Safety devices, relief valves & temperature controls

Grounded in the retrieved California Plumbing Code — click a citation to read the verbatim passage:

• CPC § 54-2018 High relevance — show source text

  Clearance for unlisted water heaters shall be not less than 12 inches (305 mm) on all sides. Combustible floors under unlisted water heaters shall be protected in an approved manner. {NFPA 54-2018:10.27.2.2} 504.4 Pressure-Limiting Devices. A water heater installation shall be provided with overpressure protection using an approved, listed device installed in accordance with the terms of its listing and the manufacturer’s installation instructions. Pressure relief devices shall have a pressure setting greater than the water service pressure and not exceed 150 psi (1034 kPa) as required in Section 608.4. 504.5 Temperature Limiting Devices. A water heater installation or a hot water storage vessel installation shall be provided with overtemperature protection by means of an approved, listed device installed in accordance with the terms of its listing and the manufacturer’s installation instructions. {NFPA 54:10.26.5} 504.6 Temperature, Pressure, and Vacuum Relief Devices. Temperature, pressure, and vacuum relief devices or combinations thereof, and automatic gas shutoff devices shall be installed in accordance with the terms of their listings and the manufacturer’s installation instructions. A shutoff valve shall not be placed between the relief valve and the water heater or on discharge pipes between such valves and the atmosphere. The hourly British thermal units (Btu) (kW•h) discharge capacity or the rated steam relief capacity of the device shall be not less than the input rating of the water heater. {NFPA 54:10.26.6} Discharge piping shall be installed in accordance with Section 608.5.

  504.7 Lead Content. Water heaters shall comply with the lead content requirements of Section 604.2.

  505.0 Oil-Burning and Other Water Heaters. 505.1 Water Heaters. Water heaters deriving heat from fuels or types of energy other than gas shall comply with the standards referenced in Table 501.1(1), Section 505.3, or Section 505.4. Vents or chimneys for such appliances shall be of approved types. An adequate supply of air for combustion and for adequate ventilation of heater rooms or compartments shall be provided. Each such appliance shall be installed in a

  location approved by the Authority Having Jurisdiction and local and state fire-prevention agencies. 505.2 Safety Devices. Storage-type water heaters and hot water boilers deriving heat from fuels or types of energy other than gas, shall be provided with, in addition to the primary temperature controls, an over-temperature safety protection device that complies with and is installed in accordance with nationally recognized applicable standards for such devices and a combination temperature and pressure-relief valve.

  505.3 Oil-Fired Water Heaters. Oil-fired water heaters

  shall be installed in accordance with NFPA 31.

  505.4 Indirect-Fired Water Heaters. Indirect-fired water heaters shall be in accordance with the applicable sections of the ASME Boiler and Pressure Vessel Code or shall comply with one of the other applicable standards shown in Table 501.1(1). Each water heater shall bear a label in accordance with ASME requirements, or an approved testing agency, certifying and attesting that such an appliance has been tested, inspected and meets the requirements of the applicable standards or code. 505.4.1 Single-Wall Heat Exchanger. An indirectfired water heater that incorporates a single-wall heat exchanger shall be in accordance with the following requirements:

• CPC § 505.0 High relevance — show source text

  Oil-burning and other . . . . . . . . . . . . . . . . . . . . . .505.0 Permits required . . . . . . . . . . . . . . . . . . . . . . . . . .502.0

  Pressure-relief valves . . . . . . . . . . .504.4, 504.6, 505.2,

  608.2 – 608.5

  Protection . . . . . . . . . . . . . . . . . . .504.3 – 504.6, 505.2,

  507.2, 507.8, 507.10,

  507.14.1, 507.24

  Relief valve discharge . . . . . . . . . . . . . . . . . . . . . .608.5 Seismic provisions . . . . . . . . . . . . . . . . . . . . . . . . .507.2 Temperature and pressure-relief valves . . . . . . . . . . . . . . .504.6, 505.2 Temperature-limiting devices . . . . . . . . . . . . . . . . .504.5

