排气阀在技术上管件，但通常是作为一个单独的讨论范畴。

Valves are technically pipe fittings, but are usually discussed as a separate category.

youdao

排气阀在技术上管件，但通常是作为一个单独的讨论范畴。

Valves are technically pipe fittings, but are usually discussed as a separate category.

youdao