 bronze becomes non-standard and substantially more expensive, and iron body is the correct choice. Specifying bronze valves above NPS 2 is a common and avoidable cost overrun. (6.1.3)
6.1.4Stainless steel bodies shall be furnished where the water chemistry is aggressive beyond the corrosion resistance of DZR bronze, where indicated.
6.2Stems shall be bronze, brass, or stainless steel, and shall be free of dezincification-susceptible alloy in aggressive water service.
6.3Seats, discs, and resilient seals shall be selected by valve type.
6.3.1Ball valve seats shall be PTFE or reinforced TFE.
6.3.2Butterfly valve seats shall be EPDM or BUNA-N, suitable for potable water and for the service temperature.
6.3.3Gate, globe, and check valve seats shall be bronze or stainless steel as integral or renewable seat rings.
NPS 1/4-2: bronze/brass body
NPS 2-1/2-12: cast or ductile iron body, bronze trim
Stainless steel body (aggressive water)
● PTFE
○ Reinforced TFE (RTFE)
7 End Connections
7.1Valve end connections shall match the joining method of the adjacent piping.
7.1.1Threaded ends shall be tapered pipe thread (NPT) conforming to ASME B1.20.1.
7.1.2Solder-joint ends shall be furnished for connection to copper tube by soldered or brazed joint.
7.1.3Press-connect ends shall be furnished where the adjacent copper or stainless tube is joined by press fitting, and the press jaw profile shall match the adjacent piping system.
NOTE Press-connect valves require the same jaw profile as the adjacent press-fit piping; a mismatched jaw leaves a joint incompletely pressed and is a hidden leak path. Confirm jaw compatibility before specifying press-connect valves. (7.1.4)
7.1.5Grooved ends shall conform to the groove dimensions of the adjacent grooved coupling system.
7.1.6Flanged ends shall conform to ASME B16.1 (iron) Class 125 or Class 250 as required by the valve pressure rating, with face-to-face dimensions per ASME B16.10.
7.1.7Wafer and lug butterfly valves shall be installed between two mating flanges, and shall not be installed at a pipe end, union, or single-flange equipment nozzle.
NOTE A wafer valve is clamped between two flanges and has no body bolt holes of its own; specifying a wafer valve where only one mating flange exists creates an unfillable gap. A lug-style valve can terminate a run because it is tapped for through-bolts on each side. (7.1.8)
Threaded (NPT)
Solder joint
Press-connect
Grooved
Flanged (Class 125)
Flanged (Class 250)
Wafer (between flanges)
Lug (between or end of flange)
8 Isolation Valves
8.1Isolation valves provide full open / full closed shutoff of a piping segment and shall be selected by function and size.
8.1.1A valve selected for isolation shall be used only for full open / full closed service, not for throttling.
8.1.2Where flow regulation is required, a globe valve, balancing valve, or automatic balancing valve shall be used instead of an isolation valve.
NOTE Throttling a valve designed only for isolation erodes the seat and disc, which is why isolation service and throttling service must be separated at valve selection. (8.1.3)
8.2 Ball Valves
8.2.1Ball valves shall be the default isolation valve for piping NPS 2 and under in domestic water service.
8.2.2Ball valves shall be bronze body, full port, with a PTFE or RTFE seat and a blowout-proof stem, conforming to MSS SP-110.
8.2.3Ball valves shall be furnished with a lever handle, or with a tee handle where a lever would obstruct adjacent equipment.
NOTE Ball valves are the correct choice wherever a valve is operated frequently. They give bubble-tight shutoff and a clear quarter-turn open/closed indication, and they tolerate repeated cycling far better than gate valves. (8.2.4)
● Full port
○ Standard port
● Lever handle
○ Tee handle
○ Lever with locking provision
8.3 Gate Valves
8.3.1Gate valves NPS 2 and under shall be bronze or brass body, solid wedge, with a non-rising stem, conforming to MSS SP-80.
8.3.2Gate valves NPS 2-1/2 and larger shall be iron body, resilient or bronze-mounted wedge, flanged, with an outside screw and yoke (OS&Y) rising stem.