  Vents . . . . . . . . . . . . . . . . . . . . . . . . . . . . .509.0, 510.0

  Water heating system requirements . . . . . . . . . . . .501.2 WATER SOFTENERS . . . . . . . . . . . . . . . . 611.4, Table 611.4

  WATER STATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . .225.0

  WATER TESTS

  Building sewers . . . . . . . . . . . . . . . . . . . . . . . . . . .723.0 Drainage and vent systems . . . . . . . . . . . . .105.3, 712.2 Storm drainage . . . . . . . . . . . . . . . . . .1107.2.1, 1107.2.3 Water supply systems . . . . . . . .105.2.1.1, 105.3, 609.4

  WATERPROOFING

  AND WATERTIGHT

  Building sewer . . . . . . . . . . . . . . . . . . . . . . . . . . . .723.1

  Cleanouts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .707.3

  Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . .105.3

  Drain pans . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .507.5

  Fixtures . . . . . . . . . . . . . . . . .402.2, 408.6, 408.8, 418.2

• CPC § 904.5 High relevance — show source text

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  INSTALLATION OF SPECIFIC APPLIANCES

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  904.5 Temperature or Pressure Limiting Devices. Steam and hot water boilers, respectively, shall be provided with approved automatic limiting devices for shutting down the burner(s) to prevent boiler steam pressure or boiler water temperature from exceeding the maximum allowable working pressure or temperature. Safety limit controls shall not be used as operating controls. [NFPA 54:10.3.5]

  904.6 Low-Water Cutoff. All water boilers and steam boilers shall be provided with an automatic means to shut off the fuel supply to the burner(s) if the boiler water level drops below the lowest safe water line. In lieu of the low-water cutoff, water tube or coil-type boilers that require forced circulation to prevent overheating and failure shall have an approved flow sensing device arranged to shut down the boiler when the flow rate is inadequate to protect the boiler against overheating. [NFPA 54:10.3.6]

  904.7 Steam Safety and Pressure Relief Valves. Steam and hot water boilers shall be equipped, respectively, with listed or approved steam safety or pressure relief valves of appropriate discharge capacity and conforming with ASME requirements. A shutoff valve shall not be placed between the relief valve and the boiler or on discharge pipes between such valves and the atmosphere. [NFPA 54:10.3.7]

  904.7.1 Discharge. Relief valves shall be piped to discharge near the floor. [NFPA 54:10.3.7.1]

  904.7.2 Size. The entire discharged piping shall be at least the same size as the relief valve discharge piping.

  [NFPA 54:10.3.7.2]

  904.7.3 End Connections. Discharge piping shall not contain threaded end connection at its termination point.

  [NFPA 54:10.3.7.3]

  904.8 Refrigeration Coils. The installation of refrigeration coils shall comply with the following requirements:

  (1) A refrigeration coil shall not be installed in conjunction with a forced air furnace where circulation of cooled air is provided by the furnace blower, unless the blower has

  sufficient capacity to overcome the external static pressure resistance imposed by the duct system and refrigeration coil at the air flow rate for heating or cooling, whichever is greater.

  (2) Furnaces shall not be located upstream from refrigeration coils, unless the refrigeration coil is designed or equipped so as not to develop excessive temperature or

  pressure.

  (3) Refrigeration coils shall be installed in parallel with or on the downstream side of central furnaces to avoid condensation in the heating element, unless the furnace has been specifically listed for downstream installation. With a parallel flow arrangement, the dampers or other means used to control flow of air shall be sufficiently tight to prevent any circulation of cooled air through the furnace.

  (4) Means shall be provided for disposal of condensate and to prevent dripping of condensate on the heating element.

  [NFPA 54:10.3.9]

  904.9 Cooling Units Used with Heating Boilers. Boilers, where used in conjunction with refrigeration systems, shall be installed so that the chilled medium is piped in parallel with the heating boiler with appropriate valves to prevent the chilled medium from entering the heating boiler.

