利用高精度研磨不銹鋼空心浮球在閥腔內隨著凝結水的液位變化開啟或關閉閥門。該疏水閥的結構比較簡單，主要由浮球和自動排空裝置組成。閥腔內唯一的動作元件——不銹鋼空心浮球，采用高精度研磨工藝制造，整個球面均可做密封面，工作時無集中磨損，使用壽命長 ; 閥腔內無易損件，可靠性高。浮球能根據水位變化而自由調節閥孔的開度，能夠連續排放凝結水，過冷度≈0℃，工作效率高。

　　自動排空裝置分為兩種 :（低壓PN25以內）液囊熱敏元件組成和（過熱蒸汽系統）雙金屬片組成。

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.

優點：

1、唯一轉動的是高精度研磨的不銹鋼浮球，抗腐蝕。

2、結構簡單，維修方便。

3、不受壓力波動的影響，連續排水，噪聲小。

4、裝有自動排空裝置，能夠迅速排除空氣，防止氣堵和汽鎖。

5、體積小，排量大。

6、有水就排，能夠加快系統啟動速度。

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

不銹鋼球直徑/Diameter of stainless ball

工作原理說明：

在設備剛啟動時，低溫冷凝水和空氣同時進入閥腔，這時開啟自動排空裝置將空氣排除，使低溫凝結水順利進入閥腔，閥腔內的凝結水的液位隨即上升，使浮球升高，開啟閥孔，將凝結水迅速排出 ; 前面的蒸汽很快進入加熱設備，使設備迅速加熱升溫，當蒸汽或較高溫度的凝結水進入閥腔時，自動排空裝置開始膨脹，關閉自動排空氣裝置，疏水閥開始正常工作。這時閥腔內的浮球隨凝結水液位的高低而升降，能連續的排放凝結水。由于自由浮球式疏水閥的閥座孔總處于凝結水液位以下，形成水封，水汽自然分離，工作時達到無蒸汽泄漏。該閥的最小工作壓力為0.01Mpa，從0.01Mpa至最高工作壓力范圍內不受溫度和工作壓力波動的影響，能連續工作，其最小過冷度約為0℃，由于該閥能自動、連續地排除凝結水，加熱設備內不會有水積聚，能使加熱設備達到最佳換熱效率。是生產工藝加熱設備的最理想疏水閥之一。