1 Scope
NOTE This standard covers the selection, materials, performance requirements, finishes, freeze and scald protection, access, installation, and acceptance testing of plumbing specialties — the drainage and water-distribution devices that serve the plumbing system without being fixtures, piping, or backflow assemblies in their own right. (1.1)
NOTE The specialties covered are cleanouts; floor and area drains; trap seal protection devices (trap primers and barrier-type trap seal protection devices); hose bibbs and freezeless wall hydrants; water hammer arrestors; backwater valves; and thermostatic mixing valves, both master-distribution and point-of-use. (1.2)
NOTE These items are small relative to the piping and fixtures around them, but each one prevents a specific, well-understood failure mode, and omitting or mis-rating any of them produces problems that are expensive to find and correct after the building is occupied. (1.3)
NOTE A missing trap primer admits sewer gas to occupied space; an undersized or omitted water hammer arrestor produces banging pipes and eventual joint failure; a wall hydrant without freeze protection bursts in the wall; a backwater valve omitted on a below-grade fixture floods a basement during a sewer surcharge; and a mixing valve set wrong scalds an occupant. (1.4)
NOTE The scope of each specialty begins at its connection to the serving pipe and includes the body, the operating or sealing element, the trim and access cover, and the freeze, scald, or backflow protection integral to the device. (1.5)
NOTE The serving water and drainage piping, the fixtures, and the building backflow assemblies are covered by their own standards and are referenced — not duplicated — here. (1.6)
NOTE Coordinate specialty locations, body sizes, grate and cover types, and duty ratings with
the plumbing floor plans and the plumbing fixture and specialty schedule, and coordinate drainage connections with
Sanitary Waste And Vent Piping and water connections with
Domestic Water Piping.
(1.7) 2 Referenced Standards
2.1Materials, devices, and installation shall comply with the latest adopted edition of the following standards and codes unless a specific year is cited in the contract documents.
| Standard |
Title |
| IPC |
International Plumbing Code (Chapter 4 — Fixtures and Fixture Fittings; Chapter 7 — Sanitary Drainage, including Section 708 Cleanouts and Section 715 Backwater Valves) |
| UPC |
Uniform Plumbing Code (Chapter 4 — Plumbing Fixtures and Fixture Fittings; Chapter 7 — Sanitary Drainage) |
| ASME A112.6.3 |
Floor and Trench Drains |
| ASME A112.36.2M |
Cleanouts |
| ASME A112.14.1 |
Backwater Valves |
| ASME A112.18.1 / CSA B125.1 |
Plumbing Supply Fittings (hose bibbs, wall hydrants, and supply fittings) |
| ASME A112.18.2 / CSA B125.2 |
Plumbing Waste Fittings (drain bodies, strainers, and waste fittings) |
| ASME A112.1.2 |
Air Gaps in Plumbing Systems (for indirect waste receptors) |
| ASSE 1010 |
Performance Requirements for Water Hammer Arresters |
| ASSE 1011 |
Performance Requirements for Hose Connection Vacuum Breakers |
| ASSE 1017 |
Performance Requirements for Temperature Actuated Mixing Valves for Hot Water Distribution Systems (master mixing valves) |
| ASSE 1018 |
Performance Requirements for Trap Seal Primer Valves — Potable Water Supplied |
| ASSE 1019 |
Performance Requirements for Vacuum Breaker Wall Hydrants, Freeze Resistant, Automatic Draining Type |
| ASSE 1052 |
Performance Requirements for Hose Connection Backflow Preventers |
| ASSE 1070 / ASME A112.1070 / CSA B125.70 |
Performance Requirements for Water Temperature Limiting Devices (point-of-use mixing valves) |
| ASSE 1072 |
Performance Requirements for Barrier-Type Floor Drain Trap Seal Protection Devices |
| PDI WH-201 |
Plumbing and Drainage Institute Standard for Water Hammer Arresters (certification and sizing) |
| NSF/ANSI 61 |
Drinking Water System Components — Health Effects |
| NSF/ANSI/CAN 372 |
Drinking Water System Components — Lead Content |
| ASME A13.1 |
Scheme for the Identification of Piping Systems |
2.2 Precedence
2.2.1Where the contract documents, the Authority Having Jurisdiction (AHJ), or a referenced standard impose conflicting requirements, the more stringent requirement shall govern unless the Engineer of Record directs otherwise in writing.
