Safety Standards for Agriculture


Hazardous Materials-Liquefied Petroleum Gas
Chapter 296-307 - Part U-2

WAC

296-307-410 Storage and handling of liquefied petroleum gases.
296-307-41001
What does this part cover?
296-307-41003
Which LP-gas installations are not covered by this part?
296-307-41005
What definitions apply to this part?
296-307-41007
When must LP-gas be odorized?
296-307-41009
Must LP-gas containers and equipment be approved?
296-307-41011
What construction and test requirements must containers meet?
296-307-41013
How must containers be welded?
296-307-41015
How must containers be marked?
296-307-41017
Where must containers be located?
296-307-41019
What requirements apply to valves and accessories?
296-307-41021
What requirements apply to piping, tubing, and fittings?
296-307-41023
What specifications must hoses meet?
296-307-41025
What requirements apply to safety devices?
296-307-41027
How must indirect fired vaporizers be constructed and installed?
296-307-41029
How must atmospheric vaporizers be constructed and installed?
296-307-41031
How must direct gas-fired vaporizers be constructed and installed?
296-307-41033
How must direct gas-fired tank heaters be constructed and installed?
296-307-41035 How must dehydrators be constructed and installed?
296-307-41037
What are the maximum filling densities?
296-307-41039
What requirements apply to LP-gas in buildings?
296-307-41041
What requirements apply to transfer of liquids?
296-307-41043
Must workers be trained?
296-307-41045
What fire protection must be provided for LP-gas installations?
296-307-41047
What electrical requirements apply to LP-gas installations?
296-307-41049
What requirements apply to liquid-level gauging devices?
296-307-41051
What requirements apply to appliances?
296-307-415
Cylinder systems.
296-307-41501
What does this section cover?
296-307-41503
What is a “cylinder system?”
296-307-41505
How must containers be marked for cylinder systems?
296-307-41507
What additional requirements apply to cylinder systems installed outdoors?
296-307-41509
What additional requirements apply to cylinder systems installed indoors?
296-307-41511
What requirements apply to valves and accessories?
296-307-41513
What requirements apply to safety devices for cylinder systems?
296-307-41515
What other requirements apply to cylinder systems?
296-307-420
Systems using non-DOT containers.
296-307-42001
What does this section cover?
296-307-42003
How must non-DOT containers be designed and classified?
296-307-42005
What requirements apply to valves and accessories, filler pipes, and discharge pipes for non-DOT containers.
296-307-42007
What additional requirements apply to safety devices for non-DOT containers?
296-307-42009
When may non-DOT containers be reinstalled?
296-307-42011
What is the maximum capacity allowed for non-DOT containers?
296-307-42013
How must non-DOT containers be installed?
296-307-42015
How must non-DOT containers be protected?
296-307-42017
What requirements apply to non-DOT containers in industrial plants?
296-307-42019
What requirements apply to container-charging plants?
296-307-42021
What fire protection must be provided for non-DOT containers?
296-307-42023
What other requirements apply to non-DOT containers?
296-307-425
LP-gas as a motor fuel.
296-307-42501
What does this section cover?
296-307-42503
What general requirements apply to LP-gas used as a motor fuel?
296-307-42505
How must fuel containers be designed and classified?
296-307-42507
How must fuel containers be installed?
296-307-42509
What requirements apply to valves and accessories?
296-307-42511
What requirements apply to piping, tubing, and fittings?
296-307-42513
What requirements apply to safety devices?
296-307-42515
What requirements apply to vaporizers?
296-307-42517
What requirements apply to gas regulating and mixing equipment?
296-307-42519
What is the maximum container capacity allowed?
296-307-42521
What requirements apply to stationary engines used indoors?
296-307-42523
What requirements apply to portable engines used indoors?
296-307-42525
What requirements apply to industrial trucks used indoors?
296-307-42527
How must LP-gas-fueled vehicles be garaged?
296-307-430
Storage of containers awaiting use or resale.
296-307-43001
What does this section cover?
296-307-43003
What general requirements apply to storage of containers?
296-307-43005
How must containers be stored within buildings frequented by the public?
296-307-43007
How must containers be stored in buildings not frequented by the public?
296-307-43009
How must containers be stored within special buildings or rooms?
296-307-43011
How must containers be stored outdoors?
296-307-43013
What fire protection must be provided for stored containers?
296-307-435
LP-gas system installations on commercial vehicles.
296-307-43501
What does this section cover?
296-307-43503
How must containers be constructed?
296-307-43505
What is the maximum capacity allowed for LP-gas installations on commercial vehicles?
296-307-43507
Where must systems be located?
296-307-43509
What requirements apply to valves and accessories?
296-307-43511
What requirements apply to to safety devices?
296-307-43513
What types of systems may be used on commercial vehicles?
296-307-43515
What requirements apply to enclosures and mountings?
296-307-43517
What requirements apply to piping, tubing, and fittings?
296-307-43519
What requirements apply to appliances?
296-307-43521
What general precautions must be followed for LP-gas system installations on commercial vehicles?
296-307-43523
How must containers be charged?
296-307-43525
What fire protection must be provided for mobile cook units?
296-307-440
LP-gas service stations?
296-307-44001
What does this section cover?
296-307-44003
How must storage containers be designed and classified?
296-307-44005
What requirements apply to valves and accessories?
296-307-44007
What requirements apply to safety devices?
296-307-44009
What is the maximum capacity allowed for containers?
296-307-44011
How must storage containers be installed?
296-307-44013
What equipment must be protected against tampering?
296-307-44015
What requirements apply to the transport truck unloading point?
296-307-44017
What requirements apply to piping, valves, and fittings?
296-307-44019
What requirements apply to pumps and accessory equipment?
296-307-44021
What requirements apply to LP-gas dispensing devices?
296-307-44023
Is smoking allowed at LP-gas service stations?
296-307-44025
What fire protection must be provided at LP-gas service stations?

