止回閥的結構與特點止回閥（Check Valve），又稱單向閥或逆止閥，是一種自動閥門。核心功能：依靠管路中介質自身的流動產生的力而自動開啟和關閉，用于防止介質倒流。它是流體管道系統中的“單向通行證”，只允許介質向一個方向流動，阻止反向流動，從而避免泵和驅動馬達反轉、容器介質泄放，以及防止水錘對系統和設備的破壞。按結構形式分類升降式止回閥其結構與截止閥相似，閥體和閥瓣與截止閥相同。閥瓣上部和閥蓋下部加工有導向套筒，閥瓣導向筒可在閥蓋導向筒內自由升降。在閥瓣導向筒下部或閥蓋導向套筒上部加工有泄壓孔，當閥瓣上升時，排出套筒內的介質，降低閥瓣開啟時的阻力。按管道的安裝位置分為以下兩種:

　　Structure and Characteristics of Check Valve Check valve, also known as one-way valve or check valve, is an automatic valve. Core function: It automatically opens and closes by relying on the force generated by the flow of the medium itself in the pipeline, to prevent medium backflow. It is a "one-way pass" in fluid pipeline systems, allowing only one direction of medium flow and preventing reverse flow, thereby avoiding pump and drive motor reversal, container medium release, and preventing water hammer damage to systems and equipment. Classified by structural form, lift check valves have a structure similar to globe valves, with the same valve body and disc as globe valves. The upper part of the valve disc and the lower part of the valve cover are processed with guide sleeves, and the valve disc guide cylinder can be freely raised and lowered inside the valve cover guide cylinder. There are pressure relief holes machined at the lower part of the valve disc guide cylinder or the upper part of the valve cover guide sleeve. When the valve disc rises, the medium inside the sleeve is discharged, reducing the resistance when the valve disc opens. According to the installation position of the pipeline, it can be divided into the following two types:

　　(1)直通式升降止回閥當介質停止流動時，閥靠自重降落在閥座上可阻止介質倒流。

　　(1) When the medium stops flowing, the straight through lift check valve relies on its own weight to land on the valve seat to prevent the medium from flowing back.

　　(2)立式升降止回閥介質進出口通道方向與閥座通道方向相同，其流動阻力小。

　　(2) The direction of the medium inlet and outlet channels of the vertical lift check valve is the same as that of the valve seat channel, and its flow resistance is small.

　　旋啟式止回閥旋啟式止回閥的閥瓣呈圓盤狀，繞閥座通道的轉軸作旋轉運動。由于閥內通道成流線形，流動阻力比直通式升降止回閥小，適用于大口徑的場合。密封性能不如升降式。缺點是關閉時會產生較大水錘壓力，密封面有沖擊和磨損，產生噪音，適用于低流速和流動不常變動的場合，不宜用于脈動流。根據閥瓣的數目多少，旋啟式止回閥又分為以下三種：

　　The disc of a rotary check valve is disc-shaped and rotates around the axis of the valve seat channel. Due to the linear flow inside the valve, the flow resistance is smaller than that of a straight through lift check valve, making it suitable for large-diameter applications. The sealing performance is not as good as that of the lift type. The disadvantage is that it will generate a large water hammer pressure when closed, and the sealing surface will have impact and wear, generating noise. It is suitable for low flow rates and situations where the flow does not change frequently, and is not suitable for pulsating flow. According to the number of valve discs, swing check valves are divided into the following three types:

　　(1)單瓣式，有一個閥座通道和一個閥瓣。適用于中等口徑的旋啟式止回閥。

　　(1) Single disc design, with one valve seat channel and one valve disc. Suitable for medium caliber swing check valves.

　　(2)雙瓣式有兩個閥座通道和兩個閥。適用于較大口徑(DN>600mm)旋啟式止回閥。

　　(2) The double valve has two seat channels and two valves. Suitable for larger diameter (DN>600mm) swing check valves.

　　(3)多瓣式：啟閉件是由多個小直徑的閥瓣組成。介質停止流動時或倒流時，小閥瓣不會同時關閉，可以減弱水力沖擊。由于閥瓣重量輕，關閉動作平穩，所以閥瓣對閥座的撞擊力較小，不會造成密封面的損壞。適用于DN>600mm的止回閥。

　　(3) Multi disc type: The opening and closing component is composed of multiple small diameter valve discs. When the medium stops flowing or flows back, the small valve disc will not close at the same time, which can reduce hydraulic shock. Due to the light weight and smooth closing action of the valve disc, the impact force of the valve disc on the valve seat is relatively small, and it will not cause damage to the sealing surface. Suitable for check valves with DN>600mm.