2.2.2The applicable plumbing code — IPC or UPC as adopted by the jurisdiction — shall take precedence over all other references on any matter the code directly addresses.
2.2.3Where the jurisdiction has adopted the UPC rather than the IPC, references to IPC chapter and section numbers shall be understood to mean the equivalent UPC provisions.
3 Submittals
3.1 Action Submittals
3.1.1Contractor shall submit the following for the Engineer's review and comment prior to procurement and installation of any specialty.
- Product data for cleanouts, organized by access type (floor, wall, grade), identifying the body and plug material, the cover or access material and finish, and the load (duty) rating for floor cleanouts, with compliance to ASME A112.36.2M
- Product data for floor drains and area drains, identifying the body material, the trap arrangement (integral or separate), the grate or strainer type, finish, and load rating, the outlet size and connection, the presence of a sediment bucket where required, and compliance with ASME A112.6.3
- Product data for trap seal protection, identifying water-supplied trap primer valves to ASSE 1018 or barrier-type trap seal protection devices to ASSE 1072, the distribution arrangement, and the backflow protection of any water-supplied primer connection
- Product data for hose bibbs and wall hydrants, identifying the freeze-protection type and the freezeless rough-in (wall) depth, the integral hose-connection backflow protection (ASSE 1011 vacuum breaker or ASSE 1019 freezeless vacuum-breaker wall hydrant), the body material and finish, and NSF/ANSI 61 and NSF/ANSI/CAN 372 certification of wetted parts
- Product data for water hammer arrestors, identifying the PDI WH-201 (or ASSE 1010) certification, the PDI size designation (A through F), and the sealed bellows or piston construction
- Product data for backwater valves, identifying compliance with ASME A112.14.1, the body material, the configuration (horizontal, combination with gate valve, or combination floor drain), and the access provision
- Product data for thermostatic mixing valves, identifying the standard (ASSE 1017 for master distribution mixing valves or ASSE 1070 for point-of-use temperature-limiting valves), the temperature range and setpoint, the failsafe behavior, NSF/ANSI 61 and 372 certification, and the integral checks and strainers
- A water hammer arrestor location and sizing schedule, prepared per PDI WH-201, identifying the fixture-unit load and the arrestor size at each quick-closing-valve location
☑ Cleanout product data with material, finish, and duty rating (ASME A112.36.2M)
☐ Floor and area drain product data with grate, trap, and load rating (ASME A112.6.3)
☐ Trap seal protection product data (ASSE 1018 primer / ASSE 1072 barrier device)
☐ Hose bibb and wall hydrant product data with freeze depth and backflow protection (ASSE 1011 / 1019)
☐ Water hammer arrestor product data (PDI WH-201 / ASSE 1010)
☐ Backwater valve product data (ASME A112.14.1)
☐ Thermostatic mixing valve product data (ASSE 1017 master / ASSE 1070 point-of-use)
☐ Water hammer arrestor location and sizing schedule (PDI WH-201)
3.1.2Work shall not proceed on any specialty group until the corresponding submittals have been reviewed and returned.
3.2 Closeout Submittals
3.2.1Contractor shall provide the following at substantial completion before the plumbing specialties are accepted.
- Operation and maintenance data for trap primer systems, barrier-type trap seal devices, thermostatic mixing valves, and backwater valves, including cleaning, cartridge or element replacement, and setpoint adjustment instructions
- A trap seal protection record identifying every floor drain and its assigned trap seal maintenance method, so that maintenance staff can locate and service each primer or barrier device
- A thermostatic mixing valve commissioning record documenting the as-left setpoint, the measured delivered temperature, and the failsafe verification for each valve
- Manufacturer warranty documentation for floor drains, trap primer units, backwater valves, and mixing valves
- Field test reports for the water hammer arrestor functional check and the backwater valve operation check
☑ Operation and maintenance data for primers, mixing valves, and backwater valves
☑ Trap seal protection record (drain-by-drain maintenance method)
☑ Thermostatic mixing valve commissioning record (setpoint and failsafe)
☑ Manufacturer warranty documentation for specialty items
☑ Field test reports (water hammer arrestor and backwater valve checks)
4 Quality Assurance
4.1 Installer Qualifications
4.1.1Plumbing specialties shall be installed by journeyman plumbers licensed in the jurisdiction where the work is performed and supervised by a licensed plumbing contractor.