WAC 296-307-410 Storage and handling of liquefied petroleum gases.

[Recodified as 296-307-410. 97-09-013, filed 4/7/97, effective 4/7/97. Statutory Authority: RCW 49.17.040, [49.17.]050 and [49.17.]060. 96-22-048, 296-306A-410, filed 10/31/96, effective 12/1/96.]

WAC 296-307-41001 What does this part cover? 

Chapter 296-307 WAC Part U2 covers the storage and handling of liquefied petroleum gases.

The requirements of WAC 296-307-410 apply to all LP-gas installations covered by this part.

For additional requirements related to:

See WAC:

Cylinder systems

296-307-415

Systems using non-DOT containers

296-307-420

LP-gas as a motor fuel

296-307-425

Storage of containers awaiting use or resale

296-307-430

LP-gas installations on commercial vehicles

296-307-435

LP-gas service stations

296-307-440

[Statutory Authority: Chapter 49.17.040 RCW. 98-24-096 (Order 98-13) 296-307-41001, filed 12/01/98, effective 03/01/99. [Recodified as 296-307-41001. 97-09-013, filed 4/7/97, effective 4/7/97. Statutory Authority: RCW 49.17.040, [49.17.]050 and [49.17.]060. 96-22-048, 296-306A-41001, filed 10/31/96, effective 12/1/96.]

 

WAC 296-307-41003 Which LP-gas installations are not covered by this part?

(1) This part does not apply to:

(a) LP-gas refrigerated storage systems;

(b) LP-gas used with oxygen;

(c) LP-gas used in utility gas plants (covered by the National Fire Protection Association Standard for the Storage and Handling of Liquefied Petroleum Gases at Utility Gas Plants, NFPA No. 59-1968);

(d) Low-pressure (less than 1/2 pound per square inch or 14 inches water column) LP-gas piping systems, and the installation and operation of residential and commercial appliances supplied through such systems. The National Fire Protection Association Standard for the Installation of Gas Appliances and Gas Piping, NFPA 54-1969 apply to these systems.

(2) LP-gas installations, equipment, and appliances that met the requirements of the National Fire Protection Association Standard for the Storage and Handling of Liquefied Petroleum Gases NFPA No. 58-1972, 1973 at the time of manufacture or installation may be used if they do not create a hazard to employees.

[Recodified as 296-307-41003. 97-09-013, filed 4/7/97, effective 4/7/97. Statutory Authority: RCW 49.17.040, [49.17.]050 and [49.17.]060. 96-22-048, 296-306A-41003, filed 10/31/96, effective 12/1/96.]

WAC 296-307-41005 What definitions apply to this part?

Adequate ventilation,” for fire prevention during normal operation, means the concentration of the gas in a gas-air mixture does not exceed 25% of the lower flammable limit.

Containers” means all vessels, such as tanks, cylinders, or drums, used to transport or store LP-gases.

DOT” means the federal Department of Transportation.

DOT container” means a container that meets DOT regulations.

DOT cylinder” means a cylinder that meets DOT regulations.

DOT regulations/requirements/specifications” means the DOT regulations of 49 CFR part 178.

Liquefied petroleum gases” and “LP-gas” means any material that is composed mostly of any of the following: Hydrocarbons, or mixtures of them; propane; propylene; butanes (normal butane or iso-butane); and butylenes.

PSIA” pounds per square inch absolute.

PSIG” means pounds per square inch gauge.

Systems” means an assembly of the container or containers, major devices such as vaporizers, safety-relief valves, excess flow valves, regulators, and piping connecting such parts.

Vaporizer-burner” means an integral vaporizer-burner unit, dependent upon the heat generated by the burner to vaporize the liquid used for dehydrators or dryers.

[Recodified as 296-307-41005. 97-09-013, filed 4/7/97, effective 4/7/97. Statutory Authority: RCW 49.17.040, [49.17.]050 and [49.17.]060. 96-22-048, 296-306A-41005, filed 10/31/96, effective 12/1/96.]

WAC 296-307-41007 When must LP-gas be odorized? 

You must ensure that all LP-gas is odorized by an approved agent to indicate by distinct odor, the presence of gas down to concentration in air of a maximum of 1/5 the lower limit of flammability.

Exception: Odorization is not required if it will create a hazard in further processing, or if it serves no useful purpose as a warning agent.

Note: The odorization requirement may be met by using 1.0 pounds of ethyl mercaptan, 1.0 pounds of thiophene, or 1.4 pounds of amyl mercaptan per ten thousand gallons of LP-gas. You may use any odorant and quantity that meets the requirements of this section.

[Recodified as 296-307-41007. 97-09-013, filed 4/7/97, effective 4/7/97. Statutory Authority: RCW 49.17.040, [49.17.]050 and [49.17.]060. 96-22-048, 296-306A-41007, filed 10/31/96, effective 12/1/96.]

WAC 296-307-41009 Must LP-gas containers and equipment be approved?

(1) Each system of DOT containers must have approved container valves, connectors, manifold valve assemblies, and regulators.

(2) Each non-DOT system using containers of 2,000 gallons or less water capacity, must have a container assembly, one or more regulators, and other necessary parts. The entire system, or the container assembly with the regulators, must be individually listed by a nationally recognized testing laboratory.

Container assembly” means the container and fittings for all openings, including shut-off vales, excess flow valves, liquid-level gauging devices, safety-relief devices, and protective housing.

(3) In systems using containers of over 2,000 gallons water capacity, each regulator, container, valve, excess flow valve, gauging device, and relief valve, must be listed by a nationally recognized testing laboratory.

(4) All DOT containers must be constructed, tested, and stamped according to the DOT specifications effective at the date of their manufacture.