• CPC § 507.25 High relevance — show source text

  507.25, 508.4

  Approval requirements . . . . . . . . . . . . . . . . . . . . . .501.1 Approved standards . . . . . .Table 501.1(1), 505.3, 505.4 Clearances. . . . . . . . . . . . . . . . . . . . . . 504.3 – 504.3.2,

  508.1, 508.2.1

  Combustion air required . . . . . . . . . . . . . . . . . . . .506.0

  Connectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . .604.13

  Dual purpose, definition . . . . . . . . . . . . . . . . . . . .225.0

  Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .225.0

  Garages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .507.13 Inspections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .503.2

  Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .507.0

  Location . . . . . . . . . . . . . . . . . . .504.1, 507.12 – 507.15

  Oil-burning and other . . . . . . . . . . . . . . . . . . . . . .505.0 Permits required . . . . . . . . . . . . . . . . . . . . . . . . . .502.0

  Pressure-relief valves . . . . . . . . . . .504.4, 504.6, 505.2,

  608.2 – 608.5

  Protection . . . . . . . . . . . . . . . . . . .504.3 – 504.6, 505.2,

  507.2, 507.8, 507.10,

  507.14.1, 507.24

  Relief valve discharge . . . . . . . . . . . . . . . . . . . . . .608.5 Seismic provisions . . . . . . . . . . . . . . . . . . . . . . . . .507.2 Temperature and pressure-relief valves . . . . . . . . . . . . . . .504.6, 505.2 Temperature-limiting devices . . . . . . . . . . . . . . . . .504.5

  Vents . . . . . . . . . . . . . . . . . . . . . . . . . . . . .509.0, 510.0

  Water heating system requirements . . . . . . . . . . . .501.2 WATER SOFTENERS . . . . . . . . . . . . . . . . 611.4, Table 611.4

• CPC § 1102.3 High relevance — show source text

  Chapter 10 Boilers and Pressure Vessels. Chapter 10 regulates the construction, installation, operation, repair, and alteration of boilers and pressure vessels. The safety provisions within this chapter address controls and limit devices for automatic boilers, methods of determining expansion tank capacities, discharge piping, relief valves, shutoff valves, gas-pressure and combustion regulators, and inspections and tests. Potable water heaters are free from the requirements of Chapter 10 as they are within the scope of the Uniform Plumbing Code (UPC).

  Pressure vessels store large amounts of energy and must comply with ASME Boiler and Pressure Vessel Code (BPVC) Section VIII.1. The stored energy must be contained to prevent disastrous failures. Boilers must comply with ASME BPVC Section I, ASME BPVC Section IV, or NFPA 85. Installing a safety relief valve and expansion tank prevents pressures in the tank from exceeding the design threshold.

  Chapter 11 Refrigeration. Chapter 11 regulates the design, installation, and construction requirements of refrigeration systems and the installation and construction of cooling towers. Refrigeration is a method used for achieving heat transfer to cool spaces. Refrigerants are the most common medium used to transfer the heat energy from the low-temperature level to the high-temperature level. Table

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  FORMAT OF THE UNIFORM MECHANICAL CODE

  1102.3 lists the most commonly used refrigerants and is labeled by a number. The concentration limits provided in Table 1102.3 are useful for the quantity of refrigerant required to cool a volume of space safely.

  A major milestone reached in the industry was the introduction of lower flammability refrigerants such as A2L and B2L. The industry’s concerns to address lower Global Warming Potential (GWP) refrigerants led to the development of these lower flammability refrigerants. Chapter 11 does not only include these lower flammability refrigerants in Table 1102.3, but it also contains specific A2L and B2L provisions to address the precautions necessary for the proper use of these products. In particular, high-probability systems using A2L refrigerants for human comfort applications are covered by provisions which include refrigerant concentration limits, mechanical ventilation, ignition sources, compressors and pressure vessels, and refrigerant sensors.

  In addition, Chapter 11 addresses other minimum requirements for refrigeration systems such as refrigeration machinery rooms (including ventilation), relief valves, and pressure vessels. Apart from refrigerants, the chapter also addresses minimum requirements for systems that use other mediums such as ammonia and brine systems. For ammonia systems, such systems are required to comply with IIAR 2, IIAR 3, IIAR/ANSI 4, IIAR 5, and IIAR 6.

