蝶式對(duì)夾止回閥的特點(diǎn)：1.蝶形止回閥的閥瓣呈圓盤狀，在閥座通道的旋轉(zhuǎn)軸上進(jìn)行旋轉(zhuǎn)運(yùn)動(dòng)。因?yàn)殚y內(nèi)的通道是流線型的，所以流壓比蝴蝶式止回閥小，適合于低流速和流動(dòng)不大變化的大口徑的情況。蝴蝶式止動(dòng)閥分為單瓣式、雙瓣式和多半式三種。這三種形式主要根據(jù)閥門的口徑來劃分。目的是為了在媒體停止流動(dòng)或逆流時(shí)減弱水力沖擊。2.閥瓣圍繞閥座內(nèi)的銷軸旋轉(zhuǎn)的止回閥。碟式止回閥結(jié)構(gòu)簡(jiǎn)單，只能安裝在水平管道上，密封性較好。3.閥瓣沿著閥體中心線滑動(dòng)的閥門。管道式止回閥是新出現(xiàn)的一種閥門，它的體積小，重量較輕，加工工藝性好，是止回閥發(fā)展方向之一。

The characteristics of butterfly check valve: 1. The valve disc of butterfly check valve is disc-shaped and rotates on the rotating axis of the valve seat channel. Because the channel inside the valve is streamlined, the flow pressure is lower than that of butterfly check valves, making it suitable for large-diameter situations with low flow rates and little change in flow. Butterfly stop valves are divided into three types: single disc, double disc, and half disc. These three forms are mainly divided according to the diameter of the valve. The purpose is to reduce hydraulic shock when the media stops flowing or flows backwards. 2. A check valve in which the valve disc rotates around the pin axis inside the valve seat. The disc check valve has a simple structure and can only be installed on horizontal pipelines, with good sealing performance. 3. A valve in which the valve disc slides along the centerline of the valve body. Pipeline check valve is a newly emerged type of valve, which has a small volume, light weight, and good processing technology, and is one of the development directions of check valves.

這種類型的閥門的作用是只允許介質(zhì)向一個(gè)方向流動(dòng)，而且阻止方向流動(dòng)。通常這種閥門是自動(dòng)工作的，在一個(gè)方向流動(dòng)的流體壓力作用下，閥瓣打開；流體反方向流動(dòng)時(shí)，由流體壓力和閥瓣的自重合閥瓣作用于閥座，從而切斷流動(dòng)。

The function of this type of valve is to only allow the medium to flow in one direction and prevent directional flow. Usually, this type of valve works automatically, and under the pressure of fluid flowing in one direction, the valve disc opens; When the fluid flows in the opposite direction, the pressure of the fluid and the self weight of the valve disc act on the valve seat, thereby cutting off the flow.

內(nèi)螺紋止回閥,蝶式止回閥就屬于這種類型的閥門，它包括旋啟式止回閥和升降式止回閥。旋啟式止回閥有一介鉸鏈機(jī)構(gòu)，還有一個(gè)像門一樣的閥瓣自由地靠在傾斜的閥座表面上。為了確保閥瓣每次大多能到達(dá)閥座面的合適位置，閥瓣設(shè)計(jì)在鉸鏈機(jī)構(gòu)，以便閥瓣具有足夠有旋啟空間，并使閥瓣真正的、與閥座接觸。閥瓣可以全部用金屬制成，也可以在金屬上鑲嵌皮革、橡膠、或者采用合成覆蓋面，這取決于使用性能的要求。旋啟式止回閥在完全打開的狀況下壓力幾乎不受阻礙，因此通過閥門的壓力降相對(duì)較小。升降式止回閥的閥瓣座落位于閥體上閥座密封面上。

Internal thread check valve and butterfly check valve belong to this type of valve, which includes swing check valve and lift check valve. The swing check valve has a hinge mechanism and a valve disc like a door that freely rests on the inclined valve seat surface. In order to ensure that the valve disc can reach the appropriate position on the valve seat surface every time, the valve disc is designed in a hinge mechanism so that the valve disc has sufficient swing space and truly contacts the valve seat. The valve disc can be made entirely of metal, or it can be embedded with leather, rubber, or a synthetic cover on top of the metal, depending on the performance requirements. When the swing check valve is fully open, the pressure is almost unobstructed, so the pressure drop through the valve is relatively small. The valve disc of the lift check valve is located on the sealing surface of the valve seat on the valve body.