[Recodified as 296-307-41009. 97-09-013, filed 4/7/97, effective 4/7/97. Statutory Authority: RCW 49.17.040, [49.17.]050 and [49.17.]060. 96-22-048, 296-306A-41009, filed 10/31/96, effective 12/1/96.]

 

WAC 296-307-41011 What construction and test requirements must containers meet?

(1) Containers must be designed, constructed, and tested according to the Rules for Construction of Unfired Pressure Vessels, section VIII, Division 1, American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code, 1968 edition, unless otherwise specified.

(2) Containers constructed according to the 1949 and earlier editions of the ASME Code are exempt from U-2 through U-10 and U-19 of the code. Containers constructed according to U-70 in the 1949 and earlier editions do not meet the requirements of this section.

(3) Containers designed, constructed, and tested prior to July 1, 1961, according to the Code for Unfired Pressure Vessels for Petroleum Liquids and Gases, 1951 edition with 1954 Addenda, of the American Petroleum Institute and the American Society of Mechanical Engineers are considered in compliance. Containers constructed according to API-ASME Code do not have to comply with section I or with the appendix to section I. W-601 through W-606 in the 1943 and earlier editions do not apply.

[Recodified as 296-307-41011. 97-09-013, filed 4/7/97, effective 4/7/97. Statutory Authority: RCW 49.17.040, [49.17.]050 and [49.17.]060. 96-22-048, 296-306A-41011, filed 10/31/96, effective 12/1/96.]

WAC 296-307-41013 How must containers be welded?

(1) You must ensure that all welding to the shell, head, or any other part of the container subject to internal pressure, meets the requirements of the code under which the tank was fabricated. You may weld on saddle plates, lugs, or brackets attached to the container by the tank manufacturer.

(2) When you must repair or modify DOT containers by welding, you must return the container to a qualified manufacturer, making containers of the same type, to make the repair or modification according to DOT regulations.

[Recodified as 296-307-41013. 97-09-013, filed 4/7/97, effective 4/7/97. Statutory Authority: RCW 49.17.040, [49.17.]050 and [49.17.]060. 96-22-048, 296-306A-41013, filed 10/31/96, effective 12/1/96.]

WAC 296-307-41015 How must containers be marked?

(1) You must ensure that containers are marked according to DOT regulations or with the following:

(a) Indication that the container meets the requirements of the code under which it is constructed, and all marks required by that code.

(b) Indication whether the container is designed for underground or aboveground installation or both. If intended for both and different style hoods are provided, the marking must indicate the proper hood for each type of installation.

(c) The name and address of the supplier of the container, or with the trade name of the container.

(d) The water capacity of the container in pounds or gallons, United States standard.

(e) The pressure in psig, for which the container is designed.

(f) The wording “This container must not contain a product with a vapor pressure greater than psig at 100F.”

(g) The tare weight, for containers with a water capacity of three hundred pounds or less.

(h) Indication of the maximum fill level for liquid at temperatures between 20F and 130F. Markings must be in maximum increments of 20F. This marking may be located on the liquid level gauging device.

Exception: Containers provided with fixed maximum level indicators or that are filled by weighing are exempt from this requirement.

(i) The outside surface area in square feet.

(2) The markings must be on a metal nameplate attached to the container so that it is visible after the container is installed.

(3) When LP-gas and one or more other gases are stored or used in the same area, the containers must be marked to identify their content. Marking must be according to American National Standard Z48.1-1954, “Method of Marking Portable Compressed Gas Containers to Identify the Material Contained.”

[Recodified as 296-307-41015. 97-09-013, filed 4/7/97, effective 4/7/97. Statutory Authority: RCW 49.17.040, [49.17.]050 and [49.17.]060. 96-22-048, 296-306A-41015, filed 10/31/96, effective 12/1/96.]

WAC 296-307-41017 Where must containers be located? You must ensure that containers are located according to the following:

(1) Containers and first stage regulating equipment are located outdoors.

Containers may be located indoors under any of the following conditions:

(a) In buildings used exclusively for container charging, vaporization pressure reduction, gas mixing, gas manufacturing, or distribution;

(b) When portable use is necessary and meets the requirements of WAC 296-307-41509;

(c) LP-gas fueled stationary or portable engines that meet the requirements of WAC 296-307-42521 or 296-307-42523;

(d) LP-gas fueled industrial trucks that meet the requirements of WAC 296-307-42525;

(e) LP-gas fueled vehicles garaged according to WAC 296-307-42527; or

(f) Containers awaiting use or resale when stored according to WAC 296-307-430.

(2) Each individual container is located away from the nearest important building, group of buildings, or line of adjoining property that may be built on, according to Table U-1.

TABLE U-1 Minimum Distances

Water capacity per container

Containers Underground Aboveground

Between above-ground containers

Less than 125 galsa

10 feet

None

None

125-250 gals

10 feet

10 feet

None

251-500 gals

10 feet

10 feet

3 feet

501-2,000 gals

25 feetb

25 feetb

3 feet

2,001-30,000 gals

50 feet

50 feet

5 feet

30,001-70,000 gals

50 feet

75 feet

1/4 sum of diameters of adjacent containers

70,001-90,000 gals

50 feet

100 feet

1/4 sum of diameters of adjacent containers

(a) If the total water capacity of a multicontainer installation at a consumer site is 501 gallons or more, the minimum distance must comply with this table, applying the aggregate capacity instead of the capacity per container. For multiple installations, installations must be at least twenty-five feet apart. Do not apply the minimum distances between aboveground containers to such installations.

(b) Distance requirements may be reduced to 10 feet for a single container of 1200 gallons water capacity or less, if the container is at least 25 feet from any other LP-gas container of more than 125 gallons water capacity.

(c) In buildings devoted exclusively to gas manufacturing and distributing operations, the distances may be reduced if no containers of more than 500 gallons water capacity are located closer than ten feet to gas manufacturing and distributing buildings.

