UL 1769-2016 pdf download

UL 1769-2016 pdf download.Cylinder Valves.
7 Materials
7.1 An operating or gas-confining pail of a valve shall have the strength and duratlity to provide reliable service of the part and of the assembly.
7.2 To comply with the requirement of 7.1, a material for gas-confining parts of a valve intended for fuel gases shall have a minimum melting point (sobdus temperature) of not less than 1500°F (816°C). A malerial for gas-confining parts of nonfuel gases and operating parts, including handwheels, of fuel gas valves shall have a melting point (solidus temperature) of not less than 950°F (510°C) and a tensile strength of not less than 10.000 psi (68.9 MPa) at 400’F (204°C).
Exception No, 1: A valve to, use with an LP-Gas cylinder not exceeding 240-pound water capacity is permitted to have the safety relief popoet (otscholder) made of a material having a melting point and a tensile strength less than that specified.
Exception No. 2: A valve disc, soft seat, seal ring. diaphragm. or gasket is not requited to co,np4’ with this requirement.
7.3 A part in contact with the gas to be handled shall be resistant to the action of such gas.
7,4 With reference to 7.3 etastomeric materials shall be subjected to the tests noted in (a) (b). and (c)
Polymeric materials shall be subjected to the Accelerated Aging Test, Section 20 and the Fluid
Compatibility Test, Section 22.
a) Accelerated Aging Test. Section 20: For oxygen service, see 7.5.
b) Accelerated Hydrogen Pressure Aging Test, Section 21, if for use with hydrogen,
C) Fluid Compatibllity Test. Section 22: and
d) Low Temperature Test, Section 24.
Exception: Acetal polymers, chloroti’ifluorethylene polymers, telratluorethylene. fluoi’inated ethylene pn,pylene polymers and polyams’des of composition polyhexametty$ene adipamide or polycaproamide polymers (nylon 6, 6.6 or 6/16) shall only be sub,iected to the Accelerated Aging Test. Section 20.
7.5 Organic materials utilized in the gas stream of a valve intended for use with oxygen shall be compatible with oxygen. Elastomeric materials shall be subjected to the test as shown by the Exception to 20.2.
7.6 With reference to the requirement in 7.5. chlorotrifluoroethylene polymers. tetrafluoroethylene, fluorinated ethylene propylene polymers and polyamides of composition polytiexamethylene adipamide or polycaproamide polymers (Nylon 6 or 6116) are permitted without test.
7.7 Ammonia containing minute quantities of water will react rapidly with cadmium, copper, zinc, and many alloys, especially those of copper base. Only Iron. steel, and certain nonferrous alloys, known to be resistant to ammonia service, shall be used in contact with anhydrous ammonia.
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 parl the thickness of the cadmium or zinc plating shall not be less than 000015 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 MPSGas.
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 Rodesignation of ASMEJANSI B2.1. 1968 (R2001), ANSLASME 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.