  Chapter 12 Hydronics. Chapter 12 regulates hydronic systems that are part of heating, cooling, ventilation, and conditioning systems. Such piping systems include steam, hot water, radiant heating and cooling, chilled water, steam condensate, condenser water, ground source heat pump systems, snow and ice melt systems, ambient temperature loops, and district ambient temperature loops. Provisions within this chapter addressing ground source heat pumps and ambient temperature loops apply to the hydronic portions of the system. Geothermal energy systems, including ground source heat pumps and ambient temperature loops, are regulated by Chapter 17.

• CPC § 3663.3 High relevance — show source text

  (j) One high oil or liquid fuel-pressure interlock, reset from flame safeguard or manually.

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  APPENDIX C

  (k) Where hot water or steam, two low water cutoffs.

  (l) An atomizing medium proving switch.

  (m) A low oil temperature switch for oil or liquid fuel requiring preheating.

  (n) A high oil temperature interlock for oil or liquid fuel requiring preheating.

  (o) The burner oil pump shall automatically not operate or rotate while the alternate fuel is firing.

  (p) A pressure-relief valve shall be provided between safety shutoff valves and between pump and safety valves where an integral valve is used with a pump.

  (q) A separate relief device is required on each transfer

  pump.

  (r) One low oil or liquid fuel-pressure interlock, reset from flame safeguard or manually.

  (s) Burners with automatic controls, prepurge, proofof-closure, modulation, or postpurge shall not use relays external to the flame safeguard to accomplish these functions.

  (4) Two million five hundred thousand to 12 499 999 Btu/h (733 kW to 3663.3 kW) per burner.

  (a) One approved manual shutoff valve lever handle.

  (b) One approved fuel-oil filter, installed on the supply piping.

  (c) Two safety shutoff valves in series, with a combined flame failure response and valve closing time not to exceed 5 seconds with strainer directly before the valves.

  (d) Programmed electronic flame safeguard including proven low-fire start, manual reset lockout, 100 percent shutoff (both pilot and main burner), and a separately supervised and proven pilot.

  Flame-sensing systems utilizing a UV scanner shall prove pilot and interrupt ignition spark prior to main burner valves being energized.

  (e) Two controls, one operating and one high limit, activated by temperature or pressure.

  (f) Burners relying on mechanical means to provide air for combustion shall have actual proof-of-air interlock device.

  (g) Power burners shall include proven prepurge of not less than 60 seconds at high-fire damper settings. This prepurge shall occur before every burner cycle, regardless of reason.

  (h) Installations with dampered combustion air openings shall prove damper open position before trial for burner ignition.

  (i) Vent dampers and flue dampers shall be interlocked to prevent burner ignition unless safely open.

  (j) One high oil or liquid fuel-pressure interlock, reset from flame safeguard or manually.

  (k) Where hot water or steam, two low water cutoffs.

  (l) An atomizing medium proving switch.

  (m) A low oil temperature switch for oil or liquid fuel requiring preheating.

  (n) A high oil temperature interlock for oil or liquid fuel requiring preheating.

  (o) A separate firing rate control valve.

  (p) The burner oil pump shall automatically not operate or rotate while the alternate fuel is firing.

  (q) A pressure-relief valve shall be provided between safety shutoff valves and between pump and safety valves where an integral valve is used with a pump.

  (r) A separate relief device is required on each transfer

  pump.

  (s) One low oil or liquid fuel-pressure interlock reset from flame safeguard or manually.

• CPC § 1205.3 High relevance — show source text

  Note: [HCD 1 & HCD 2] PEX-AL-PEX is not adopted in the California Plumbing Code for use in potable water supply and distribution systems. (2) Copper tubing shall be tested at not less than 80 psi (552 kPa). 1205.3 Flushing. Heating and cooling sources, system piping and tubing shall be flushed after installation with water or a cleaning solution. Cleaning and flushing of the heating and cooling sources shall comply with the manufacturer’s instructions. The cleaning solution shall be compatible with all system components and shall be used in accordance with the manufacturer’s instructions.