(3) Containers installed for use must not be stacked one above the other.

(4) In industrial installations involving containers of 180,000 gallons total water capacity or more, where serious exposures from the container to adjacent properties are common, firewalls or other means of protection designed and constructed according to good engineering practices are required.

(5) Readily ignitible material such as weeds and long dry grass is removed within ten feet of any container.

(6) The minimum separation between LP-gas containers and flammable liquid tanks is twenty feet; the minimum separation between a container and the centerline of the dike is ten feet.

Exception: This does not apply when LP-gas containers of 125 gallons or less capacity are installed adjacent to Class III flammable liquid tanks of 275 gallons or less capacity.

(7) The accumulation of flammable liquids under adjacent LP-gas containers is prevented by a means such as diking, diversion curbs, or grading.

(8) When dikes are used with flammable liquid tanks, no LP-gas containers are located within the diked area.

[Statutory Authority: Chapter 49.17.040 RCW. 98-24-096 (Order 98-13) 296-307-41017, filed 12/01/98, effective 03/01/99. [Recodified as 296-307-41017. 97-09-013, filed 4/7/97, effective 4/7/97. Statutory Authority: RCW 49.17.040, [49.17.]050 and [49.17.]060. 96-22-048, 296-306A-41017, filed 10/31/96, effective 12/1/96.]

 

WAC 296-307-41019 What requirements apply to valves and accessories?

(1) Valves, fittings, and accessories connected directly to the container including primary shut-off valves, must have a rated working pressure of at least 250 psig and must be of material and design suitable for LP-gas service. The use of cast iron for container valves, fittings, and accessories is prohibited. Container valves may be made of malleable or nodular iron.

(2) Connections to containers must have shut-off valves located as close to the container as practical.

Exception: This does not apply to safety-relief connections, liquid level gauging devices, and plugged openings.

(3) All required excess flow valves must close automatically at the rated flows of vapor or liquid specified by the manufacturer. The connections, lines, valves, and fittings must have a greater capacity than the rated flow of the excess flow valve.

(4) Liquid level gauging devices that are constructed so that outward flow is a maximum of that passed by a No. 54 drill size opening may be installed without excess flow valves.

(5) Openings from container or through fittings attached directly on container to which pressure gauge connection is made, need not have shut-off or excess flow valves if such openings are restricted to not larger than No. 54 drill size opening.

(6) Required excess flow and back pressure check valves must be located inside the container or outside where the line enters the container. When located outside, the installation must be made to prevent any stress beyond the excess flow or back pressure check valve from causing a break between the container and the valve.

Exception: This does not apply to systems using containers with a water capacity greater than 2-1/2 pounds (nominal one pound LP-gas capacity).

(7) Excess flow valves must be designed with a bypass that is a maximum of No. 60 drill size opening to allow equalization of pressures.

(8) Containers of more than 30 gallons water capacity and less than 2,000 gallons water capacity, filled on a volumetric basis, and manufactured after December 1, 1963, must be equipped for filling into the vapor space.

[Recodified as 296-307-41019. 97-09-013, filed 4/7/97, effective 4/7/97. Statutory Authority: RCW 49.17.040, [49.17.]050 and [49.17.]060. 96-22-048, 296-306A-41019, filed 10/31/96, effective 12/1/96.]

WAC 296-307-41021 What requirements apply to piping, tubing, and fittings?

(1) Pipe must be wrought iron or steel (black or galvanized), brass, copper, or aluminum alloy. Aluminum alloy pipe must be at least Schedule 40 according to the specifications for Aluminum Alloy Pipe, ANSI H38.7-1969 (ASTM, B241-1969), and must be suitably marked at each end of each length indicating compliance with ANSI specifications. Alloy 5456 is prohibited.

Exception: This does not apply to piping for LP-gas used as a motor fuel or to piping on commercial vehicles.

(2) Aluminum alloy pipe must be protected against external corrosion whenever:

(a) It is in contact with dissimilar metals other than galvanized steel; or

(b) Its location is subject to repeated wetting by such liquids as water (except rain water), detergents, sewage, or leaking from other piping; or

(c) It passes through flooring, plaster, masonry, or insulation.

Galvanized sheet steel or pipe, galvanized inside and out, are considered suitable protection.

(3) Aluminum pipe must be three-fourths inch nominal and shall not be used for pressures exceeding 20 psig. Aluminum alloy pipe must not be installed within six inches of the ground.

(a) Vapor piping with operating pressures not exceeding 125 psig must be suitable for a working pressure of at least 125 psig. Pipe must be at least Schedule 40 ASTM A-53-69, Grade B Electric Resistance Welded and Electric Flash Welded Pipe or equal.

(b) Vapor piping with operating pressures over 125 psig and all liquid piping must be suitable for a working pressure of at least 250 psig. Pipe must be at least Schedule 80 if joints are threaded or threaded and back welded. At least Schedule 40 (ASTM A-53-1969 Grade B Electric Resistance Welded and Electric Flash Welded Pipe or equal) must be used if joints are welded, or welded and flanged.

(4) Tubing must be seamless copper, brass, steel, or aluminum alloy. Copper tubing must be of Type K or L or equivalent as covered in the Specification for Seamless Copper Water Tube, ANSI H23.1-1970 (ASTM B88-1969). Aluminum alloy tubing must be of Type A or B or equivalent as covered in Specification ASTM B210-1968 and must be suitably marked every 18 inches indicating compliance with ASTM specifications. The minimum nominal wall thickness of copper tubing and aluminum alloy tubing must be as specified in Table U-2 and Table U-3.

TABLE U-2 Wall Thickness of Copper Tubing1 

Note: The standard tube size is one-eighth inch smaller than its nominal outside diameter.