8.3.3Gate valves shall be used only where the valve is operated infrequently and remains in a fixed position.
NOTE Gate valves are designed for infrequent full-open / full-closed service. Where weekly or more frequent operation is expected, the stem packing and wedge wear prematurely; specify a ball valve for frequently operated isolation. (8.3.4)
NOTE OS&Y rising stems on large valves give a visible open/closed indication, which non-rising stems on small valves do not. (8.3.5)
● Non-rising stem (NRS)
○ Outside screw and yoke (OS&Y), rising stem
● Resilient seat
○ Bronze-mounted (metal seat)
8.4 Butterfly Valves
8.4.1Butterfly valves shall be furnished for isolation in piping NPS 2-1/2 and larger where a compact valve is required, conforming to MSS SP-67.
8.4.2Butterfly valves shall be iron body, wafer or lug type, with a stainless steel disc, a stainless steel or coated stem, and an EPDM or BUNA-N seat.
8.4.3Butterfly valves NPS 6 and larger, and any butterfly valve subject to frequent operation, shall be furnished with a gear operator and position indicator.
8.4.4Butterfly valves NPS 4 and smaller may be furnished with a lever (notched throttling plate) operator.
8.4.5Butterfly valves shall not be specified for throttling (partial-open) service; where flow regulation is required, a globe valve or an automatic balancing valve shall be used.
NOTE Partial-open operation erodes the butterfly seat and disc rapidly, which is why throttling service requires a valve type whose geometry is suited to it. (8.4.6)
○ Lever handle (NPS 4 and smaller)
● Gear operator with position indicator
8.5 Globe Valves
8.5.1Globe valves shall be furnished where throttling or frequent flow regulation is required in piping NPS 2 and under, conforming to MSS SP-80.
8.5.2Globe valves shall be bronze body with a renewable composition or PTFE disc suited to the service temperature.
NOTE The globe valve's seat geometry is designed for throttling and tolerates the erosive condition that destroys an isolation valve held partly open. (8.5.3)
9 Check Valves
9.1Check valves prevent reverse flow and shall be selected by orientation, velocity, and slam potential.
9.2 Swing Check Valves
9.2.1Swing check valves NPS 2 and under shall be bronze body, Class 125, with threaded or solder ends, conforming to MSS SP-80.
9.2.2Swing check valves NPS 2-1/2 and larger shall be iron body, Class 125, flanged, with bronze trim, conforming to MSS SP-71.
9.2.3Swing check valves shall be installed only in horizontal runs (or vertical runs with upward flow) where forward velocity is sufficient to hold the disc open.
9.2.4On vertical risers and pump discharge, a silent check valve shall be used in place of a swing check valve.
NOTE Swing check valves require a horizontal run and sufficient forward velocity to open and seat properly; on vertical risers or pump discharge they chatter and slam, making a spring-loaded silent check the correct selection. (9.2.5)
9.3 Silent (Spring-Loaded) Check Valves
9.3.1Silent check valves shall be furnished on pump discharge, on hot water recirculation pump discharge, and on vertical risers, conforming to MSS SP-125.
9.3.2Silent check valves shall be bronze or iron body, center-guided, spring-loaded, with a stainless steel spring, in wafer or flanged style.
NOTE The spring closes a silent check valve before flow reverses, eliminating the slam and water hammer that a swing check produces when pump flow stops. This non-slam behavior is why recirculation and pump-discharge service calls for silent checks. (9.3.3)
9.3.4Silent check valves in potable water service shall be NSF/ANSI 61 and NSF/ANSI/CAN 372 certified.
9.4 Wafer Check Valves
9.4.1Wafer check valves shall be furnished where installation space is constrained and the valve is installed between two flanges.
9.4.2Wafer check valves shall be dual-plate or center-guided spring type, with a stainless steel spring and EPDM or potable-rated seat.
