Types of check valve

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The check valve is a kind of valve that depends on the medium flow itself to open and close automatically to prevent the reverse flow, also known as the reverse valve, one-way valve, non-return valve(NRV) and backpressure valve. The purpose of the check valve is to prevent reverse flow of the medium, to prevent the pump and drive motor from reversing, and to prevent the release of the container medium. When the fluid flows in the specified direction, the pressure of the fluid causes the disc to open, but when the fluid flows in the opposite direction, the pressure of the fluid and the self-aligning disc work together on the seat to prevent backflow, and can also be used to supply the auxiliary system where the pressure may rise above the system pressure. According to the structure, the check valve can be divided into swing check valve, wafer check valve, lift check valve, vertical check valve, double check valve, butterfly check valve, ball type check valve, Y type check valve.

 

Swing check valve

Swing check valves are divided into single-disc, double-disc and multi-disc check valves. The round disc around the seat axis moves for rotary, flow resistance is small because of the streamlined valve inside the channel, suitable for low flow rate and flow is not often changed in large-caliber pipeline. To ensure that the disc reaches the seat face in the proper position each time, the disc is designed in a hinged mechanism so that the disc has sufficient swing space and is in full contact with the seat. The disc may be made entirely of metal, may be covered with leather and rubber, or made by cladding cover, that depending on performance requirements.

 

Lift Check Valves

Lifting check valve can be divided into vertical and straight through according to the structure. The lift check valve disc is located on the seat sealing face, similar to the globe valve, the fluid pressure causes the disc to rise from the seat sealing face, the medium backflow causes the disc to fall back to the seat and cut off the flow. A vertical lift check valve is generally used in a nominal 50mm horizontal pipe. Straight-through lift check valves can be installed in both horizontal and vertical pipelines. The bottom valve is generally only installed on the vertical pipe at the sump pump, and the medium flows from bottom to top. The sealing performance of lift check valve is better than that of swing check valve.

 

Butterfly check valve

Also known as the wafer check valve, generally, straight through, the butterfly check valve is suitable for low pressure, large diameter and installation are limited occasions. Because the butterfly check valve’s working pressure is not high, generally below 6.4mpa, but the nominal diameter can reach more than 2000mm.The installation position of the wafer type check valve is not restricted. It can be on the horizontal pipeline, or on the vertical or on the inclined pipeline.

 

Diaphragm check valve
The diaphragm check valve is suitable for pipeline that easy to produce water hammer, the diaphragm can be very good to eliminate the water hammer effect when the medium countercurrent. Limited by the material of diaphragm, the diaphragm check valve is generally used in low-pressure normal temperature pipelines, especially in the water pipeline. The working temperature of the medium is -20 ~ 120℃ and the working pressure is less than 1.6mpa, and the diameter can reach up to 2000mm. Due to its excellent waterproof performance, simple structure and low manufacturing cost, it has been widely used in recent years.

 

 

Development of high pressure critical hydrogen valve

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Recently, PERFECT factory produced a small batch of high-pressure hydrogenation valves. High-pressure hydrogenation is an important process in petroleum deep processing and coal chemical industry. It can not only improve the recovery rate of crude oil but also improve the quality of fuel oil. The dielectric environment of a high-pressure hydrogenation device is characterized by high pressure and hydrogen (with hydrogen sulfide), with flammable and explosive high-pressure gases (hydrogen or hydrocarbon + hydrogen) which store large pressure energy. Once its storage and transportation equipment (including pipeline valves) damage will cause a catastrophic safety accident.

Hydrogen can cause a number of different adverse effects in metallic materials. It can penetrate into the metal material and cause material embrittlement and deformation at normal temperature. Hydrogen sulfide corrosion of metal materials is a very difficult problem, it can cause stress corrosion cracking of metal materials at room temperature and high temperature. All these features have required a strict need for material, structural design and strength design of high-pressure hydrogenation valve. Therefore, the high-pressure hydrogenation valve must face the problems of hydrogen embrittlement and hydrogen corrosion and must pay attention to the problem of leakage under high-temperature and high-pressure conditions. Valves with high-pressure hydrogenation, generally including ball valves, gate valves, globe valves, check valves and plug valves, ASME CL900~2500, room temperature to 400℃.

Valves used in industrial hydrogen applications like petrochemical processes are often made of Cr-Mo steel and Inconel alloy. The main materials of high-pressure hydrogenation valve are A182 F11/F22/F321, A216 WCB, A217 WC6 / WC9, A351 CF8C, Inconel 725 with a diameter DN15-400 mm.

The design and manufacture of hydrogenation valves shall conform to API 600, API 602, BS 1868, BS 1873, ASME B16.34, NACE MR0175, NACE MR0103 and this standard. Our manufacturing center has the ability to produce high-pressure hydrotreating valves and has been successfully applied in hydrotreating equipment (operating pressure 8~10 MPa). More information, call for us today!

New products: Intelligent voice-activated valve

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There are too many types of valve in industrial fields. Intelligent valve transmission command information through digital communication and network, such as valve opening, operation times, operation speed, output torque and other valves. It can remotely set the valve opening range, change valve characteristics, adjust blind area and remote adjustment.

The PERFECT factory has developed a unique intelligent voice-controlled valve. The in-ear earphone has the ability to sense the environment and can connect the external cavity of the earphone with the internal cavity. Most products on the market receive external sound through the electrical signal of the microphone, which will increase the power consumption, while the first miniature acoustic control valve will not. Due to the fact that the micro-acoustic electronic valve is a physical channel, the ambient sound received by it has not been processed twice. Compared with the electrical signal of the microphone, it sounds more natural without delay and distortion.

Over the past years, PERFECT has cooperated with many research and development institutions to make every product in good faith. With our unique technical advantages and rich production experience, coupled with strict product testing, our company has always been committed to providing innovative solutions to optimize the user experience.