Standard size (inches)

Nominal O.D. (inches)

Nominal wall thickness (inches)

   

Type K

Type L

1/4

0.375

0.035

0.030

3/8

0.500

0.049

0.035

1/2

0.625

0.049

0.040

5/8

0.750

0.049

0.042

3/4

0.875

0.065

0.045

1

1.125

0.065

0.050

1 1/4

1.375

0.065

0.055

1 1/2

1.625

0.072

0.060

2

2.125

0.083

0.070

1Based on data in Specification for Seamless Copper Water Tubing, ANSI H23.1-1970 (ASTM B-88-69).

TABLE U-3 Wall Thickness of Aluminum Alloy Tubing1

Outside diameter (inches)

Nominal wall thickness (inches)

 

Type A

Type B

3/8

0.035

0.049

1/2

0.035

0.049

5/8

0.042

0.049

3/4

0.049

0.058

1Based on data in Standard Specification for Aluminum-Alloy Drawn Seamless Coiled Tubes for Special Purpose Applications, ASTM B210-68.

(5) Aluminum alloy tubing must be protected against external corrosion whenever:

(a) It is in contact with dissimilar metals other than galvanized steel; or

(b) Its location is subject to repeated wetting by liquids such as water (except rainwater), detergents, sewage, or leakage from other piping; or

(c) It passes through flooring, plaster, masonry, or insulation.

Galvanized sheet steel or pipe, galvanized inside and out, are considered suitable protection.

(6) The maximum outside diameter for aluminum alloy tubing must be three-fourths inch and must not be used for pressures exceeding 20 psig. Aluminum alloy tubing installed within six inches of the ground is prohibited.

(7) In systems where the gas in liquid form enters the building without pressure reduction, only heavy walled seamless brass or copper tubing with an internal diameter a maximum of 3/32 inch, and a wall thickness of at least 3/64 inch shall be used.

Exception: This requirement does not apply to research and experimental laboratories, buildings or separate fire divisions of buildings used exclusively for housing internal combustion engines, and to commercial gas plants or bulk stations where containers are charged, nor to industrial vaporizer buildings, nor to buildings, structures, or equipment under construction or undergoing major renovation.

(8) Pipe joints must be screwed, flanged, welded, soldered, or brazed with a material having a melting point over 1,000F. Joints on seamless copper, brass, steel, or aluminum alloy gas tubing shall be made by approved gas tubing fittings, or soldered or brazed with a material having a melting point over 1,000F.

(9) For operating pressures of 125 psig or less, fittings must be designed for a pressure of at least 125 psig. For operating pressures above 125 psig, fittings must be designed for a minimum of 250 psig.

(10) Threaded cast iron pipe fittings are prohibited. Aluminum alloy fittings must be used with aluminum alloy pipe and tubing. Insulated fittings must be used where aluminum alloy pipe or tubing connects with a dissimilar metal. You may use malleable, nodular, or higher strength gray iron for fittings.

Note: Strainers, regulators, meters, compressors, pumps, etc., are not to be considered as pipe fittings.

(11) All materials such as valve seats, packing, gaskets, diaphragms, etc., must be resistant to the action of LP-gas under the service conditions to which they are subjected.

(12) All piping, tubing, or hose must be tested after assembly and proved free from leaks at least normal operating pressures. After installation, piping and tubing of all domestic and commercial systems must be tested and proved free of leaks using a manometer or equivalent device that will indicate a drop in pressure. Test made by flame is prohibited.

(13) You must ensure that piping allows for expansion, contraction, jarring, and vibration, and settling. You may use flexible connections.

(14) Piping outside buildings may be buried, aboveground, or both, but must be well supported and protected against physical damage. Where soil conditions warrant, all piping must be protected against corrosion. Where condensation may occur, the piping must be pitched back to the container, or you must provide a means for revaporization of the condensate.

[Recodified as 296-307-41021. 97-09-013, filed 4/7/97, effective 4/7/97. Statutory Authority: RCW 49.17.040, [49.17.]050 and [49.17.]060. 96-22-048, 296-306A-41021, filed 10/31/96, effective 12/1/96.]

 

WAC 296-307-41023 What specifications must hoses meet?

(1) Hose shall be fabricated of materials that are resistant to the action of LP-gas in the liquid and vapor phases. If wire braid is used for reinforcing the hose, it must be of corrosion-resistant material such as stainless steel. 

(2) Hose subject to container pressure must be marked “LP-gas” or “LPG” at not greater than ten-foot intervals.

(3) Hose subject to container pressure must be designed for a bursting pressure of not less than 1,250 psig.

(4) Hose subject to container pressure must be listed by a nationally recognized testing laboratory.

(5) Hose connections subject to container pressure must be able to withstand, without leaking, a test pressure of not less than 500 psig.

(6) Hose and hose connections on the low-pressure side of the regulator or reducing valve must be designed for a bursting pressure of not less than 125 psig or five times the set pressure of the relief devices protecting that portion of the system, whichever is higher.

(7) Hose may be used on the low-pressure side of regulators to connect to other than domestic and commercial gas appliances under the following conditions:

(a) The appliances connected with hose are portable and need a flexible connection.

(b) For use inside buildings, the hose is of minimum practical length, but is a maximum of six feet. Hose must not extend from one room to another, nor pass through any walls, partitions, ceilings, or floors. Such hose must not be concealed from view or used in a concealed location.

Exception: For use outside of buildings, the hose may exceed this length but must be kept as short as practical.

(c) The hose must be approved and must not be used where it may be exposed to temperatures above 125F. The hose must be securely connected to the appliance. Rubber slip ends are prohibited.

(d) The shut-off valve for an appliance connected by hose must be in the metal pipe or tubing and not at the appliance end of the hose. When shut-off valves are installed close to each other, precautions must be taken to prevent operation of the wrong valve.

(e) Hose used for connecting to wall outlets must be protected from physical damage.