Swing check - horizontal run, low velocity
Silent (spring-loaded) - pump discharge, recirculation, vertical riser
Wafer check - space-constrained between flanges
● Bronze (NPS 2 and under)
○ Iron body, bronze trim (NPS 2-1/2 and larger)
10 Balancing Valves
10.1Balancing valves shall be furnished on each hot water recirculation branch to distribute return flow and maintain delivery temperature throughout the loop.
10.1.1Each hot water recirculation branch shall have a balancing valve at its connection to the return main.
NOTE A recirculation loop without balancing valves at each branch starves the far branches and over-circulates the near ones, producing cold delivery at distant fixtures and scalding risk near the heater. Balancing valves equalize the return flow so every fixture receives hot water promptly. (10.1.2)
10.2 Manual Balancing Valves
10.2.1Manual balancing valves shall be the memory-stop type with integral measuring ports for differential pressure readout.
10.2.2Manual balancing valves shall be furnished for recirculation branches NPS 3/4 and NPS 1 as the default selection.
NOTE A memory stop lets the balancer set, lock, and later re-establish the calibrated position after the valve has been closed for service, preserving the commissioned balance. (10.2.3)
10.3 Automatic Balancing Valves
10.3.1Automatic (pressure-independent) balancing valves shall be furnished where the recirculation system experiences variable differential pressure that a fixed-orifice manual valve cannot accommodate.
10.3.2Automatic balancing valves shall be cartridge-type, bronze body, maintaining the set flow within plus or minus 10 percent over a differential pressure range of 2 psi to 50 psi.
NOTE A pressure-independent valve holds its set flow automatically as system differential pressure swings, which a manual memory-stop valve cannot do; it is the right choice where pumps cycle or loads vary widely. (10.3.3)
● Manual memory-stop (fixed orifice, measuring ports)
○ Automatic pressure-independent (cartridge)
NPS 1/2
NPS 3/4
NPS 1
NPS 1-1/4
NPS 1-1/2
11 Operators and Stem Provisions
11.1Valve operators shall be selected for valve size, operating frequency, and accessibility.
11.1.1Valves up to NPS 6 shall be hand-operated by lever, handwheel, or gear as appropriate to the valve type.
11.1.2Valves NPS 8 and larger, and any valve more than 7 ft above the finished floor, shall be furnished with a gear operator and, where above reach, a chain wheel.
11.1.3Chain-operated valves shall have the chain looped to terminate approximately 6 ft above the finished floor.
11.2Valves in insulated piping shall be furnished with stem extensions clearing the insulation.
11.2.1Stem extensions shall project not less than 2 in. (50 mm) beyond the outside diameter of the pipe insulation.
11.2.2Valves in cold or chilled water piping with vapor-barrier insulation shall be furnished with extended stems and non-conducting handles so the insulator does not breach the vapor barrier at each valve.
NOTE Omitting extended stems on vapor-barrier-insulated piping forces the insulator to cut the vapor barrier at every valve, creating condensation entry points that wet the insulation and corrode the pipe. The extension lets the insulation and vapor barrier run continuous past the valve. (11.2.3)
Lever handle
Handwheel
Gear operator
Gear operator with chain wheel
● Not required (uninsulated)
○ Standard extension (>= 2 in. beyond insulation OD)
○ Extended stem with non-conducting handle (vapor-barrier insulation)
12 Identification
12.1Each valve other than a fixture supply stop shall be permanently identified and keyed to the project valve schedule.
12.1.1Each valve shall carry a brass or stainless steel tag stamped with its valve number.
12.1.2Valve tag characters shall be not less than 1/2 in. (13 mm) high.
12.1.3Valve tags shall be attached with stainless steel wire, chain, or a non-corroding fastener.
12.1.4A framed, laminated valve schedule correlating each valve number to its type, size, service, and location shall be mounted in the mechanical room.
