2·VENT GUARD? Is a protective enclosure designed exclusively for the air release valve found in many public water supply systems.
通风口的保护外壳设计，专用于许多公用水供应系统中的空气释放阀。
3·The valve consists of a guard cage, spring, valve disc, retaining ring and seat. It can be combined with pipe fittings such as reducing couplings, drain elbows, etc.
阀由警戒装置、弹簧、阀碟、扣环和阀座组成，可以和许多管件连接，如缩径管接头、排水弯头等。