Corpus sync: neutrality remakes, note hygiene, datasheet relocation, transformer-split cross-refs
---
title: General-Duty Valves for Plumbing Piping
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swing check, silent check, wafer check, and manual or automatic balancing valves
NPS 1/4 through NPS 12 from the water service entrance to fixture shutoffs and
− equipment connections, rated to 250 psi CWP and 250 degF, with mandatory NSF 61/372
+ equipment connections, rated to 250 psi CWP and 250°F, with mandatory NSF 61/372
lead-free certification.
Not intended for: hydronic heating, chilled, and condenser water valves (see
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### Valves shall be furnished and installed for the size range NPS 1/4 through NPS 12 (DN 8 through DN 300) inclusive.
−### Valves shall be suitable for continuous service at system pressures up to 250 psi cold working pressure (CWP) and water temperatures up to 250 degF.
+### Valves shall be suitable for continuous service at system pressures up to 250 psi cold working pressure (CWP) and water temperatures up to 250°F.
### Each valve in contact with potable water shall carry current third-party certification to NSF/ANSI 61 and NSF/ANSI/CAN 372.
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### The pressure-temperature rating of each valve shall exceed the system design working pressure plus a water hammer allowance of not less than 50 psi.
−### 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. {note}
−
−## Valves in domestic hot water and hot water recirculation service shall be rated for continuous service at the maximum system water temperature.
−
−### 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. {note}
−
−## Valves installed in water known to be soft, low-pH, or high in chloride shall be specified with dezincification-resistant (DZR) brass or bronze bodies.
−
−### 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. {note}
−
```datasheet
label: System design working pressure
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```
+### 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. {note}
+
+## Valves in domestic hot water and hot water recirculation service shall be rated for continuous service at the maximum system water temperature.
+
```datasheet
label: Maximum service water temperature
type: range
−unit: degF
+unit: °F
min: 40
max: 250
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```
+### Domestic hot water is typically distributed at or below 140°F, well within the 250°F service rating of the valves specified here; the rating margin accommodates recirculation, mixing-valve bypass, and thermal disinfection cycles. {note}
+
+## Valves installed in water known to be soft, low-pH, or high in chloride shall be specified with dezincification-resistant (DZR) brass or bronze bodies.
+
```datasheet
label: Dezincification-resistant (DZR) brass/bronze required
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```
+### 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. {note}
+
# Valve Materials and Body Construction {toc}
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## Valve end connections shall match the joining method of the adjacent piping.
+```datasheet
+label: End connection type
+type: select
+options:
+ - Threaded (NPT)
+ - Solder joint
+ - Press-connect
+ - Grooved
+ - Flanged (Class 125)
+ - Flanged (Class 250)
+ - Wafer (between flanges)
+ - Lug (between or end of flange)
+default: Threaded (NPT)
+```
+
### Threaded ends shall be tapered pipe thread (NPT) conforming to ASME B1.20.1.
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### 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. {note}
−```datasheet
−label: End connection type
−type: select
−options:
− - Threaded (NPT)
− - Solder joint
− - Press-connect
− - Grooved
− - Flanged (Class 125)
− - Flanged (Class 250)
− - Wafer (between flanges)
− - Lug (between or end of flange)
−default: Threaded (NPT)
−```
−
# Isolation Valves {toc}
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### Where flow regulation is required, a globe valve, balancing valve, or automatic balancing valve shall be used instead of an isolation valve.
−### 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. {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.
## Ball Valves {toc}
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### Ball valves shall be bronze body, full port, with a PTFE or RTFE seat and a blowout-proof stem, conforming to MSS SP-110.
−### Ball valves shall be furnished with a lever handle, or with a tee handle where a lever would obstruct adjacent equipment.
−
−### 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. {note}
−
```datasheet
label: Ball valve port
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```
+### Ball valves shall be furnished with a lever handle, or with a tee handle where a lever would obstruct adjacent equipment.
+
```datasheet
label: Ball valve handle type
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```
+### 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. {note}
+
## Gate Valves {toc}
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### Gate 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.
+```datasheet
+label: Gate valve seat (NPS 2-1/2 and larger)
+type: radio
+options:
+ - Resilient seat
+ - Bronze-mounted (metal seat)
+default: Resilient seat
+```
+
### Gate valves shall be used only where the valve is operated infrequently and remains in a fixed position.
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### OS&Y rising stems on large valves give a visible open/closed indication, which non-rising stems on small valves do not. {note}
+### The gate valve stem type shall be specified as non-rising stem or outside screw and yoke, based on the valve size and the position indication required.
