Check valves are an important valve used to prevent the one-way flow of fluid in pipelines to ensure the safe operation of pipelines. However, if used improperly, the check valve may be damaged, resulting in pipeline leakage or unstable fluid pressure, so it is very important to use the check valve correctly.
Before using the check valve, it is necessary to select a suitable check valve model according to the fluid medium to be processed and the working parameters of the pipeline. Check valves of different types and specifications are suitable for different fluid media and pipeline systems, so they must be carefully selected.
Correct installation of the check valve is also a key step in use. During the installation process, the check valve should be installed according to the model and specification of the check valve to ensure that the check valve is installed in the correct position. For gravity check valves, the sewer should be unobstructed, and the valve bracket should be installed horizontally. Vertical installation will cause the valve to be laxly closed, thereby affecting the discharge of the fluid. For spring or pneumatic check valves, the valve should be installed in the exact position of the pipeline, and pay attention to check the working condition of its actuator.
When using a check valve, care should be taken to avoid impact. Impact opening and closing may damage the check valve, so the valve should be operated smoothly to avoid excessive force. When the valve is fully opened, the handwheel should be reversed slightly to tighten the threads to avoid loosening and damage. For rising stem valves, remember the valve stem position when fully open and fully closed to avoid hitting the top dead center when fully open. It is also convenient to check whether it is normal when fully closed. If the valve handle falls off or large debris is embedded between the valve core seal, the valve stem position when fully closed will change.
When operating the check valve, pay attention to some signs. For example, when the groove on the top surface of the valve stem of a ball valve, butterfly valve, or plug valve is parallel to the channel, it indicates that the valve is in the fully open position; when the valve stem rotates 90 degrees to the left or right, the groove is perpendicular to the channel, indicating that the valve is in the fully closed position. The operation of three-way and four-way valves should be carried out according to the opening, closing, and reversing marks. The movable handle should be removed after the operation.
In short, the correct use of check valves is the key to ensuring the safe operation of pipelines. When selecting and using a check valve, you must select a suitable check valve model according to the fluid medium to be processed and the working parameters of the pipeline, and install it according to the correct installation method. During use, you should pay attention to avoid impact, operate the valve smoothly, and pay attention to some signs to ensure the normal operation of the check valve.