4.1.2Thermostatic mixing valves shall be commissioned and set by personnel trained in the calibration of the specific valve, with a calibrated thermometer.
4.2 Lead-Free Compliance
4.2.1All specialty components in contact with potable water — hose bibbs, wall hydrants, trap primer supply connections, and mixing valve wetted parts — shall be certified to NSF/ANSI/CAN 372, confirming that the weighted average lead content of the wetted surface area does not exceed 0.25 percent.
NOTE Lead-free certification under the Reduction of Lead in Drinking Water Act is a federal requirement and is not subject to project-level waiver. (4.2.2)
4.3 Listing and Marking
4.3.1Each specialty shall bear the applicable ASME, ASSE, or PDI designation, the manufacturer's identification, and the model or size rating, legibly marked or cast into the device.
4.3.2Specialties that do not bear the required marking shall not be incorporated into the work.
4.4 Regulatory Inspection Hold Points
4.4.1Floor drains, cleanouts, backwater valves, and trap primer connections that are concealed below slab, behind walls, or above ceilings shall be available for inspection before they are covered.
4.4.2The Contractor shall not enclose any specialty until the applicable rough plumbing inspection has been completed and released.
5 Service Conditions
5.1 Water Supply Pressure
2080
2035456080
Default: 45 psi
Per drawings
5.1.1Hose bibbs, wall hydrants, trap primer valves, and mixing valves shall be selected for the static and flowing supply pressure available at their connection.
NOTE Where building static pressure exceeds 80 psi, a pressure reducing valve shall be provided upstream per
Domestic Water Piping; sustained pressure above 80 psi is prohibited by IPC and UPC and accelerates wear of valve seats and seals.
(5.1.2) 5.2 Freeze Exposure
● Exterior / unconditioned — freezeless wall hydrant required
○ Interior conditioned space — standard hose bibb acceptable
5.2.1Hose bibbs and wall hydrants serving exterior walls, unheated spaces, or any location subject to freezing shall be the freezeless type with the operating seat located inside the heated building envelope.
5.2.2Standard (non-freezeless) hose bibbs shall be used only in conditioned interior locations not subject to freezing.
NOTE A non-freezeless hose connection on an exterior wall traps water in the body where it freezes, expands, and splits the body, and the resulting leak occurs inside the wall where it is not discovered until significant water damage has occurred. (5.2.3)
6 Cleanouts
6.1 General
6.1.1Cleanouts shall be provided at the locations and intervals required by IPC Section 708 (or the equivalent UPC provisions) and as indicated on the drawings, and shall conform to ASME A112.36.2M.
6.1.2Each cleanout shall be the same nominal size as the pipe it serves, up to the maximum size required by code, and shall provide a full-size opening for rodding the drain.
6.1.3Cleanout body and access locations shall be as indicated on the plumbing floor plans. NOTE The cleanout is the only access a maintenance plumber has to clear a blocked drain, and a cleanout that is undersized, buried under finishes, or fitted with a seized plug is functionally absent when it is needed. (6.1.4)
6.2 Cleanout Body and Plug Material
● Cast iron body with cast bronze or brass plug (cast iron piping)
○ Cast iron body with cast iron plug (cast iron piping, concealed)
○ PVC body and plug (PVC DWV piping)
○ ABS body and plug (ABS DWV piping)
6.2.1Cleanout bodies and plugs shall be of a material compatible with the drainage piping they serve.
6.2.2Plugs in cast iron cleanouts shall be cast iron, bronze, or brass; plastic plugs shall not be used in cast iron cleanouts for permanent installation.
6.2.3Plugs in PVC or ABS cleanout fittings shall be of the same plastic, conforming to the fitting manufacturer's specification.
