斯派莎克BRV73直接作用式减压阀简介
   BRV71和BRV73为球墨铸铁材质的直接作用式减压阀，前者为螺纹连接，或者为法兰连接。主要用于蒸汽系统。结构紧凑，设计简单，表面高质量的无电极涂镍处理。与BRVZ系列减压阀相比，BRV71和BRV73内有压力平衡波纹管，可以平衡主阀头上的压差。主阀为平面密封，具有自清洗功能。
工作原理
   1、开始时，回复弹簧将阀关闭，蒸汽压在阀芯表面及波纹管表面（两者面积相等）施于相等的压力。
   2、如在此时以顺时针的方向转动调压手柄，控制弹簧会因受压而向下迫使阀杆将阀芯推离阀座使蒸汽流通进入下流侧。
   3、下游压力会经阀芯下的感应孔进入感应室迫使控制波纹管向上延伸。同事也向下面的压力平衡波纹管施压消除阀芯背面的下游压力的影响。
   4、当施加在控制波纹管的下游压力大于弹簧的控制力量时，推动主阀杆及阀芯向上移动使阀关闭，在正常情况下，阀会维持在一定的高度，依不同的压力变化和负载条件做小幅度调整
Spirax sarco Introduction
BRV71 and BRV73 as the direct effect of ductile iron valve, which is threaded connection, flange connection or for. Mainly used for steam system. Compact structure, simple design, high quality surface without electrode coated nickel processing. Compared with the BRVZ series valve, BRV71 and BRV73 within apressure balanced bellows, can balance the pressure difference on the main valve head. The main valve is a plane sealing, with self cleaning function.
Working principle
At the beginning of 1, a return spring, the valve is closed, the spool surface and surface vapor pressure bellows (both with equal area) is applied to theequal pressure.
2, as in the time in a clockwise direction of rotation regulating handle, control spring due to pressure forces the stem of the valve core is pushed off from the valve seat so that the steam flow into the downstream.
3, the downstream pressure via the induction hole valve core under theinduction chamber into the corrugated tube extending upward force control.Colleagues pressure balancing corrugated pipe pressure to eliminate theinfluence to the downstream pressure of the valve back.
4, when the control force is applied in the control of downstream pressurebellows is greater than the spring, push the main valve rod and a valve core to move the valve closed, under normal circumstances, the valve will be maintained at a certain height, according to different load conditions andpressure changes in the small adjustment

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。