  1206.0 Pressure and Safety Devices. 1206.1 General. Each closed hydronic system shall be protected against pressures exceeding design limitations with not less than one pressure relief valve. Each closed section of the system containing a heat source shall have a relief valve located so that the heat source is not capable of being isolated from a relief device. Pressure relief valves shall be installed in accordance with their listing and the manufacturer’s installation instructions.

  1206.2 Discharge Piping. The discharge piping serving a temperature relief valve, pressure relief valve, or combination of both shall have no valves, obstructions, or means of isolation and be provided with the following: (1) Not less than the size of the valve outlet and shall discharge full size to the flood level of the area receiving the discharge and pointing down. (2) Materials shall be rated at not less than the operating temperature of the system and approved for such use or shall comply with ASME A112.4.1. (3) Discharge pipe shall discharge independently by gravity through an air gap into the drainage system or outside of the building with the end of the pipe not exceeding 2 feet (610 mm) and not less than 6 inches (152 mm) above the ground and pointing downwards. (4) Discharge in such a manner that does not cause personal injury or structural damage. (5) No part of such discharge pipe shall be trapped or subject to freezing. (6) The terminal end of the pipe shall not be threaded. (7) Discharge from a relief valve into a water heater pan shall be prohibited.

  (8) The discharge termination point shall be readily visible.

  1207.0 Heating Appliances and Equipment. 1207.1 General. Heating appliances, equipment, safety and operational controls shall be listed for its intended use in a hydronic heating system and installed in accordance with the manufacturer’s installation instructions.

  1207.2 Boilers. Boilers and their control systems shall comply with Section 1002.0. 1207.2.1 Condensing Boilers. A condensing boiler, in which the heat exchanger and venting system are designed to operate with condensing flue gases, shall be permitted to be connected directly to the panel heating system without a protective mixing device. 1207.2.2 Noncondensing Boilers. Where the heat exchanger and venting system are not designed to operate with condensed flue gases, the boiler shall be permitted to connect directly to the panel heating system where protected from flue gas condensation. The operating temperature of the boiler shall be more than the fluid temperature in accordance with the manufacturer’s instructions. The minimum return-water temperature to the heat source shall comply with Section 1201.5.

• CPC § 3663.3 High relevance — show source text

  (n) A high oil temperature interlock for oil or liquid fuel requiring preheating.

  (o) The burner oil pump shall automatically not operate or rotate while the alternate fuel is firing.

  (p) A pressure-relief valve shall be provided between safety shutoff valves and between pump and safety valves where an integral valve is used with a pump.

  (q) A separate relief device is required on each transfer

  pump.

  (3) One million to 2 499 999 Btu/h (293 kW to 732 kW) input per burner.

  (a) One approved manual shutoff valve lever handle.

  (b) One approved fuel-oil filter, installed on the supply piping.

  (c) Two safety shutoff valves in series with a combined flame failure response and valve closing time not to exceed 5 seconds with strainer directly before the valves.

  (d) Programmed electronic flame safeguard including proven low-fire start, manual reset lockout, 100 percent shutoff (both pilot and main burner), and a separately supervised and proven pilot.

  Flame-sensing systems utilizing a UV scanner shall prove pilot and interrupt ignition spark prior to main burner valves being energized.

  (e) Two controls, one operating and one high limit, activated by temperature or pressure.

  (f) Burners relying on mechanical means to provide air for combustion shall have actual proof-of-air interlock device.

  (g) Power burners shall include proven prepurge of not less than 60 seconds at high-fire damper settings. This prepurge shall occur before every burner cycle, regardless of reason.

  (h) Installations with dampered combustion air openings shall prove damper open position before trial for burner ignition.

  (i) Vent dampers and flue dampers shall be interlocked to prevent burner ignition unless safely open.

  (j) One high oil or liquid fuel-pressure interlock, reset from flame safeguard or manually.

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  APPENDIX C

  (k) Where hot water or steam, two low water cutoffs.