NOTE Plugs shall have a raised nut or recessed-socket head that allows removal with standard plumbing tools, and shall be installed with a thread lubricant or sealant that prevents seizing while permitting later removal. (6.2.4)
6.3 Floor Cleanout Cover Duty Rating
Nickel-bronze top, light-duty — non-traffic finished areas
Nickel-bronze top, medium-duty — pedestrian traffic
Cast iron top, heavy-duty — light vehicular / loading areas
Cast iron top, extra-heavy-duty — forklift and vehicular traffic
Stainless steel top — food service and high-sanitation areas
Per drawings — plumbing fixture/specialty schedule
6.3.1Cleanouts in finished floors shall have a flush cover or access housing rated for the floor loading at that location.
6.3.2The cover shall be set flush with the finished floor surface and shall be of a finish compatible with the floor finish where exposed in occupied space.
NOTE Floor cleanout covers in carpeted areas shall be the carpet-marker (recessed) type that accepts a plug of carpet, and covers in tiled areas shall be the recessed type that accepts the floor tile, where so indicated. (6.3.3)
NOTE Specifying a light-duty cover in a vehicular area produces a cover that cracks under the first wheel load; specifying an extra-heavy-duty cover in a finished lobby is an unnecessary cost and an aesthetic intrusion, so the duty rating shall match the actual floor loading. (6.3.4)
6.4 Wall Cleanouts
6.4.1Wall cleanouts shall be provided with a chrome-plated or stainless steel access cover and a securing screw at the finished wall face.
6.4.2Cleanouts located in concealed spaces shall be provided with an access panel labeled "PLUMBING CLEANOUT" on the visible face, sized to permit insertion of rodding equipment.
6.5 Cleanout Clearance
6.5.1Each cleanout shall have not less than 18 inches of clear working space directly in front of the opening for drain-cleaning equipment to enter, and cleanouts 6 inches and larger shall have not less than 24 inches of clearance.
6.5.2Cleanouts shall not be installed where the clearance or the direction of rodding does not permit the cleaning tool to enter the drain in the direction of flow.
7 Floor and Area Drains
7.1 General
● Cast iron with coated interior (commercial / institutional standard)
○ Stainless steel (food service, healthcare, high-sanitation)
○ Nickel-bronze (architectural exposed locations)
○ PVC (light-duty utility spaces only)
7.1.2Drain body sizes, outlet sizes, grate types, and finishes shall be as indicated on the plumbing floor plans and the specialty schedule. NOTE Cast iron drain bodies are the standard for commercial and institutional construction; stainless steel is used in food service, healthcare, and high-sanitation areas; and PVC is acceptable only in lightly loaded utility spaces. (7.1.3)
7.2 Grate Duty Rating
Light-duty — non-traffic mechanical and storage areas
Medium-duty — pedestrian traffic in occupied areas
Heavy-duty — light vehicular and cart traffic
Extra-heavy-duty — forklift and vehicular traffic, ductile iron
Per drawings — plumbing fixture/specialty schedule
7.2.1The grate or strainer shall be rated for the live load imposed at its location, and grates in areas subject to wheeled vehicle traffic shall be rated for the applicable vehicular load.
7.2.2Grates in areas accessible to the public shall be secured against accidental displacement, and grates in food service and healthcare areas shall be removable without tools for cleaning.
NOTE The drain body and grate shall be set level and flush with the finished floor; a drain set proud of the floor is a trip hazard and prevents effective floor mopping, and a drain set low ponds water around it. (7.2.3)
7.3 Sediment Bucket
○ Provided — kitchens, food service, and areas with solids-laden discharge
● Not provided — clean-water areas (mechanical rooms, restrooms)
7.3.1Floor drains in kitchens, food service areas, and other locations receiving solids-laden discharge shall be furnished with a removable sediment bucket that intercepts solids before they enter the drainage system.
7.3.2The sediment bucket shall be removable for cleaning without tools and shall be of the same corrosion-resistant material as the drain body.
7.4 Area Drains
7.4.1Area drains serving courtyards, areaways, ramps, and similar exterior or semi-exterior surfaces shall be provided with a deep sump and a heavy-duty grate sized for the design surface drainage flow.
7.4.2Area drains that may receive debris shall be furnished with a sediment bucket or a debris dome, and area drains subject to vehicular traffic shall be rated for the vehicular load.
NOTE Area drains connected to the sanitary system shall be trapped and trap-seal-protected; where the drainage is storm water, the connection is governed by
Roof Drainage and the site storm scope, not this standard.
