UL 144-2021 pdf download – LP-Gas Regulators.
6.6 OVERPRESSURE SHUTOFF (OPSO) FEATURE – A feature that shuts off the flow of LP-Gas vapor when the outlet pressure of the regulator reaches a predetermined maximum pressure. 6.7 REGULATOR: a) AUTOMATIC CHANGEOVER REGULATOR – An integral two-stage regulator that combines two high-pressure regulators and a second-stage regulator into a single unit. It incorporates two inlet connections that is designed for use with dual or multiple cylinder installations. The system automatically changes the LP-Gas vapor withdrawal from the designated service cylinder(s) to the designated reserve cylinder(s) without interruption of service. It incorporates a service-reserve indicator or provision for attachment of a service-reserve indicator. The service-reserve indicator gives a visual indication of the cylinder(s) that are supplying the system. A switching device is manually selected to alternate between the service and reserve cylinders. b) FIRST-STAGE REGULATOR – A type of high-pressure regulator for LP-Gas vapor service designed to reduce pressure from the container to a nominal pressure of 13.7 – 68.7 kPa (2 – 10 psig). c) HIGH-PRESSURE REGULATOR – A pressure regulator for LP-Gas liquid or vapor service designed to reduce pressure from the container to a lower pressure in excess of 6.9 kPa (1.0 psig). d) INTEGRAL 13.8 KPA (2 PSIG) SERVICE REGULATOR – A pressure regulator that combines a high-pressure regulator and a 13.8 kPa (2 psig) 13.8 kPa (2 psig)service regulator into a single unit. e) INTEGRAL TWO-STAGE REGULATOR – A pressure regulator that combines a high-pressure regulator and a second-stage regulator into a single unit. f) MANUAL CHANGEOVER REGULATOR – A single-stage regulator with a manifold that contains two inlets that allow LP-Gas to flow from one inlet or the other using a handle or lever through the single-stage regulator to the gas consuming equipment. It is designed to be used with two LP-Gas containers.
10 Bodies and Bonnets 10.1 T body and a bonnet of a regulator or a manifold shall withstand the stresses of connecting the regulator or manifold to piping, as well as other stresses imposed by service conditions, without developing leakage at joints, permanent deformation, or other damage which impairs the serviceability of the regulator or manifold. See Section 20, Deformation Test, Section 26, Strength of Body Test, and Section 33, Endurance Test. 10.2 A body of a service indicator shall withstand the stresses of connecting the indicator to piping or tubing. See Section 20, Deformation Test, and Section 35, Service-Reserve Indicator Endurance Test. 10.3 Any flanges of a body and a bonnet of a regulator or manifold constructed to be clamped together shall withstand the stresses imposed by normal tightening of the clamping screws or bolts. Clamping screws or bolts shall be spaced sufficiently close together so as to preclude the necessity of using excessive force in tightening to obtain joints that are tight against leakage. See Section 22, Leakage and Strength of Mechanism Test, and Section 26, Strength of Body Test. 10.4 When warping of a casting-affects the tightness of gas -confining joints or the required fit of parts, the part shall be stress-relieved to reduce the risk of warping. See Section 22 Leakage and Strength of Mechanism Test.