（a） 本标准涵盖标称阀门尺寸½至12的手动热塑性阀门。这些阀门适用于地下热塑性燃气分配总管和服务管线。此类分配管道系统可能运行的最大工作压力（MOP）与天然气和其他天然气的管道输送一致；最低安全标准[49 C.F.R.]。， §192（2017）]，适用于-20°F至140°F（-29°C至60°C）的温度范围。（b） 本标准规定了每个基本阀门设计的资格要求，作为证明符合本标准的必要条件。（c） 本标准规定了用于燃气[包括合成天然气（SNG）]和液化石油气（LP）或其混合物地下管道系统的新制造阀门的要求。

(a) This Standard covers manually operated thermoplastic valves in nominal valve sizes ½ through 12. These valves are intended for use below ground in thermoplastic fuel gas distribution mains and service lines. The maximum operating pressure (MOP) at which such distribution piping systems may be operated is in accordance with Transportation of Natural and Other Gas by Pipeline; Minimum Safety Standards [49 C.F.R., §192 (2017)] for temperature ranges of –20°F to 140°F (–29°C to 60°C).(b) This Standard sets qualification requirements for each basic valve design as a necessary condition for demonstrating conformance to this Standard.(c) This Standard sets requirements for newly manufactured valves for use in below-ground piping systems for fuel gas [includes synthetic natural gas (SNG)] and liquefied petroleum (LP) gases (distributed as a vapor, with or without the admixture of air) or mixtures thereof.