UL-495:2016 pdf free download – STANDARD FOR SAFETY Power-Operated Dispensing Devices for LP-Gas.
12 Meters
12.1 A meter shall be provided downstream from the strainer.
13 Vapor Separators
13.1 A vapor separator shall comply with the requirements in 13.2 and 13.3 and in the High-Pressure Leakage Test, Section 26, and the Hydrostatic Strength Test, Section 27.
13.2 A vapor separator shall be arranged for connection of piping to return vapors that may be formed to the LP-Gas supply tank. The vapor shall be returned from the separator to the supply tank through an orifice not larger than No. 54 drill size, an orifice larger than No. 54 drill size that is protected by an excess flow check valve, or a float-controlled orifice.
13.3 The float and related parts shall comply with the requirements in 5.10 and in the Float Crushing Test, Section 29.
14 Valves
14.1 A shutoff valve or equivalent device shall be provided in the liquid-inlet and vapor-outlet piping of each device. The valves shall be installed to permit the complete dispensing device to be temporarily moved so that components can be repaired or replaced if necessary.
14.2 A shutoff valve or valves shall be provided to vent to the atmosphere all the LP-Gas contained in the dispenser piping. The valve shall have means for connection to vent piping, which may be manifolded.
14.3 A shutoff valve shall be installed in the piping ahead of the hose connection of each dispensing device supplied by a remote pump to relieve the hose of pump pressure when another dispenser served by the same pump is in operation. The valve shall be interconnected with the control mechanism so that the valve will be closed when the motor-control switch is moved to the off position. Conversely, the valve shall be opened when the motor-control switch is moved to the on position.
14.4 A hose-nozzle valve or fuel-transfer valve shall be provided for each discharge hose. The valve shall be compatible with the dispensing-device locking mechanism.
14.5 A hydrostatic relief valve provided to comply with the requirements in 10.1 and 10.2 shall have a pressure setting of not more than 400 psig (2.76 MPa).
14.6 An excess-flow check-valve, automatic shutoff valve, or differential back pressure valve shall be installed in the fuel supply piping at the inlet to the dispensing hose. The hose, piping, and fittings on both sides of the excess-flow check valve shall have a flow rating greater than the valve itself. Any valve or fuel supply piping shall include a shear section reduced in thickness by 20 percent at the outlet end and shall be mounted so that any break in the valve or piping under abnormal conditions will occur at the shear section so that the valve mechanism will not be damaged. A separate fitting, such as an emergency pullaway fitting, installed at the inlet of the dispensing hose, shall be used in conjunction with the excess-flow check valve, automatic shutoff valve or differential back pressure valve.
14.7 A plug or rotating-disc type valve, in which the bearing surface of the plug or disc provides the seal to the exterior of the valve body, shall not be used in liquid lines.
14.8 An electrically operated shutoff valve shall close upon being de-energized, regardless of the position of any operating lever or reset handle.
15 Piping and Fittings
15.1 Joints in wrought iron, steel, brass, or copper pipe may be threaded, welded, or brazed. Pipe threads shall be in accordance with the Standard for Pipe Threads General Purpose (Inch), ANSI/ASME B1 .20.1.