Spirax-Sarco valve mechanism for B4 series 15lb.inverted bucket steam trap.
 
Spirax-Sarco valve mechanism less bucket is the device that allows the condensate and air to drain from the trap. The mechanism is a lever and seat operation, it is held in place by screwing the seat into the outlet port within the trap. With the inverted bucket attached to this mechanism, the steam pressure within the bucket keeps the lever up in turn keeping the seat closed when steam is present. When the steam cools and turns to a liquid state (condensate), the trap fills with condensate causing the bucket to drop and this opens the seat to allow the condensate and air to drain.
斯派莎克直接作用式减压阀BRV73阀门机制B4系列15lb.inverted吊桶式疏水阀。 
 
斯派莎克直接作用式减压阀BRV73机构少铲斗装置，使冷凝水和空气从陷阱排出。该机构是一个杠杆和座椅的操作，它在适当的位置通过螺纹连接在座椅进入出口端口陷阱内举行。与连接到这个机制倒斗，斗内的蒸汽压力保持杆，反过来保持座位关闭时蒸汽存在。当蒸汽冷却并变成液体状态（冷凝），陷阱充满冷凝水造成杯水车薪，这将打开座椅，让冷凝水和空气排出。