(7.4.3) 8 Trap Seal Protection
8.1 General
8.1.1Every floor drain trap and every infrequently used trap shall be provided with a means of maintaining the trap seal against evaporation, so that the water seal continues to block sewer gas from entering occupied space.
NOTE Failure to maintain trap seals allows sewer gas (hydrogen sulfide) to enter occupied spaces and is one of the most commonly cited plumbing deficiencies in occupied buildings; the protection is cheap and the failure is both unpleasant and a health concern, so it shall not be omitted on infrequently used drains. (8.1.2)
8.2 Trap Seal Maintenance Method
Frequent-use drain — no primer required (document basis in submittals)
Water-supplied trap seal primer valve (ASSE 1018)
Barrier-type trap seal protection device (ASSE 1072)
Electronic / distribution trap primer serving multiple drains
8.2.1Floor drains subject to regular water discharge — in mechanical rooms with equipment drains, in restrooms, and in service corridors receiving mop sink discharge — may rely on that regular discharge to maintain the trap seal, and the basis shall be documented in the submittals.
8.2.2Floor drains that are infrequently used — in storage rooms, electrical rooms, elevator pits, and similar spaces — shall be provided with a trap seal primer system or a listed barrier-type trap seal protection device.
8.3 Water-Supplied Trap Primers
8.3.1Water-supplied trap seal primer valves shall conform to ASSE 1018 and shall discharge to the inlet side of the trap, above the water seal, through a connection that prevents back-siphonage.
8.3.2The primer valve shall be connected to the domestic cold water system with backflow protection in accordance with Domestic Water Piping and the adopted plumbing code. 8.3.3Where one primer serves multiple drains through a distribution unit, the distribution unit shall be a listed device that proportions the priming water to each connected trap.
NOTE The primer connection shall be accessible for service, and a primer concealed above a hard ceiling shall be provided with an access panel. (8.3.4)
8.4 Barrier-Type Trap Seal Devices
8.4.1Barrier-type trap seal protection devices conforming to ASSE 1072 are acceptable where a water supply connection to the drain is not practical.
8.4.2The barrier device shall be installed in the trap inlet per the manufacturer's instructions and shall be maintained or replaced on the schedule the manufacturer recommends.
NOTE A barrier-type device uses a flexible membrane or float that opens under drainage flow and closes to block sewer gas when the drain is idle, providing trap seal protection without a water connection; it is the preferred solution where running a primer water line to an isolated drain would be disproportionately costly. (8.4.3)
9 Hose Bibbs and Wall Hydrants
9.1 General
9.1.1Hose bibbs and wall hydrants shall conform to ASME A112.18.1 / CSA B125.1, and all wetted parts shall be certified to NSF/ANSI 61 and NSF/ANSI/CAN 372.
NOTE Every hose connection — hose bibb, wall hydrant, and service-sink faucet hose outlet — shall be protected against backflow, because a hose submerged in a contaminant (a mop bucket, a chemical tank, a pool) is a direct cross-connection to the potable supply. (9.1.2)
9.2 Hose Connection Backflow Protection
● Integral ASSE 1019 freezeless vacuum-breaker wall hydrant (exterior freezeless)
○ Integral ASSE 1011 hose connection vacuum breaker (interior hose bibb)
○ ASSE 1052 hose connection backflow preventer (continuous-pressure / higher-hazard hose use)
9.2.1Interior hose bibbs shall be provided with a hose connection vacuum breaker conforming to ASSE 1011, integral to the device or installed on the outlet and secured against removal.
9.2.2Freezeless wall hydrants on exterior walls shall be the vacuum-breaker, freeze-resistant, automatic-draining type conforming to ASSE 1019.
9.2.3Where a hose is left under continuous pressure or is used in a higher-hazard connection, a hose connection backflow preventer conforming to ASSE 1052 shall be provided in lieu of an atmospheric vacuum breaker.