12.1.5Valves concealed above inaccessible ceilings or behind walls shall be located by an access panel or shown on the as-built drawings by concealed valve locations. NOTE Valves installed without tags and a valve schedule become unlocatable once the walls close, generating RFIs during commissioning and obstructing maintenance for the life of the building. The numbering system keyed to the schedule is what makes a valve findable years later. (12.1.6)
● Brass
○ Stainless steel
○ Anodized aluminum
13 Testing
13.1Valves shall be factory-tested and the installed system shall be field-pressure-tested before acceptance.
13.1.1Each valve shall pass a factory shell hydrostatic test at 1.5 times the cold working pressure, per ASME B16.34.
13.1.2Each valve shall pass a factory seat closure test at 1.1 times the rated pressure, per the governing MSS standard for its type.
13.1.3The completed valve installation shall be field hydrostatically tested at 1.5 times the system design working pressure for a minimum of 4 hours, per ASME B31.9 Section 937.4.
13.1.4The field pressure test shall show no visible leakage at any joint or valve stem.
13.1.5Valves shall be in the full-open position during system pressure testing, except where a valve must isolate a section being tested separately.
NOTE Leaving valves open during the test proves the full system piping, not just the valve seats; closing a valve during a system test hides any leak path beyond it. (13.1.6)
14 Installation
14.1Valves shall be installed accessible for operation, maintenance, and removal.
14.1.1Each valve shall be installed with its operator and any measuring ports accessible without removing adjacent equipment or finished construction.
14.1.2Valves shall be installed in the orientation recommended by the manufacturer; check valves shall be installed with the flow arrow oriented in the direction of normal flow.
14.1.3Isolation valves shall be installed where required by the plumbing code, including at each fixture supply, each equipment connection, each branch serving two or more fixtures, each riser, and at the building water service entrance, per IPC Section 606 or the equivalent UPC provision.
NOTE The plumbing code's valve placement rules exist so that any fixture, branch, riser, or piece of equipment can be isolated for service without draining the whole system. Honoring them at design time avoids field-added valves and service shutdowns later. (14.1.4)
14.1.5Unions or flanges shall be installed adjacent to threaded and flanged valves NPS 2 and under to permit valve removal without cutting the pipe.
14.1.6Valves shall not be supported by the connected piping; valve weight shall be carried by the pipe supports in Hangers And Supports. 14.1.7Valves shall be installed with stems oriented between the vertical-up and horizontal positions, and shall not be installed stem-down where sediment can collect on the stem and seat.
14.1.8Dielectric isolation shall be maintained where a valve joins dissimilar metals, consistent with the piping requirements of Domestic Water Piping. 14.1.9Before installation, each valve shall be inspected and its interior cleared of shipping debris, and threaded ends shall be made up with a pipe-thread sealant compatible with potable water.
● Union adjacent to valve
○ Flange adjacent to valve
○ Press or grooved coupling permits removal
15 Delivery, Storage, and Handling
15.1Valves shall be protected from damage and contamination from delivery through installation.
15.1.1Valves shall be delivered with end protectors in place and with factory tags and markings intact.
15.1.2Valves shall be stored indoors, off the ground, and protected from dirt, moisture, and freezing until installed.
15.1.3Valves shall be handled by the body, not by the operator, handle, or stem, to avoid distorting the stem or seat.
15.1.4Valves shall be kept in the closed or partly open position during storage as recommended by the manufacturer to protect the seat.
16 Warranty
16.1The Contractor shall warrant valves against defects in materials and workmanship for the warranty period.
16.1.1Valves shall be warranted for a period of not less than one year from the date of substantial completion.
16.1.2Specific valve types may carry an extended manufacturer warranty where indicated.
● 1 year from substantial completion
○ 2 years from substantial completion
○ Manufacturer standard warranty
17 Spare Parts
17.1The Contractor shall furnish spare parts and operating provisions to the Owner at closeout.
17.1.1The Contractor shall furnish spare seats, discs, and stem packing kits for valves NPS 2-1/2 and larger, in the quantity indicated.
17.1.2The Contractor shall furnish a wrench or operating key for each type of valve requiring a removable operator.
☐ Spare seats and discs (NPS 2-1/2 and larger)
☐ Stem packing kits
☑ Operating wrenches / keys for removable operators