  (l) An atomizing medium proving switch.

  (m) A low oil temperature switch for oil or liquid fuel requiring preheating.

  (n) A high oil temperature interlock for oil or liquid fuel requiring preheating.

  (o) The burner oil pump shall automatically not operate or rotate while the alternate fuel is firing.

  (p) A pressure-relief valve shall be provided between safety shutoff valves and between pump and safety valves where an integral valve is used with a pump.

  (q) A separate relief device is required on each transfer

  pump.

  (r) One low oil or liquid fuel-pressure interlock, reset from flame safeguard or manually.

  (s) Burners with automatic controls, prepurge, proofof-closure, modulation, or postpurge shall not use relays external to the flame safeguard to accomplish these functions.

  (4) Two million five hundred thousand to 12 499 999 Btu/h (733 kW to 3663.3 kW) per burner.

  (a) One approved manual shutoff valve lever handle.

  (b) One approved fuel-oil filter, installed on the supply piping.

  (c) Two safety shutoff valves in series, with a combined flame failure response and valve closing time not to exceed 5 seconds with strainer directly before the valves.

• CPC § 904.2.1 Medium relevance — show source text

  obtained from the outdoors. The closet shall be for the exclusive use of the central heating furnace or low-pressure boiler.

  (2) Central heating furnaces and low-pressure boilers shall be of the direct vent type.

  904.2.1 Self-Closing Doors. Self-closing doors shall swing easily and freely, and shall be equipped with a self-closing device to cause the door to close and latch each time it is opened. The closing mechanism shall not have a hold-open feature.

  904.2.2 Gasketing. Gasketing on gasketed doors or frames shall be furnished in accordance with the published listings of the door, frame, or gasketing material manufacturer.

  Exception: Where acceptable to the Authority Having Jurisdiction, gasketing of noncombustible or limitedcombustible material shall be permitted to be applied to the frame, provided closing and latching of the door are not inhibited.

  904.3 Clearance. Central heating furnaces and low-pressure boilers shall be provided with clearances in accordance with Section 904.3.1 through Section 904.3.7.

  904.3.1 Listed Units. Listed central heating furnaces and low-pressure boilers shall be installed with clearances in accordance with the terms of their listings and the manufacturer’s installation instructions. {NFPA 54:10.3.3.1}

  904.3.2 Unlisted Units. Unlisted central heating furnaces and low-pressure boilers shall be installed with clearances from combustible material not less than those specified in Table 904.3.2. [NFPA 54:10.3.3.2]

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  INSTALLATION OF SPECIFIC APPLIANCES

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  904.5 Temperature or Pressure Limiting Devices. Steam and hot water boilers, respectively, shall be provided with approved automatic limiting devices for shutting down the burner(s) to prevent boiler steam pressure or boiler water temperature from exceeding the maximum allowable working pressure or temperature. Safety limit controls shall not be used as operating controls. [NFPA 54:10.3.5]

  904.6 Low-Water Cutoff. All water boilers and steam boilers shall be provided with an automatic means to shut off the fuel supply to the burner(s) if the boiler water level drops below the lowest safe water line. In lieu of the low-water cutoff, water tube or coil-type boilers that require forced circulation to prevent overheating and failure shall have an approved flow sensing device arranged to shut down the boiler when the flow rate is inadequate to protect the boiler against overheating. [NFPA 54:10.3.6]

  904.7 Steam Safety and Pressure Relief Valves. Steam and hot water boilers shall be equipped, respectively, with listed or approved steam safety or pressure relief valves of appropriate discharge capacity and conforming with ASME requirements. A shutoff valve shall not be placed between the relief valve and the boiler or on discharge pipes between such valves and the atmosphere. [NFPA 54:10.3.7]

  904.7.1 Discharge. Relief valves shall be piped to discharge near the floor. [NFPA 54:10.3.7.1]

• CPC § 1308.2 Medium relevance — show source text

  1308.2 Pressure Relief Valves. All pressure relief valves shall meet the following requirements:

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  HEALTH CARE FACILITIES AND MEDICAL GAS AND MEDICAL VACUUM SYSTEMS

  (1) They shall be of brass, bronze, or stainless steel construction.

