利用高精度研磨不锈钢空心浮球在阀腔内随着凝结水的液位变化开启或关闭阀门。该疏水阀的结构比较简单，主要由浮球和自动排空装置组成。阀腔内唯一的动作元件——不锈钢空心浮球，采用高精度研磨工艺制造，整个球面均可做密封面，工作时无集中磨损，使用寿命长 ; 阀腔内无易损件，可靠性高。浮球能根据水位变化而自由调节阀孔的开度，能够连续排放凝结水，过冷度≈0℃，工作效率高。

　　自动排空装置分为两种 :（低压PN25以内）液囊热敏元件组成和（过热蒸汽系统）双金属片组成。

Free-ball float trap

The drain valve is opened or closed by taking advantage of the change of liquid level of condensate water with the high-precision grinding stainless steel hollow float ball in the valve cavity. This steam trap has a simple structure, mainly consisting of float balls and automatic emptying devices. The sole action elements, namely, the stainless steel hollow float ball is manufactured by high-precision grinding process, and its entire sphere can serve as the sealing face and will not be worn intensively during the work, so it has a longer service life. In addition, there is no wearing part in the valve cavity, with a high reliability. The float ball can freely adjust the openness of the valve opening in response to the change of water level and discharge the condensate water continuously with a subcooled temperature of about 0℃ and higher efficiency.

The automatic emptying devices fall into two types : (within low pressure PN25) consisting of reservoir thermo-sensitive elements and (overheated steam system) consisting of bimetals.

优点：

1、唯一转动的是高精度研磨的不锈钢浮球，抗腐蚀。

2、结构简单，维修方便。

3、不受压力波动的影响，连续排水，噪声小。

4、装有自动排空装置，能够迅速排除空气，防止气堵和汽锁。

5、体积小，排量大。

6、有水就排，能够加快系统启动速度。

Merits

1. The sole moving component is the high-precision grinding stainless float ball, which can resist erosion.

2. Its simple structure is convenient for maintenance.

3. To drain continuously with low noise, without being affected by the fluctuation of the pressure.

4. To be equipped with automatic emptying devices and it can eliminate air quickly and prevent air blocking and steam locking.

5. Small volume and large displacement.

6. To drain whenever there is water left over so as to quicken the startup speed of the system.

主要零件材料/The materials of primary accessories

不锈钢球直径/Diameter of stainless ball

工作原理说明：

在设备刚启动时，低温冷凝水和空气同时进入阀腔，这时开启自动排空装置将空气排除，使低温凝结水顺利进入阀腔，阀腔内的凝结水的液位随即上升，使浮球升高，开启阀孔，将凝结水迅速排出 ; 前面的蒸汽很快进入加热设备，使设备迅速加热升温，当蒸汽或较高温度的凝结水进入阀腔时，自动排空装置开始膨胀，关闭自动排空气装置，疏水阀开始正常工作。这时阀腔内的浮球随凝结水液位的高低而升降，能连续的排放凝结水。由于自由浮球式疏水阀的阀座孔总处于凝结水液位以下，形成水封，水汽自然分离，工作时达到无蒸汽泄漏。该阀的最小工作压力为0.01Mpa，从0.01Mpa至最高工作压力范围内不受温度和工作压力波动的影响，能连续工作，其最小过冷度约为0℃，由于该阀能自动、连续地排除凝结水，加热设备内不会有水积聚，能使加热设备达到最佳换热效率。是生产工艺加热设备的最理想疏水阀之一。