[Recodified as 296-307-41023. 97-09-013, filed 4/7/97, effective 4/7/97. Statutory Authority: RCW 49.17.040, [49.17.]050 and [49.17.]060. 96-22-048, 296-306A-41023, filed 10/31/96, effective 12/1/96.]

WAC 296-307-41025 What requirements apply to safety devices?

(1) Every container except those constructed according to DOT specifications and every vaporizer (except motor fuel vaporizers and vaporizers described in WAC 296-307-41029(3) and 296-307-42007 (6)(a) whether heated by artificial means or not, must have one or more safety-relief valves of spring-loaded or equivalent type. These valves must be arranged to afford free vent to the outer air with discharge not less than five feet horizontally away from any opening into the building that is below such discharge. The rate of discharge must be according to the requirements of subsection (2) or (4) of this section.

(2) Minimum required rate of discharge in cubic feet per minute of air at one hundred twenty percent of the maximum permitted start to discharge pressure for safety-relief valves to be used on containers other than those constructed according to DOT specification must be as follows:

Surface area Flow rate sq. ft. CFM air

Surface area Flow rate sq. ft. CFM air

Surface area Flow rate sq. ft. CFM air

20 or less

626

170

3,620

550

9,470

25

751

175

3,700

600

10,170

30

872

180

3,790

650

10,860

35

990

185

3,880

700

11,550

40

1,100

190

3,960

750

12,220

45

1,220

195

4,050

850

13,540

50

1,330

200

4,130

900

14,190

55

1,430

210

4,300

950

14,830

60

1,540

220

4,470

1,000

15,470

65

1,640

230

4,630

1,050

16,100

70

1,750

240

4,800

1,100

16,720

75

1,850

250

4,960

1,150

17,350

80

1,950

260

5,130

1,200

17,960

85

2,050

270

5,290

1,250

18,570

90

2,150

280

5,450

1,300

19,180

95

2,240

290

5,610

1,350

19,780

100

2,340

300

5,760

1,400

20,380

105

2,440

310

5,920

1,450

20,980

110

2,530

320

6,080

1,500

21,570

115

2,630

330

6,230

1,550

22,160

120

2,720

340

6,390

1,600

22,740

125

2,810

350

6,540

1,650

23,320

130

2,900

360

6,690

1,700

23,900

135

2,990

370

6,840

1,750

24,470

140

3,080

380

7,000

1,800

25,050

145

3,170

390

7,150

1,850

25,620

150

3,260

400

7,300

1,900

26,180

155

3,350

450

8,040

1,950

26,750

160

3,440

500

8,760

2,000

27,310

165

3,530

       

Surface area = total outside surface area of container in square feet.

(3) When the surface area is not stamped on the name plate or when the marking is not legible, calculate the area with one of the following formulas:

  • Hemispherical heads: Area = (overall length) X (outside diameter) X 3.1416.

  • Other than hemispherical heads: Area = (overall length) + 0.3 (outside diameter) X (outside diameter ) X 3.1416.

Note: This formula is not exact, but will give results within the limits of practical accuracy for the sole purpose of sizing relief valves.

  • Spherical container: Area = (outside diameter)2 X 3.1416.

  • Flow rate: CFM air = required flow capacity in cubic feet per minute of air at standard conditions, 60F and atmospheric pressure (14.7 psia).

For containers with total outside surface area greater than 2,000 sq. ft., the formula is: Flow rate CFM air = 53.632 A0.82 where A = outside surface area of the container in square feet.

Valves not marked “air” have flow rate marking in cubic feet per minute of LP-gas. These can be converted to ratings in cubic feet per minute of air by multiplying the LP-gas ratings by factors listed below. Air flow ratings can be converted to ratings in cubic feet per minute of LP-gas by dividing the air ratings by the factors listed below.

Air Conversion Factors

 

Container Type

100

125

150

175

200

Air Conversion Factor

1.162

1.142

1.113

1.078

1.010

(4) The minimum required rate of discharge for safety-relief valves for LP-gas vaporizers (steam heated, water heated, and direct fired) must be determined as follows:

(a) Obtain the total surface area by adding the surface area of vaporizer shell in square feet directly in contact with LP-gas and the heat exchanged surface area in square feet directly in contact with LP-gas.

(b) Obtain the minimum required rate of discharge in cubic feet of air per minute, at 60F and 14.7 psia from subsection (2) of this section, for this total surface area.

(5) Container and vaporizer safety-relief valves must be set to start to discharge, with relation to the design pressure of the container, according to the following:

Containers

Minimum (Percent)

Maximum (Percent)

ASME Code; Par. U-68, U-69-1949 and earlier editions.

110

*125

ASME Code; Par. U-200, U-201-1949 edition

88

*100

ASME Code-1950, 1952, 1956, 1959, 1962, 1965 and 1968 (Division 1) editions

88

*100

API-ASME Code-all editions

88

*100

DOT

As prescribed in 49 CFR Chapter I

*Manufacturers of safety-relief valves are allowed a plus tolerance not exceeding 10% of the set pressure marked on the valve.

(6) Safety-relief devices used with systems employing non-DOT containers must be constructed to discharge at not less than the rates shown in subsection (2) of this section, before the pressure is in excess of 120% of the maximum (not including the 10% referred to in subsection (5) of this section) permitted start-to-discharge pressure setting of the device.

(7) In high temperature areas, you must use a lower vapor pressure product or a higher designed pressure vessel to prevent the safety valves from opening. The tanks may be protected by cooling devices such as spraying, shading, or other means.

(8) Safety-relief valves must be arranged to minimize tampering. For external pressure setting or adjustment, the relief valves must have an approved sealable adjustment.

(9) Shut-off valves are prohibited between safety-relief devices and the container, equipment, or piping.