　　壓緊式止回閥壓緊式止回閥做為鍋爐給水和蒸汽切斷用閥，它具有升降式止回閥和截止閥或角閥的綜合機能。閥桿和閥瓣并不直接連結。僅在鍋爐試壓或停汽時需要關閉閥門，才操作手輪或者當并聯的鍋爐，其中一臺發生故障時，此閥背面壓力增大而關閉，然后再旋轉手輪，將閥瓣壓緊在閥座上。它是開閉和逆止機能同時存在的閥門。

　　Compression type check valve, as a valve for boiler feedwater and steam shut-off, has the comprehensive function of a lift type check valve and a globe valve or angle valve. The valve stem and valve disc are not directly connected. Only when the valve needs to be closed during boiler pressure testing or steam shutdown, should the handwheel be operated or when one of the parallel boilers fails, the pressure on the back of the valve increases and closes, and then the handwheel is rotated to press the valve disc tightly onto the valve seat. It is a valve with both opening and closing functions and check function.

　　其余止回閥還有用于泵吸入管的吸入口處使用的底閥，蝶式止回閥、球式止回閥等。

　　Other check valves include bottom valves used at the suction inlet of pump suction pipes, butterfly check valves, ball check valves, etc.

　　注意事項：(1)直通式升降止回閥應安裝在水平管道上;立式升降止回閥、球式止回閥2和底閥必須安裝在垂直管道上，并要求介質自下而上流動。

　　Attention: (1) The straight through lift check valve should be installed on a horizontal pipeline; Vertical lift check valve, ball check valve 2, and bottom valve must be installed on vertical pipelines, and the medium is required to flow from bottom to top.

　　(2)旋啟式止回閥一般安裝在水平管道上，也可安裝在垂直管道或傾斜管道上。

　　(2) Swing check valves are generally installed on horizontal pipelines, but can also be installed on vertical or inclined pipelines.

　　(3)小口徑管道上選用升降式止回閥，大口徑管道上選用旋啟式止回閥。

　　(3) Lift check valves are used on small-diameter pipelines, while swing check valves are used on large-diameter pipelines.

　　(4)安裝止回閥時要注意介質流動方向與止回閥箭頭指示方向一致。

　　(4) When installing a check valve, pay attention to the direction of medium flow being consistent with the direction indicated by the check valve arrow.

　　本文由  良工閥門 友情奉獻.更多有關的知識請點擊  http://www.hufc.com.cn/   真誠的態度.為您提供為全面的服務.更多有關的知識我們將會陸續向大家奉獻.敬請期待.　　止回閥的結構與特點止回閥（Check Valve），又稱單向閥或逆止閥，是一種自動閥門。核心功能：依靠管路中介質自身的流動產生的力而自動開啟和關閉，用于防止介質倒流。它是流體管道系統中的“單向通行證”，只允許介質向一個方向流動，阻止反向流動，從而避免泵和驅動馬達反轉、容器介質泄放，以及防止水錘對系統和設備的破壞。按結構形式分類升降式止回閥其結構與截止閥相似，閥體和閥瓣與截止閥相同。閥瓣上部和閥蓋下部加工有導向套筒，閥瓣導向筒可在閥蓋導向筒內自由升降。在閥瓣導向筒下部或閥蓋導向套筒上部加工有泄壓孔，當閥瓣上升時，排出套筒內的介質，降低閥瓣開啟時的阻力。按管道的安裝位置分為以下兩種:

　　This article is a friendly contribution from Lianggong Valve For more related knowledge, please click http://www.hufc.com.cn/ Sincere attitude To provide you with comprehensive services We will gradually contribute more relevant knowledge to everyone Coming soon. Structure and Characteristics of Check Valve Check valve, also known as one-way valve or check valve, is an automatic valve. Core function: It automatically opens and closes by relying on the force generated by the flow of the medium itself in the pipeline, to prevent medium backflow. It is a "one-way pass" in fluid pipeline systems, allowing only one direction of medium flow and preventing reverse flow, thereby avoiding pump and drive motor reversal, container medium release, and preventing water hammer damage to systems and equipment. Classified by structural form, lift check valves have a structure similar to globe valves, with the same valve body and disc as globe valves. The upper part of the valve disc and the lower part of the valve cover are processed with guide sleeves, and the valve disc guide cylinder can be freely raised and lowered inside the valve cover guide cylinder. There are pressure relief holes machined at the lower part of the valve disc guide cylinder or the upper part of the valve cover guide sleeve. When the valve disc rises, the medium inside the sleeve is discharged, reducing the resistance when the valve disc opens. According to the installation position of the pipeline, it can be divided into the following two types:

　　(1)直通式升降止回閥當介質停止流動時，閥靠自重降落在閥座上可阻止介質倒流。

　　(1) When the medium stops flowing, the straight through lift check valve relies on its own weight to land on the valve seat to prevent the medium from flowing back.

　　(2)立式升降止回閥介質進出口通道方向與閥座通道方向相同，其流動阻力小。

　　(2) The direction of the medium inlet and outlet channels of the vertical lift check valve is the same as that of the valve seat channel, and its flow resistance is small.

