进口止回阀工作原理

美国欧可止回阀(One-way valve)：止回阀又称单向阀或逆止阀，其作用是防止管路中的介质倒流。水泵吸水关的底阀也属于止回阀类。止回阀按结构划分，可分为升降式止回阀、旋启式止回阀和蝶式止回阀三种。升降式止回阀可分为立式和卧式两种。旋启式止回阀分为单瓣式、双瓣式和多瓣式三种。蝶式止回阀为直通式、以上几种止回阀在连接形式上可分为螺纹连接、法兰连接和焊接三种。 进口止回阀有二种体盖连接设计形式：第一种是体盖螺栓连接锻钢止回阀，按这种连接形式设计的阀门，其阀体与阀盖用螺栓连接，缠绕式垫片密封，优点是便于维修；第二种体盖全焊密封锻钢止回阀，按这种连接形式设计的阀门，其阀体与阀盖用螺蚊连接，全焊密封，优点是无泄漏。

进口止回阀形式种类
止回阀按结构划分，可分为升降式止回阀、旋启式止回阀和蝶式止回阀三种。升降式止回阀可分为立式和卧式两种。旋启式止回阀分为单瓣式、双瓣式和多瓣式三种。蝶式止回阀为直通式、以上几种止回阀在连接形式上可分为螺纹连接、法兰连接和焊接三种。
1、升降式止回阀的结构一般与截止阀相似，其阀瓣沿着通道中以线作升降运动，动作可靠，但流体阻力较大，适用于轻小口径的场合。升降式止回阀可直通式和立式两种。直通式升降止回阀一般只能安装在水平管路，而立式升降止回阀一般就安装在垂直管路。
2、旋启式止回阀的阀瓣绕转轴作旋转运动。其流体阻力一般小于升降式止回阀，它适用于较大口径的场合。旋启式止回阀根据阀瓣的数目可分为单瓣旋启式、双瓣旋启式及多瓣旋启式三种。单瓣旋启式止回阀一般适用于中等口径的场合。大口径管路选用单瓣旋启式止回阀时，为减少水锤压力，最好采用能减小水锤压力的缓闭止回阀。双瓣旋启式止回阀适用于大中口径管路。对夹双瓣旋启式止回阀结构小、重量轻，是一种发展较快的止回阀；多瓣旋启式止回阀适用于大口径管路。
3、隔膜式止回阀有多种结构形式，均采用隔膜作为启闭件，由于其防水锤性能好，结构简单，成本低，近年来发展较快。但隔膜式止回阀的使用温度和压力受到隔膜材料的限制。
4、球型污水止回阀：阀体采用全通道结构，具有流量大、阻力小之优点。采用圆球做阀瓣，适用于高粘度、有悬浮物的工业及生活污水管网
5、蝶式止回阀的结构类似于蝶阀。其结构简单、流阻较小，水锤压力亦较小。

进口止回阀主要特点
1、结构长度短，其结构长度只有传统法兰止回阀的1/4~1/8
2、体积小、重量轻、其重量只有传统法兰止回阀的1/4~1/20
3、阀瓣关闭快速，水锤压力小
4、水平或垂直管道均可使用，安装方便
5、流道通畅、流体阻力小
6、动作灵敏、密封性能好
7、阀瓣行程短、关阀冲击力小
8、整体结构、简单紧凑、造型美观
9、使用寿命长、可靠性高

let check valve working principle

The United States of America Ou check valve ( One-way valve ): check valve also known as a one-way valve or check valve, its role is to prevent the medium in pipeline flow. Pump water off the end of the valve is also a non-return valve. Check valve according to its structure, can be divided into lift check valve, swing check valve butterfly check valve three. Lift check valve can be divided into two kinds of vertical and horizontal. Swing check valve is divided into a single type, double valve and valve type three. Butterfly type check valve for straight-through, above a few kinds of check valve in the form of connection can be divided into the thread, flange connection and welding three. Inlet check valve body cover to connect the design has two forms: the first is a body cover bolt connection forged steel check valve, according to this form of connection of the valve, the valve body with the valve cover bolt connection, spiral wound gasket seal, the advantage of easy repair; the second body cover all welded seal forged steel check valve, according to this form of connection of the valve, the valve body with the valve cover with the screw thread connection, all-welded seal, the advantage of no leakage.

Inlet check valve forms

Check valve according to its structure, can be divided into lift check valve, swing check valve butterfly check valve three. Lift check valve can be divided into two kinds of vertical and horizontal. Swing check valve is divided into a single type, double valve and valve type three. Butterfly type check valve for straight-through, above a few kinds of check valve in the form of connection can be divided into the thread, flange connection and welding three.

In 1, the lift check valve and stop valve structure is generally similar, the valve flap along the channel line to make lifting motion, reliable action, but the fluid resistance, suitable for light and small caliber of the occasion. Lift check valve can be straight and vertical two. Straight through type lifting check valve in general can only be installed in horizontal pipeline, but the vertical lift check valve is usually installed in a vertical pipe.

In 2, swing check valve to rotate around the rotating shaft. The fluid resistance is generally smaller than the lift check valve, which applies to a larger diameter. Swing check valve according to the valve flap can be divided into the number of single swing, double valve swing and multiple valve swing three. Single swing check valves are generally applicable to the medium-calibre occasions. Large diameter pipeline with single swing check valve, to reduce water hammer pressure, the best use can reduce water hammer pressure slow close check valve. Double valve swing check valve for large diameter pipeline. Clip on double valve swing check valve structure of small, light weight, is a rapid development of the check valve; valve swing check valve for large diameter pipeline.

In 3, a diaphragm type check valve has various structural forms, are used as a hoist pieces divide, water hammer because of its good performance, simple structure, low cost, rapid development in recent years. But diaphragm type check valve with temperature and pressure by the diaphragm material.

In 4, ball type sewage check valve : body by the channel structure, with large flow, little resistance of the advantages of. The ball valve valve, suitable for high viscosity, suspended and industrial and domestic sewage pipe network

5, butterfly check valve structure is similar to a butterfly valve. It has the advantages of simple structure, small flow resistance, the water hammer pressure is small.

Inlet check valves major features

1, structure of short length, the length of its structure only traditional flange check valve 1/4~1/8

In 2, small volume, light weight, its weight is only the traditional flange check valve1/4~1/20

In 3, the valve closed quickly, the water hammer pressure small

In 4, a horizontal or vertical pipe can be used, easy installation

5, flow passage, the fluid resistance is small

6, flexible action, good sealing performance

In 7, the valve closing valve of short stroke, small impact force

In 8, the overall structure, has simple and compact structure, handsome in appearance

In 9, long service life, high reliability