  (2) They shall be designed for the specific gas service.

  (3) They shall have a relief pressure setting not higher than the maximum allowable working pressure (MAWP) of the component with the lowest working pressure rating in the portion of the system being protected.

  (4) They shall be vented to the outside of the building, except that relief valves for compressed air systems having less than 3000 cubic feet (84 950 L) at STP shall be permitted to be diffused locally by means that will not restrict the flow.

  (5) They shall have a vent discharge line that is not smaller than the size of the relief valve outlet or ¾ NPS (20 mm), whichever is larger.

  (6) Where two or more relief valves discharge into a common vent line, the internal cross-sectional area of the common line shall be not less than the aggregate cross-sectional area of all relief valve vent discharge lines served.

  (7) They shall not discharge into locations creating potential hazards.

  (8) They shall have the discharge terminal turned down and screened to prevent the entry of rain, snow, or vermin.

  (9) They shall be designed in accordance with ASME B31.3.

  [NFPA 99:5.1.3.5.6.1]

  1308.3 Pressure-Relief Valve Requirements. Central supply systems for positive pressure gases shall include one or more relief valves, all meeting the following requirements:

  (1) They shall be located between each final line regulator and the source valve.

  (2) They shall have a relief setting that is 50 percent above the normal system operating pressure, as indicated in Table 1305.1. [NFPA 99:5.1.3.5.6.4]

  1309.0 Oxygen Concentrator Supply Units. 1309.1 Oxygen Requirements. Oxygen concentrator supply units for use with medical gas pipelines shall produce oxygen meeting the requirements of Oxygen 93 USP or Oxygen USP. [NFPA 99:5.1.3.9.1.1] 1309.2 Particulate Size. Output shall have less than or equal to 1.686 x 10 [-6] pounds per cubic yard (1 mg/m [3] ) of permanent particulates sized 1 micron or larger at normal atmospheric pressure. [NFPA 99:5.1.3.9.1.2] 1309.3 Suitability. Materials of construction on the air side of the oxygen concentrator unit shall be suitable for the service as determined by the manufacturer. [NFPA 99:5.1.3.9.1.3] 1309.4 Compatible Materials. Materials of construction on the oxygen side of the oxygen concentrator unit shall comply with Section 1307.4. [NFPA 99:5.1.3.9.1.4] 1309.5 Oxygen Concentrator Components. The components that make up the oxygen concentrator unit shall be as follows:

