膜盒式蒸汽疏水阀（蒸汽压力平衡式）是目前国际上最常用的先进节能型疏水阀。膜盒式蒸汽疏水阀的反应非常灵敏，工作时阀前存有高温凝结水，无蒸汽泄漏，节能效果显著。

　　膜盒式在现如今蒸汽管线中是代替低压（压力在PN25以下）热动力（圆盘式）疏水阀或（压力在PN16以下）双金属片式疏水阀的理想替代品。

Bellows Trap

The main acting unit of bellows trap is metal bellows, which is filled with a type of liquid with gasification temperature lower than water’s saturation temperature. When the device just starts, there appears condensate with low temperature in conduits and the liquid in the bellows is in the condensed state. The trap is turned on. When the temperature of condensate water gradually goes up, the liquid in the bellows begins to vaporize and the pressure within it increases. Consequently, the film drives the valve core to move towards the closing direction. Before the condensate water reaches its saturation temperature, the trap is completely shut down. The bellows controls the opening and closing of valves in accordance with steam temperature changes so as to resist steam and discharge water. Available are two alternative bellows with opening temperature 15℃ or 30℃ lower than saturation temperature.

Bellows trap (with balanced steam pressure) is presently the most commonly used advanced energy-saving traps all over the world. As they are sensitive with high-temperature condensate deposits in front of valves while operating, they boast of remarkable energy-saving effect with no steam leakage.

Bellows trap, among all existing steam pipes, are presently the ideal substitute of low-pressure (with pressure below PN25) hot motive (disc) traps or bimetallic elements traps (with pressure below PN16).

优点：

1、动作速度快，零泄漏。

2、结构简单，维护方便。

3、部件全部采用合金处理的不锈钢，耐磨，耐气蚀，使用寿命长。

4、排空能力强，排水迅速，安装方式随意。

5、可以实现多个膜盒组合，适用于大的排量场合。

6、具有良好的排空气性能，不怕冻，零泄漏，背压率达到75%。

Merits

1.Quick acting speed and zero leakage.

2.Simple structure and convenient maintenance.

3.All components made of alloy-treated stainless steel, resistant to wearing, gas corrosion, long durability.

4.Good emptying capability with quick discharge and easy installation.

5.Capable of combination of multiple bellows, suitable for large discharge.

6.Good air discharge capability, with coldness resistance, zero leakage and backpressure of 75%.

技术参数/Technique parameter

主要零件材料/The materials of primary accessories