Author: Site Editor Publish Time: 2018-09-21 Origin: Site
We will find following difference between ball valve and check valve: advantage of ball valve and check valve, structure, sealing performance type, etc.
The ball valve is a valve that uses a ball with a circular through hole as a starting and closing member, and the ball rotates with the valve stem to realize the opening and closing action. The main function of the ball valve is to cut off and close the medium circulation passage in the pipeline. The working principle is to rotate the sphere by 90° by means of a handle or other driving device, so that the through hole of the sphere coincides with or perpendicular to the center line of the valve body passage to complete the valve.
(1) The fluid resistance is small. When the valve is fully open, the cross-sectional areas of the ball passage, the valve body passage and the connecting pipe are equal, and the wires are in a straight line, and the medium flows through the ball valve, which is equivalent to flowing through a straight pipe. The valves through which the resin passes in the water system are generally ball valves.
(2) Quickly open and close, only need to turn the ball 90° when opening and closing, which is convenient and rapid.
(3) The structure is simple, the volume is small, and the quality is light. In particular, its height is much smaller than the gate valve and the globe valve.
(4) Good sealing performance. Ball valves generally use a soft, flexible seal.
The check valve is a valve that automatically prevents the fluid from flowing backwards, also known as a check valve. The valve flap of the check valve is opened under fluid pressure, and the fluid flows from the inlet side to the outlet side. When the inlet side pressure is lower than the outlet side, the valve flap is automatically closed under the influence of the fluid pressure difference and its own gravity to prevent the fluid from flowing backward.
Check valves are typically used for the outlet of the pump. Check valves are generally divided into lift type, swing type, butterfly type and diaphragm type.
The structure of the lift check valve is generally similar to that of the globe valve. The valve flap moves up and down along the center line of the passage, and the action is reliable, but the fluid resistance is large, which is suitable for occasions with a small diameter.
The valve flap of the swing check valve rotates around the rotating shaft, and its fluid resistance is generally smaller than that of the lift check valve, which is suitable for a large diameter.
The butterfly check valve is similar to the butterfly valve, and has a simple structure, a small flow resistance, and a small water hammer pressure.
1. The check valves can adopt a pressure self-tightening sealing structure, and the ball valve requires an external force;
2. The check valves flap limiting device prevents the flap opening position from being too high to be closed;
3. The solid pin of the check valve is installed accurately and has high strength, which ensures the service performance and service life of the valve;
4. The rocker has sufficient strength and there is enough freedom when closing to facilitate the closing of the valve flap.
5. The check valve has sufficient strength and rigidity. The valve sealing surface can be welded with metal materials or inlaid with non-metal materials according to user requirements.