• CPC § 607.2 Medium relevance — show source text

  607.2 Private Well Water Tanks . . . . . . .154

  607.3 Potable Water Tanks . . . . . . . . . .154

  607.4 Venting . . . . . . . . . . . . . . . . . . . . .154

  607.5 Overflow . . . . . . . . . . . . . . . . . . . .154

  607.6 Valves . . . . . . . . . . . . . . . . . . . . . .154

  608.0 Water Pressure, Pressure Regulators, Pressure Relief Valves, and Vacuum Relief

  Valves . . . . . . . . . . . . . . . . . . . . . .154

  608.1 Inadequate Water Pressure . . . . .154

  608.2 Excessive Water Pressure . . . . . .154

  608.3 Expansion Tanks, and Combination Temperature and Pressure-Relief Valves . . . . .154

  608.4 Pressure Relief Valves . . . . . . . . .154

  608.5 Discharge Piping . . . . . . . . . . . . .154

  608.6 Water-Heating Devices . . . . . . . . .155

  608.7 Vacuum Relief Valves . . . . . . . . .155

  609.0 Installation, Testing, Unions, and Location . . . . . . . . . . . . . . . . .155

  609.1 Installation . . . . . . . . . . . . . . . . . .155

  609.2 Trenches . . . . . . . . . . . . . . . . . . . .155

  609.3 Under Concrete Slab . . . . . . . . . .155

  609.4 Testing . . . . . . . . . . . . . . . . . . . . .155

  609.5 Unions . . . . . . . . . . . . . . . . . . . . .155

  609.6 Location . . . . . . . . . . . . . . . . . . . .155

  609.7 Abutting Lot . . . . . . . . . . . . . . . . .155

  609.8 Pumps . . . . . . . . . . . . . . . . . . . . .155

  609.9 Low-Pressure Cutoff Required on Booster Pumps for Water Distribution Systems . . . . . . . . . . .156

  2025 CALIFORNIA PLUMBING CODE xxxiii

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  TABLE OF CONTENTS

  609.10 Disinfection of Potable Water System . . . . . . . . . . . . . . . . . . . . .156

  609.11 Water Hammer . . . . . . . . . . . . . . .156

  609.12 Pipe Insulation . . . . . . . . . . . . . . .156

  610.0 Size of Potable Water Piping . . . .156

  610.1 Size . . . . . . . . . . . . . . . . . . . . . . . .156

  610.2 Pressure Loss . . . . . . . . . . . . . . . .156

  610.3 Quantity of Water . . . . . . . . . . . . .157

• CPC § 608.3 Medium relevance — show source text

  The expansion tank shall be properly sized, securely fastened to the structure, and installed in accordance with the manufacturer’s installation instructions and listing. Systems designed by a licensed plumbing contractor or registered design professionals shall be permitted to use approved pressure relief valves in lieu of expansion tanks provided such relief valves have a maximum pressure relief setting of 100 psi (689 kPa) or less. 608.3 Expansion Tanks, and Combination Tempera- ture and Pressure-Relief Valves. A water system provided with a check valve, backflow preventer, or other normally closed device that prevents dissipation of building pressure back into the water main, independent of the type of water heater used, shall be provided with an approved, listed, and adequately sized expansion tank or other approved device having a similar function to control thermal expansion. Prepressurized water expansion tanks shall comply with IAPMO/ANSI Z1088. Such expansion tank or other approved device shall be installed on the building side of the check valve, backflow preventer, or other device and shall be sized, securely fastened to the structure, and installed in accordance with the manufacturer’s installation instructions.

  A water system containing storage water heating equipment shall be provided with an approved, listed, adequately sized combination temperature and pressure-relief valve, except for listed nonstorage instantaneous heaters having an inside diameter of not more than 3 inches (80 mm). Each such approved combination temperature and pressure-relief valve shall be installed on the water-heating device in an approved location based on its listing requirements and the manufacturer’s installation instructions. Each such combination temperature and pressure-relief valve shall be provided with a drain in accordance with Section 608.5.

  Exception: An expansion tank shall not be required for an instantaneous non-storage water heater. 608.4 Pressure Relief Valves. Each pressure relief valve shall be an approved automatic type with drain, and each such relief valve shall be set at a pressure of not more than 150 psi (1034 kPa). No shutoff valve shall be installed between the relief valve and the system. 608.5 Discharge Piping. The discharge piping serving a temperature relief valve, pressure relief valve, or combination of both shall have no valves, obstructions, or means of isolation and be provided with the following:

  (1) Not less than the size of the valve outlet and shall discharge full size to the flood level of the area receiving the discharge and pointing down.

  (2) Materials shall be rated at not less than the operating temperature of the system and approved for such use or shall comply with ASME A112.4.1.

  (3) Discharge pipe shall discharge independently by gravity through an air gap into the drainage system or outside of the building with the end of the pipe not exceeding 2 feet

  154 2025 CALIFORNIA PLUMBING CODE

  ), Copyright © 2025 IAPMO, and may not be used for any other purpose or distributed to any other persons or parties.

  WATER SUPPLY AND DISTRIBUTION

  (610 mm) and not less than 6 inches (152 mm) above the ground and pointing downwards.

  (4) Discharge in such a manner that does not cause personal injury or structural damage. (5) No part of such discharge pipe shall be trapped or subject to freezing. (6) The terminal end of the pipe shall not be threaded. (7) Discharge from a relief valve into a water heater pan shall be prohibited. (8) The discharge termination point shall be readily observable.