UL 1769:2016 pdf free download – STANDARD FOR SAFETY Cylinder Valves.
7.8 Nonductile cast iron (regular gray iron) shall not be used for bodies or enclosures for anhydrous ammonia or LP-Gas valves. This does not preclude the use of malleable or nodular iron.
7.9 When corrosion of a part interferes with the intended function of the valve, the part shall be of a corrosion-resistant material or be provided with a corrosion-resistant protective coating.
7.10 A protective coating shall provide resistance against corrosion to a degree not less than that provided by the protective coatings specified in 7.11.
7.11 Cadmium plating shall have a thickness of not less than 0.0003 inch (0.008 mm), and zinc plating shall have a thickness of not less than 0.0005 inch (0.013 mm).
Exception: When threads constitute the major portion of the area of a part, the thickness of the cadmium or zinc plating shall not be less than 0.00015 inch (0.0038 mm).
7.12 When warpage of a casting affects the tightness of gas-confining joints or the proper fit of parts, the casting shall be stress-relieved to reduce the risk of warpage.
7.13 A pressure confining brass part containing more than 15 percent zinc shall be subjected to the Moist Ammonia Air Stress Cracking Test, Section 25.
7.14 Copper or a copper alloy exceeding 67 percent copper shall not be used for a part in contact with acetylene or MPS-Gas.
8 Connections
8.1 The inlet of a valve shall comply with one of the following standards:
a) Compressed Gas Cylinder Valve Outlet and Inlet Connections, CGA V-i, for the gas involved or
b) Pipe Threads, General Purpose (Inch) Revision and Redesignation of ASME/ANSI B2.i- 1968 (R2001), ANSI/ASME B1.20.i.
c) A CGA 793 cylinder valve shall only be constructed with an inlet thread that has a M34 X 1.5 straight thread connection into cylinder and is only to be used on composite cylinders between 2.2 lbs and 19 lbs propane capacity.
Exception: Valves intended for use in installations where pipe fittings incorporate other than NPT type threads shall be permitted to be provided with pipe threads complying with a national pipe thread standard compatible with those fittings. The pipe thread type shall be identified in accordance with 30.10.
8.2 The outlet of a valve shall comply with the Standard for Compressed Gas Cylinder Valve Outlet and Inlet Connections, CGA V-i, for the gas involved.
Exception No. 1: A valve that is marked in accordance with 30.4 is not prohibited from being used with an outlet that complies with one of the following:
a) The Standard for Pipe Threads, General Purpose (Inch) Revision and Redesignation of
ASME/ANSI B2. 1-1968 (R2001), ANSI/ASME B1.20. 1;
b) Automotive Tube Fittings, SAE J512; and
9 Pressure-Relief Devices
9.1 A valve that incorporates a pressure-relief device shall comply with the requirements in the Pressure-Relief Device Standards, Part 1 — Cylinders for Compressed Gases, CGA S-i .1, for the various compressed gases with which it is intended to be used.
9.2 When a pressure-relief device is provided on a valve intended for use with acetylene, a fire test shall also be performed in accordance with the Qualification Procedure for Acetylene Cylinder Design, CGA C-12, and the Procedures for Fire Testing of DOT Cylinder Pressure Relief Device Systems, CGA C-14.
9.3 A dust cap or cover, when provided on a pressure relief valve (Type CG-7 as defined in the Pressure-Relief Device Standards, Part 1 — Cylinders for Compressed Gases, CGA S-1.1) shall not reduce the flow capacity of the relief device. See 19.3.
10 Bodies
10.1 A body shall be provided with a section to serve as a wrench grip.
10.2 Openings for bolts or screws used for assembly shall not extend through the outer walls of a body into the gas-handling section.