Exception: A shut-off valve may be used where the arrangement of the valve allows the required capacity flow through the safety-relief device.

(10) Safety-relief valves must have direct communication with the vapor space of the container.

(11) Each safety-relief valve must be plainly and permanently marked with the following:

(a) Container type of the pressure vessel on which the valve is designed to be installed;

(b) The pressure in psig at which the valve is set to discharge;

(c) The actual rate of discharge of the valve in cubic feet per minute of air at 60F and 14.7 psia; and

(d) The manufacturer's name and catalog number.

For example: T200-250-4050 AIR: Indicates that the valve is suitable for use on a Type 200 container, that it is set to start to discharge at 250 psig; and that its rate of discharge is 4,050 cubic feet per minute of air.

(12) Safety-relief valve assemblies and their connections must be large enough to provide the required rate of flow for the container on which they are installed.

(13) A hydrostatic relief valve must be installed between each pair of shut-off valves on LP-gas liquid piping. The start-to-discharge pressure setting of such relief valves must be a maximum of 500 psig. The minimum setting on relief valves installed in piping connected to non-DOT containers shall be 140% of the container relief valve setting. For piping connected to DOT containers, the minimum must be 400 psig. The relief valve should not be installed in the pump discharge piping if the same protection can be provided by installing the relief valve in the suction piping. The start-to-discharge pressure setting of such a relief valve, if installed on the discharge side of a pump, must exceed the maximum pressure permitted by the recirculation device in the system.

(14) The discharge from any safety-relief device must not terminate in or beneath any building.

Exception: This requirement does not apply to relief devices covered by WAC 296-307-41017(1), 296-307-41507(1) or 296-307-41509.

(15) Container safety-relief devices and regulator relief vents must be located at least five feet in any direction from air openings into sealed combustion system appliances or mechanical ventilation air intakes.

[Statutory Authority: Chapter 49.17.040 RCW. 98-24-096 (Order 98-13) 296-307-41025, filed 12/01/98, effective 03/01/99. [Recodified as 296-307-41025. 97-09-013, filed 4/7/97, effective 4/7/97. Statutory Authority: RCW 49.17.040, [49.17.]050 and [49.17.]060. 96-22-048, 296-306A-41025, filed 10/31/96, effective 12/1/96.]

 

WAC 296-307-41027 How must indirect fired vaporizers be constructed and installed? 

Indirect fired vaporizers utilizing steam, water, or other heating medium must be constructed and installed according to the following:

(1) Vaporizers must be constructed according to the requirements of WAC 296-307-41011 and must be permanently marked as follows:

(a) With the code marking signifying the specifications to which the vaporizer is constructed;

(b) With the allowable working pressure and temperature for which the vaporizer is designed;

(c) With the sum of the outside surface area and the inside heat exchange surface area expressed in square feet; and

(d) With the name or symbol of the manufacturer.

(2) Vaporizers with an inside diameter of six inches or less exempted by the ASME Unfired Pressure Vessel Code, Section VIII of the ASME Boiler and Pressure Vessel Code, 1968, must have a design pressure of at least 250 psig and need not be permanently marked.

(3) Heating or cooling coils installed inside a storage container are prohibited.

(4) Vaporizers may be installed in buildings, rooms, sheds, or lean-tos used exclusively for gas manufacturing or distribution, or in other light, noncombustible structures that are well ventilated near the floor line and roof.

Exception: When vaporizing and/or mixing equipment is in a structure not used exclusively for gas manufacturing or distribution, the structure or room must be separated from the remainder of the building. The separation must be a wall designed to withstand a static pressure of at least 100 pounds per square foot. This wall must have no openings or pipe or conduit passing through it. Such structure or room must have adequate ventilation and must have a roof or at least one exterior wall of lightweight construction.

(5) All DOT vaporizers must have, at or near the discharge, a safety-relief valve providing an effective rate of discharge according to WAC 296-307-41025.

(6) The heating medium lines into and out of the vaporizer must have a mechanism to prevent the flow of gas into the heat systems in the event of tube rupture in the vaporizer. Vaporizers must have an automatic means to prevent liquid from passing through the vaporizers to the gas discharge piping.

(7) The device that supplies heat to produce steam, hot water, or other heat may be installed in a building, compartment, room, or lean-to ventilated near the floorline and roof to the outside. The device must be separated from all compartments or rooms containing LP-gas vaporizers, pumps, and central gas mixing devices by a wall designed to withstand a static pressure of at least 100 pounds per square foot. This wall must have no openings or pipes or conduit passing through it.

Exception: This requirement does not apply to the domestic water heaters that may supply heat for a vaporizer in a domestic system.

(8) Gas-fired heating systems supplying heat exclusively for vaporization must have automatic safety devices to shut off the flow of gas to main burners, if the pilot light should fail.

(9) Vaporizers may be an integral part of a fuel storage container directly connected to the liquid section or gas section or both.

(10) Fusible plugs are prohibited on vaporizers.

(11) Vaporizer houses must not have unprotected drains to sewers or sump pits.

[Statutory Authority: Chapter 49.17.040 RCW. 98-24-096 (Order 98-13) 296-307-41027, filed 12/01/98, effective 03/01/99. [Recodified as 296-307-41027. 97-09-013, filed 4/7/97, effective 4/7/97. Statutory Authority: RCW 49.17.040, [49.17.]050 and [49.17.]060. 96-22-048, 296-306A-41027, filed 10/31/96, effective 12/1/96.]

WAC 296-307-41029 How must atmospheric vaporizers be constructed and installed? 

Atmospheric vaporizers using heat from the ground or surrounding air must be installed as follows:

(1) Buried underground; or

(2) Located inside the building near where the pipe enters the building, if the capacity of the unit does not exceed one quart;

(3) Vaporizers of less than one quart capacity heated by the ground or surrounding air, may be installed without safety-relief valves if tests show that the assembly is safe.

