UL 252A:2010 pdf download

UL 252A:2010 pdf download.Compressed Gas Regulator Accessories.

CONSTRUCTION
5 Assembly
5.1 An accessory shall include all of the components required for its intended operation and installation,
and shall be assembled as a single unIt.
5.2 An accessory intended to be repaired shall be constructed so that parts are capable of being
reassembled after being dismantled, to the extent required for routine maintenance.
5.3 A seat disc shall be attached to its poppet or holder, or otherwise assembled to prevent it from becoming dislocated under service conditions. The means to secure the disc shall not rely on cement or adhesive.
5.4 A shut-off valve shall not be equipped with a means to prevent it from closing completely.
6 Materials
6.1 A material in contact with the gas to be handled shall be resistant to the action of such gas.
6.2 With reference to the requirement in 6,1 chlorotrifluoroethytene polymers. tetraflueroethylene. and fluorinated ethylene propylene polymers are capable of being used with oxygen.
6.3 Unalloyed copper or a copper alloy exceeding 67 percent copper shall not be used for parts In contact with acetylene or methylacetylene-propadiene stabilized (MPS),
Exception: Alloys used for bourdon tubes of gauges and inlet filters shall not contain more than 95 percent copper.
6.4 Nonductale cast iron (regular gray iron) shall not be used for bodies or enclosures for LP-Gas valves. This does not preclude the use of malleable or nodular iron.
6.5 When atmospheric corrosion of a part interferes with the intended function of an accessory, the part shall be of a corrosion-resistant material, such as stainless steel or brass, or be provided with a corrosion-resistant protective coating.
6.6 A protective coating shall provide resistance against corrosion to a degree not less than that provided by the coatings specified in 6.7. See the Comparative Corrosion Test, Section 15.