NOTE An ASSE 1011 vacuum breaker protects only against back-siphonage and must not be left under continuous pressure, whereas an ASSE 1019 wall hydrant and an ASSE 1052 backflow preventer protect against both back-siphonage and back-pressure and tolerate a hose left connected and pressurized. (9.2.4)
9.3 Freezeless Wall Hydrant Rough-In Depth
4 in (thin wall, mild climate)
6 in
8 in
10 in
12 in
14 in (thick / insulated wall, cold climate)
Per drawings — plumbing fixture/specialty schedule (deferred by default)
9.3.1The barrel length of a freezeless wall hydrant shall be selected so that the operating seat is located inside the heated building envelope, past the wall insulation, for the wall thickness at the installation location.
9.3.2The hydrant shall be installed pitched downward toward the outlet so that it drains completely when closed, as required for the automatic-draining function.
NOTE A freezeless hydrant whose barrel is too short places the seat within the wall or the insulation, where the water in the closed body still freezes; selecting the barrel length to the actual wall thickness is the entire basis of the freeze protection. (9.3.3)
NOTE Box Hydrants and Yard Hydrants (9.4)
9.4.1Recessed box hydrants with a hinged, lockable cover shall be used where a flush exterior wall face is required, and shall be the freezeless type where subject to freezing.
10 Water Hammer Arrestors
10.1 General
10.1.1Water hammer arrestors shall conform to PDI WH-201 or ASSE 1010 and shall be the sealed, permanently charged bellows or piston type.
NOTE Air-chamber stubs (capped pipe air chambers) shall not be used in lieu of listed arrestors, because an air chamber waterlogs over time and loses its cushioning effect. (10.1.2)
NOTE Water hammer is the pressure spike produced when flow is stopped abruptly; the spike hammers pipe joints, fittings, and valve seats and produces the characteristic banging, and over time it loosens joints and fails connections, so it shall be arrested at its source. (10.1.3)
10.2 Location
10.2.1A water hammer arrestor shall be installed at every quick-closing valve, including solenoid valves, sensor faucets and flushometers, clothes-washer and dishwasher connections, and any other valve that closes in a fraction of a second.
10.2.2The arrestor shall be installed as close as practical to the quick-closing valve, and on a branch serving multiple fixtures it shall be located at the end of the branch between the last two fixtures.
10.2.3Where a branch line from the start of the horizontal branch to the last fixture supply exceeds 20 feet, an additional arrestor shall be installed.
NOTE Arrestors installed in concealed locations shall be installed without an access requirement only where they are the sealed, maintenance-free listed type; air chambers requiring recharge are not permitted in concealed locations. (10.2.4)
10.3 Sizing
PDI Size A (1 to 11 fixture units)
PDI Size B (12 to 32 fixture units)
PDI Size C (33 to 60 fixture units)
PDI Size D (61 to 113 fixture units)
PDI Size E (114 to 154 fixture units)
PDI Size F (155 to 330 fixture units)
Per drawings — water hammer arrestor sizing schedule (deferred by default)
10.3.1Water hammer arrestors shall be sized by the fixture-unit method of PDI WH-201 for the load downstream of the quick-closing valve they serve.
10.3.2The Contractor shall prepare a water hammer arrestor location and sizing schedule identifying the fixture-unit load and the PDI size at each location, and shall submit it for the Engineer's review.
NOTE Undersizing the arrestor leaves residual water hammer, and a single small arrestor cannot protect a large branch; the fixture-unit method matches the arrestor's absorption capacity to the energy of the arrested flow. (10.3.3)
11 Backwater Valves
11.1 General
11.1.1Backwater valves shall conform to ASME A112.14.1 and shall have a body of cast iron, plastic, or copper alloy with a noncorrosive seat and a self-aligning, positively sealing disc.
NOTE A backwater valve shall be provided where required by IPC Section 715 (or the equivalent UPC provision) to protect fixtures from sewer backflow during a surcharge of the building sewer or public sewer. (11.1.2)
11.2 Application
○ Required — fixtures with flood-level rims below the next upstream manhole rim
● Not required — all fixtures discharge above the next upstream manhole rim
11.2.1A backwater valve shall be installed in the branch or drain serving only those fixtures whose flood-level rims are below the elevation of the next upstream manhole cover in the public sewer.
11.2.2Fixtures with flood-level rims above the next upstream manhole rim shall not discharge through the backwater valve, so that those fixtures continue to drain by gravity if the protected valve is closed during a surcharge.