+
```datasheet
label: Gate valve stem type
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```
−```datasheet
−label: Gate valve seat (NPS 2-1/2 and larger)
−type: radio
−options:
− - Resilient seat
− - Bronze-mounted (metal seat)
−default: Resilient seat
−```
−
## Butterfly Valves {toc}
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### Butterfly 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.
−### Butterfly valves NPS 6 and larger, and any butterfly valve subject to frequent operation, shall be furnished with a gear operator and position indicator.
−
−### Butterfly valves NPS 4 and smaller may be furnished with a lever (notched throttling plate) operator.
−
−### Butterfly 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.
−
−### 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. {note}
−
```datasheet
label: Butterfly valve end style
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```
+### Butterfly valves NPS 6 and larger, and any butterfly valve subject to frequent operation, shall be furnished with a gear operator and position indicator.
+
+### Butterfly valves NPS 4 and smaller may be furnished with a lever (notched throttling plate) operator.
+
+### Butterfly 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.
+
+### 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. {note}
+
+### The butterfly valve operator shall be specified as a lever handle or a gear operator with position indicator, based on valve size and frequency of operation.
+
```datasheet
label: Butterfly valve operator
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### Automatic (pressure-independent) balancing valves shall be furnished where the recirculation system experiences variable differential pressure that a fixed-orifice manual valve cannot accommodate.
−### Automatic 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.
−
−### 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. {note}
−
```datasheet
label: Balancing valve type
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```
+### Automatic 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.
+
+### 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. {note}
+
+### The manual balancing valve size shall be specified for each recirculation branch, sized to the branch it serves.
+
```datasheet
label: Manual balancing valve size (recirculation branch)
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## Valve operators shall be selected for valve size, operating frequency, and accessibility.
−### Valves up to NPS 6 shall be hand-operated by lever, handwheel, or gear as appropriate to the valve type.
−
−### Valves 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.
−
−### Chain-operated valves shall have the chain looped to terminate approximately 6 ft above the finished floor.
−
−## Valves in insulated piping shall be furnished with stem extensions clearing the insulation.
−
−### Stem extensions shall project not less than 2 in. (50 mm) beyond the outside diameter of the pipe insulation.
−
−### Valves 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.
−
−### 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. {note}
−
```datasheet
label: Operator type
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```
+### Valves up to NPS 6 shall be hand-operated by lever, handwheel, or gear as appropriate to the valve type.
+
+### Valves 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.
+
+### Chain-operated valves shall have the chain looped to terminate approximately 6 ft above the finished floor.
+
+## Valves in insulated piping shall be furnished with stem extensions clearing the insulation.
+
```datasheet
label: Stem extension for insulated piping
type: radio
options:
- "Not required (uninsulated)"
− - "Standard extension (>= 2 in. beyond insulation OD)"
+ - "Standard extension (≥ 2 in. beyond insulation OD)"
- "Extended stem with non-conducting handle (vapor-barrier insulation)"
default: "Not required (uninsulated)"
```
+### Stem extensions shall project not less than 2 in. (50 mm) beyond the outside diameter of the pipe insulation.
+
+### Valves 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.
+
+### 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. {note}
+
# Identification {toc}
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### Each valve shall carry a brass or stainless steel tag stamped with its valve number.
−### Valve tag characters shall be not less than 1/2 in. (13 mm) high.
−
−### Valve tags shall be attached with stainless steel wire, chain, or a non-corroding fastener.
−
−### A framed, laminated valve schedule correlating each valve number to its type, size, service, and location shall be mounted in the mechanical room.
−
−### Valves concealed above inaccessible ceilings or behind walls shall be located by an access panel or shown on the as-built drawings by [[drawing: concealed valve locations]].
−
−### 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. {note}
−
```datasheet
label: Valve tag material
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```
+### Valve tag characters shall be not less than 1/2 in. (13 mm) high.
+
+### Valve tags shall be attached with stainless steel wire, chain, or a non-corroding fastener.
+
+### A framed, laminated valve schedule correlating each valve number to its type, size, service, and location shall be mounted in the mechanical room.
+
+### Valves concealed above inaccessible ceilings or behind walls shall be located by an access panel or shown on the as-built drawings by [[drawing: concealed valve locations]].
+
+### 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. {note}
+
# Testing {toc}
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### The 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.
−### The field pressure test shall show no visible leakage at any joint or valve stem.
−
−### Valves shall be in the full-open position during system pressure testing, except where a valve must isolate a section being tested separately.
−
−### 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. {note}
−
```datasheet
label: Field test pressure
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```
+### The field pressure test shall show no visible leakage at any joint or valve stem.
+
+### Valves shall be in the full-open position during system pressure testing, except where a valve must isolate a section being tested separately.
+
+### 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. {note}
+
# Installation {toc}
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- Operating wrenches / keys for removable operators
```