[Recodified as 296-307-41029. 97-09-013, filed 4/7/97, effective 4/7/97. Statutory Authority: RCW 49.17.040, [49.17.]050 and [49.17.]060. 96-22-048, 296-306A-41029, filed 10/31/96, effective 12/1/96.]

 

WAC 296-307-41031 How must direct gas-fired vaporizers be constructed and installed? 

Direct gas-fired vaporizers must be constructed, marked, and installed as follows:

(1) According to the requirements of the American Society of Mechanical Engineers Boiler and Pressure Vessel Code, 1968, that apply to the maximum working conditions for which the vaporizer is designed.

(2) With the name of the manufacturer; rated Btu input to the burner; the area of the heat exchange surface in square feet; the outside surface of the vaporizer in square feet; and the maximum vaporizing capacity in gallons per hour.

(3) Vaporizers may be connected to the liquid section or the gas section of the storage container, or both. The container must have a manually operated valve in each connection that completely shuts off when desired, all flow of gas or liquid from container to vaporizer.

(4) Vaporizers with a maximum capacity of 35 gallons per hour must be located at least 5 feet from container shut-off valves. Vaporizers more than 35 gallon capacity but a maximum of 100 gallons per hour must be located at least 10 feet from the container shut-off valves. Vaporizers having a capacity greater than 100 gallons per hour must be located at least 15 feet from container shut-off valves.

(5) Vaporizers may be installed in buildings, rooms, housings, sheds, or lean-tos used exclusively for vaporizing or mixing of LP-gas. Vaporizing housing structures must be noncombustible, and well ventilated near the floorline and the highest point of the roof. When vaporizer and/or mixing equipment is located in a structure or room attached to or within a building, such structure or room must be separated from the remainder of the building by a wall designed to withstand a static pressure of at least 100 pounds per square foot. This wall must have no openings or pipes or conduit passing through it. The structure or room must have adequate ventilation, and a roof or at least one exterior wall of lightweight construction.

(6) Vaporizers must have at or near the discharge, a safety-relief valve providing an effective rate of discharge according to WAC 296-307-41025. The relief valve must be located where it is not subjected to temperatures over 140F.

(7) Vaporizers must have suitable automatic means to prevent liquid passing from the vaporizer to the gas discharge piping of the vaporizer.

(8) Vaporizers must have means for manually turning off the gas to the main burner and pilot.

(9) Vaporizers must have automatic safety devices to shut off the flow of gas to main burners if the pilot light should fail. When the flow through the pilot exceeds 2,000 Btu per hour, the pilot also must have an automatic safety device to shut off the flow of gas to the pilot should the pilot flame be extinguished.

(10) Pressure regulating and pressure reducing equipment located within 10 feet of a direct fired vaporizer must be separated from the open flame by an airtight noncombustible partition.

(11) Except as provided in subsection (5) of this section, the following minimum distances must be maintained between direct fired vaporizers and the nearest important building, group of buildings, or line of adjoining property that may be built on:

(a) Ten feet for vaporizers with a vaporizing capacity of 15 gallons per hour or less;

(b) Twenty-five feet for vaporizers with a vaporizing capacity of 16-100 gallons per hour;

(c) Fifty feet for vaporizers with a vaporizing capacity over 100 gallons per hour.

(12) Direct fired vaporizers must not raise the product pressure above the design pressure of the vaporizer equipment or above the pressure shown in the second column of Table U-8.

(13) Fusible plugs are prohibited on vaporizers.

(14) Vaporizers must not have unprotected drains to sewers or sump pits.

[Statutory Authority: Chapter 49.17.040 RCW. 98-24-096 (Order 98-13) 296-307-41031, filed 12/01/98, effective 03/01/99. [Recodified as 296-307-41031. 97-09-013, filed 4/7/97, effective 4/7/97. Statutory Authority: RCW 49.17.040, [49.17.]050 and [49.17.]060. 96-22-048, 296-306A-41031, filed 10/31/96, effective 12/1/96.]

WAC 296-307-41033 How must direct gas-fired tank heaters be constructed and installed? 

Direct gas-fired tank heaters must be constructed and installed as follows:

(1) Direct gas-fired tank heaters, and tanks to which they are applied, must only be installed aboveground.

(2) Tank heaters must be permanently marked with the name of the manufacturer, the rated Btu input to the burner, and the maximum vaporizing capacity in gallons per hour.

Note: Tank heaters may be an integral part of a fuel storage container directly connected to the container liquid section, or vapor section, or both.

(3) Tank heaters must have a means for manually turning off the gas to the main burner and pilot.

(4) Tank heaters must have an automatic safety device to shut off the flow of gas to main burners, if the pilot light should fail. When flow through pilot exceeds 2,000 Btu per hour, the pilot also must have an automatic safety device to shut off the flow of gas to the pilot should the pilot flame be extinguished.

(5) Pressure regulating and pressure reducing equipment if located within ten feet of a direct fired tank heater must be separated from the open flame by a substantially airtight noncombustible partition.

(6) The following minimum distances must be maintained between a storage tank heated by a direct fired tank heater and the nearest important building, group of buildings, or line of adjoining property that may be built on:

(a) Ten feet for storage containers of less than 500 gallons water capacity;

(b) Twenty-five feet for storage containers of 500-1,200 gallons water capacity;

(c) Fifty feet for storage containers of over 1,200 gallons water capacity.

(7) No direct fired tank heater may raise the product pressure within the storage container over 75% of the pressure in the second column of Table U-8.

[Recodified as 296-307-41033. 97-09-013, filed 4/7/97, effective 4/7/97. Statutory Authority: RCW 49.17.040, [49.17.]050 and [49.17.]060. 96-22-048, 296-306A-41033, filed 10/31/96, effective 12/1/96.]

296-307 Part U-2 (Continued)

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