　　旋啟式止回閥旋啟式止回閥的閥瓣呈圓盤狀，繞閥座通道的轉軸作旋轉運動。由于閥內通道成流線形，流動阻力比直通式升降止回閥小，適用于大口徑的場合。密封性能不如升降式。缺點是關閉時會產生較大水錘壓力，密封面有沖擊和磨損，產生噪音，適用于低流速和流動不常變動的場合，不宜用于脈動流。根據閥瓣的數目多少，旋啟式止回閥又分為以下三種：截止閥02

　　The disc of a rotary check valve is disc-shaped and rotates around the axis of the valve seat channel. Due to the linear flow inside the valve, the flow resistance is smaller than that of a straight through lift check valve, making it suitable for large-diameter applications. The sealing performance is not as good as that of the lift type. The disadvantage is that it will generate a large water hammer pressure when closed, and the sealing surface will have impact and wear, generating noise. It is suitable for low flow rates and situations where the flow does not change frequently, and is not suitable for pulsating flow. According to the number of valve discs, swing check valves are divided into the following three types:

　　(1)單瓣式，有一個閥座通道和一個閥瓣。適用于中等口徑的旋啟式止回閥。

　　(1) Single disc design, with one valve seat channel and one valve disc. Suitable for medium caliber swing check valves.

　　(2)雙瓣式有兩個閥座通道和兩個閥。適用于較大口徑(DN>600mm)旋啟式止回閥。

　　(2) The double valve has two seat channels and two valves. Suitable for larger diameter (DN>600mm) swing check valves.

　　(3)多瓣式：啟閉件是由多個小直徑的閥瓣組成。介質停止流動時或倒流時，小閥瓣不會同時關閉，可以減弱水力沖擊。由于閥瓣重量輕，關閉動作平穩，所以閥瓣對閥座的撞擊力較小，不會造成密封面的損壞。適用于DN>600mm的止回閥。

　　(3) Multi disc type: The opening and closing component is composed of multiple small diameter valve discs. When the medium stops flowing or flows back, the small valve disc will not close at the same time, which can reduce hydraulic shock. Due to the light weight and smooth closing action of the valve disc, the impact force of the valve disc on the valve seat is relatively small, and it will not cause damage to the sealing surface. Suitable for check valves with DN>600mm.

　　壓緊式止回閥壓緊式止回閥做為鍋爐給水和蒸汽切斷用閥，它具有升降式止回閥和截止閥或角閥的綜合機能。閥桿和閥瓣并不直接連結。僅在鍋爐試壓或停汽時需要關閉閥門，才操作手輪或者當并聯的鍋爐，其中一臺發生故障時，此閥背面壓力增大而關閉，然后再旋轉手輪，將閥瓣壓緊在閥座上。它是開閉和逆止機能同時存在的閥門。

　　Compression type check valve, as a valve for boiler feedwater and steam shut-off, has the comprehensive function of a lift type check valve and a globe valve or angle valve. The valve stem and valve disc are not directly connected. Only when the valve needs to be closed during boiler pressure testing or steam shutdown, should the handwheel be operated or when one of the parallel boilers fails, the pressure on the back of the valve increases and closes, and then the handwheel is rotated to press the valve disc tightly onto the valve seat. It is a valve with both opening and closing functions and check function.

　　其余止回閥還有用于泵吸入管的吸入口處使用的底閥，蝶式止回閥、球式止回閥等。

　　Other check valves include bottom valves used at the suction inlet of pump suction pipes, butterfly check valves, ball check valves, etc.

　　注意事項：(1)直通式升降止回閥應安裝在水平管道上;立式升降止回閥、球式止回閥2和底閥必須安裝在垂直管道上，并要求介質自下而上流動。

　　Attention: (1) The straight through lift check valve should be installed on a horizontal pipeline; Vertical lift check valve, ball check valve 2, and bottom valve must be installed on vertical pipelines, and the medium is required to flow from bottom to top.

　　(2)旋啟式止回閥一般安裝在水平管道上，也可安裝在垂直管道或傾斜管道上。

　　(2) Swing check valves are generally installed on horizontal pipelines, but can also be installed on vertical or inclined pipelines.

　　(3)小口徑管道上選用升降式止回閥，大口徑管道上選用旋啟式止回閥。

　　(3) Lift check valves are used on small-diameter pipelines, while swing check valves are used on large-diameter pipelines.

　　(4)安裝止回閥時要注意介質流動方向與止回閥箭頭指示方向一致。

　　(4) When installing a check valve, pay attention to the direction of medium flow being consistent with the direction indicated by the check valve arrow.

　　本文由  良工閥門 友情奉獻.更多有關的知識請點擊  http://www.hufc.com.cn/   真誠的態度.為您提供為全面的服務.更多有關的知識我們將會陸續向大家奉獻.敬請期待.

　　This article is a friendly contribution from Lianggong Valve For more related knowledge, please click http://www.hufc.com.cn/ Sincere attitude To provide you with comprehensive services We will gradually contribute more relevant knowledge to everyone Coming soon.