Types and principles of check valves
Check valve refers to a valve whose opening and closing parts are circular discs and rely on its own weight and medium pressure to generate actions to block the back flow of the medium. It is an automatic valve, also called check valve, one-way valve, return valve or isolation valve. The movement of the disc is divided into lift type and swing type. The lift check valve is similar in structure to the stop valve, but lacks the valve stem to drive the valve disc. The medium flows in from the inlet end (lower side) and flows out from the outlet end (upper side). When the inlet pressure is greater than the sum of the weight of the disc and its flow resistance, the valve is opened. On the contrary, the valve is closed when the medium flows back. The swing check valve has a disc that is inclined and can rotate around an axis.
Ball Check Valve
Ball Check Valve is a check valve with multi-ball, multi-channel, and multi-cone inverted flow structure. It is mainly composed of front and rear valve bodies, rubber balls, and cones.
How Ball Check Valve works
The rubber ball rolls in the ball cover for a short stroke to realize the opening and closing of the valve. When the water pump starts, the water blows open the rubber ball under the action of pressure, so that the rubber ball rolls to the right side. The cone in the rear valve body fixes its position, and the check valve opens; after the pump stops, due to the pressure in the pipeline system The back water pressure forces the rubber ball to roll to the front valve body on the left side to close the check valve. The rubber ball is made of hollow steel ball, and the rubber with good elasticity can not only ensure the sealing, but also reduce the damage to the pipeline system during the valve closing process. The cone-shaped body with holes fixes the steel ball when the valve is opened and eliminates the pressure of the contact area between the rubber ball and the cone-shaped body, making the contact surface contact, reducing the hydraulic loss caused by the shaking of the rubber ball in the valve body.
Advantages of Ball Check Valve
Long service life, stable operation, safe and reliable, and good sealing performance;
The drag coefficient is small. Because it is a ball valve, the water flow almost straight through the valve body;
The shock absorption effect is good, and the water quality requirements are not strict.
Foot Check Valve
Foot Check Valve, also known as a check valve, is a low-pressure flat valve. Its function is to ensure the one-way flow of the liquid in the suction pipe and make the pump work normally. When the pump stops working intermittently for a short time, the liquid cannot return to the water source tank. Ensure that the suction pipe is filled with liquid to facilitate the start of the pump.
Advantages of Foot Check Valve
1. The structure is ideal both in terms of flow rate and process requirements. In addition, it will not produce turbulence when emptying.
2. It can provide all current international standard interfaces, such as welding type, clamp type or thread type, etc.
3. The valve body materials are US304.SUS316L. Of course, other alloy steels can also be used according to customer requirements.
4. The surface of the valve body can be mechanically polished or electro-polished according to customer requirements, and the accuracy can reach 0.25um.
5. Foot Check Valve can be equipped with manual or pneumatic. Each pump needs to install a Foot Check Valve. The Foot Check Valve is usually installed below the water surface, while the water-based Foot Check Valve is installed above the water surface. It is an old-fashioned Foot Check Valve's updated products are ideal water diversion equipment and can replace vacuum pumps and vacuum devices.
Foot Check Valve has reasonable design, advanced manufacturing technology, and convenient installation, use and maintenance. And has the advantages of low friction resistance, long service life, energy saving, etc., and is widely used in water pump supporting facilities in petrochemical, chemical, textile, printing and dyeing, metallurgy, mining, irrigation and drainage industries.
In addition to the above products, we can also provide Flapper Check Valve, Foot Check Valve, and DI Slient Check Valve.