NOTE A backwater valve placed in the main building drain serving all fixtures is a common error: during a sewer surcharge it closes and blocks every fixture from draining, including those that did not need protection, so the valve shall protect only the below-rim fixtures. (11.2.3)
11.3 Access
11.3.1Every backwater valve shall be installed in an accessible location with an access cover or an access panel that permits inspection, cleaning, and servicing of the valve disc and seat.
11.3.2A backwater valve installed below a slab shall be provided with a cleanout-style access housing brought flush to the finished floor, and a valve above a hard ceiling shall be provided with an access panel.
NOTE A backwater valve that cannot be reached cannot be inspected or cleared, and a disc fouled by debris seals against neither flow nor backflow; access is mandatory, not optional. (11.3.3)
12 Thermostatic Mixing Valves
12.1 General
NOTE Thermostatic mixing valves shall be selected for their function — master mixing for hot water distribution, or point-of-use temperature limiting at a fixture or fixture group — and shall conform to the standard that matches that function. (12.1.1)
12.1.2All mixing valve wetted parts shall be certified to NSF/ANSI 61 and NSF/ANSI/CAN 372.
NOTE Mixing valves serving fixtures shall be coordinated with
Water Heaters for the stored hot water temperature and the system recirculation temperature, and with
Plumbing Fixtures for the fixture-level scald protection.
(12.1.3) 12.2 Valve Standard by Function
○ ASSE 1017 master mixing valve — at the water heater / distribution source
● ASSE 1070 point-of-use temperature-limiting valve — at fixture or fixture group
12.2.1Master mixing valves located at the water heater or the source of hot water distribution shall conform to ASSE 1017.
12.2.2Point-of-use temperature-limiting valves serving an individual fixture or a group of fixtures shall conform to ASSE 1070.
NOTE An ASSE 1017 master mixing valve reduces stored hot water (held at 140°F or higher to suppress Legionella) to a safe distribution temperature of approximately 120°F, but it is not a substitute for fixture-level scald protection and shall not be used to deliver water directly to a user; an ASSE 1070 valve provides the final scald limit at the fixture. (12.2.3)
12.3 Master Mixing Valve Setpoint
105130
110115120125130
Default: 120 °F
12.3.1The master mixing valve shall be set to deliver hot water to the distribution system at the temperature required by the contract documents, typically 120°F, while the upstream storage temperature is maintained high enough for Legionella control.
12.3.2The master mixing valve shall be the failsafe type that limits or shuts off the outlet on loss of the cold supply, so that it cannot pass full-temperature stored water to the distribution system.
12.4 Point-of-Use Setpoint
110°F (public lavatories — IPC / UPC limit)
105°F (healthcare, childcare, schools — enhanced scald protection)
12.4.1The point-of-use temperature-limiting valve shall be set so that the delivery temperature at the fixture does not exceed the limit established by the adopted plumbing code, which is 110°F for public-use lavatories.
12.4.2Healthcare, childcare, and school applications shall be set to a 105°F maximum delivery temperature.
NOTE The point-of-use valve shall be the failsafe type that limits the outlet temperature on loss of the cold supply, protecting the user from a sudden scald. (12.4.3)
12.5 Valve Trim
12.5.1Each mixing valve shall be furnished with inlet checks to prevent crossover between the hot and cold supplies, inlet strainers to protect the thermostatic element from debris, and integral or accessible isolation stops.
NOTE A mixing valve installed without inlet checks allows hot water to migrate into the cold line and cold into the hot, defeating the temperature control and producing warm cold water at every fixture on the branch. (12.5.2)
13 Access and Identification
13.1 Access
13.1.1Every specialty requiring inspection, cleaning, adjustment, or service — cleanouts, backwater valves, trap primers, mixing valves, and concealed arrestors that are not the sealed maintenance-free type — shall be accessible after construction is complete.
13.1.2Specialties concealed above hard ceilings or behind finished walls shall be provided with an access panel sized for service and labeled to identify the concealed device.
NOTE Access panels in rated assemblies shall be of a fire-resistance rating matching the assembly and shall be a listed rated access door. (13.1.3)
13.2 Identification
13.2.1Concealed-device access panels shall be labeled on the visible face to identify the device behind them (for example, "PLUMBING CLEANOUT," "BACKWATER VALVE," or "MIXING VALVE").
