Most compressed gas cylinders require the installation of at least one valve. This valve allows the cylinder to contain gases and allows gas to be filled into or emptied from the cylinder. The cylinder valve is the most vulnerable part of the compressed gas package and requires a thorough understanding in order to maximize its performance. There are three basic valves used in the compressed gas industry. They are the pressure seal valve, the packed valve, and the diaphragm valve. There are several versions or designs within each of the three basic types. This pamphlet will address the more common valves in today’s industry. 大多數壓縮氣體鋼瓶要求安裝至少一個閥門。這個閥門使鋼瓶可以容納氣體，允許氣體灌裝進或提取出鋼瓶。鋼瓶閥門是壓縮氣體包裝的最脆弱的部分。為了最大程度發揮它的作用，要求徹底地理解閥門。在壓縮氣體工業中有三種基本的閥門。它們是壓力密封閥、襯墊閥和隔膜閥。三個基本類型中地每一個還有幾個版本或設計。本手冊將介紹當代工業中最常用的閥門。 .............................................