13.2.2Mixing valves shall be tagged with the as-left setpoint and the valve standard, so that maintenance staff do not adjust a code-limited scald valve above its limit.
13.2.3Specialty water connections in mechanical rooms shall be identified with pipe markers conforming to ASME A13.1 indicating the contents and direction of flow.
14 Installation
14.1 General
14.1.1The Contractor shall install each specialty in accordance with this standard, the approved submittals, the manufacturer's instructions, and the adopted plumbing code.
14.1.2Specialties shall be installed plumb, level, and at the elevations and orientations required for their function — floor drains and cleanouts flush with finished floor, freezeless hydrants pitched to drain, and backwater valves oriented for the direction of flow.
14.1.3Dimensions and elevations that cannot be confirmed from the drawings shall be referred to the Engineer of Record before the specialty is set or concealed.
14.2 Coordination
14.2.1Floor drain, area drain, and cleanout rough-in shall be coordinated with the structural slab, the floor finish, and the drainage piping so that bodies are set at the correct elevation before the slab is poured.
14.2.2Wall hydrant and hose bibb rough-in shall be coordinated with the wall construction and insulation so that the freezeless barrel length is correct for the as-built wall thickness.
14.2.3Mixing valve and trap primer connections shall be coordinated with the domestic water piping and located for accessibility before walls and ceilings are closed.
NOTE Where a specialty of one metal connects to piping of a dissimilar metal in a wet location, a dielectric union or an approved dielectric connection shall be used to prevent galvanic corrosion. (14.3.1)
15 Testing
15.1 General
15.1.2Each specialty shall additionally be functionally checked as described below before acceptance.
15.2 Functional Checks
☑ Cleanout plugs verified removable and reseated
☑ Floor and area drains verified to drain and hold trap seal
☑ Trap primers verified to discharge priming water to the trap
☑ Wall hydrants verified to operate and to drain (freezeless function)
☑ Water hammer arrestors verified by operating the served quick-closing valve
☑ Backwater valve disc verified free and seating
☑ Mixing valve delivered temperature verified at the setpoint
15.2.1Each cleanout plug shall be verified to remove with standard tools and shall be reseated with thread lubricant.
15.2.2Each trap primer shall be verified to discharge priming water to its assigned trap, and each protected trap shall be confirmed to hold a seal.
15.2.3Each freezeless wall hydrant shall be operated and verified to shut off and to drain completely when closed.
15.2.4Each water hammer arrestor shall be verified by operating the served quick-closing valve and confirming the absence of audible hammer.
15.2.5Each backwater valve shall be opened and the disc verified to move freely and to seat against backflow.
15.2.6Each thermostatic mixing valve shall be commissioned with a calibrated thermometer, set to the required delivery temperature, and verified to limit or shut off on simulated loss of the cold supply.
16 Delivery, Storage, and Handling
16.1Specialties shall be delivered in the manufacturer's original packaging with identification and rating markings intact and legible.
16.2Cast iron drain and cleanout bodies shall be inspected for cracks and damaged hubs on delivery, and damaged bodies shall not be installed.
NOTE Mixing valve thermostatic elements, trap primer valves, and backwater valve discs shall be kept clean and protected from construction debris until installed, because grit in a thermostatic element or under a backwater disc prevents it from functioning correctly. (16.3)
16.4Finished cleanout covers, grates, and hydrant trim shall be stored protected and shall be installed after the floor and wall finishes are complete where practical, to avoid damage during construction.
17 Warranty
1 year from substantial completion
2 years from substantial completion
17.1The Contractor shall warrant all specialties and their installation against defects in workmanship and against leakage for the project warranty period following substantial completion.
17.2Manufacturer warranties for floor drain bodies, trap primer valves, backwater valves, and mixing valves shall be passed through to the Owner as part of the closeout documentation.
17.3Where a manufacturer warranty extends beyond the Contractor's installation warranty period, the Contractor shall assign and transfer the manufacturer warranty to the Owner at closeout.
NOTE A specialty that does not leak but was installed with the wrong duty rating, an incorrect freezeless barrel length, an undersized arrestor, a backwater valve serving fixtures it should not, or a mixing valve set above its code limit shall be corrected at the Contractor's expense if the deficiency is discovered within the warranty period. (17.4)