The valve is in the fluid system, the device used to co […]
The valve is in the fluid system, the device used to control the direction, pressure, and flow of the fluid is a device that allows the medium (liquid, gas, powder) in the piping and equipment to flow or stop and can control its flow. The valve is a fluid delivery system An important control component in the
Preparation before operation
Before operating the valve, read the operating instructions carefully. Be sure to know the flow direction of the gas before operation, and pay attention to checking the valve opening and closing signs. Check the appearance of the valve to see if the valve is damp. If there is damp, it should be dried; if there are other problems, it should be dealt with in time, and no malfunction is allowed. If it is an electric valve that has been inactive for more than 3 months, check the clutch before starting. After confirming that the handle is in the manual position, check the insulation, steering and electrical wiring of the motor.
Correct operation method of manual valve
The manual valve is the most widely used valve. Its hand wheel or handle is designed according to ordinary manpower, taking into account the strength of the sealing surface and the necessary closing force. Therefore, you cannot use a long lever or a long wrench to move. Some people are accustomed to using wrenches, so you should pay attention to it carefully. When opening the valve, you should use steady force to avoid excessive force, which may cause opening and closing of the valve. The force should be steady and not impact. Some parts of high-pressure valves with impact opening and closing have considered that this impact force cannot be equal to that of general valves.
When the valve is fully opened, the handwheel should be turned upside down a little to tighten the threads to avoid loosening and damage. For rising stem valves, remember the valve stem positions when fully open and fully closed to avoid hitting the top dead center when fully open. And it is convenient to check whether it is normal when fully closed. If the valve stem falls off, or large debris is embedded between the valve core seal, the position of the valve stem will change when it is fully closed. Damage to the valve sealing surface or valve handwheel.
Valve opening sign: When the groove on the top surface of the valve stem of the ball valve, butterfly valve, and plug valve is parallel to the channel, it indicates that the valve is in the fully open position; when the valve stem rotates 90 left or right. When the groove is perpendicular to the channel, it indicates that the valve is in the fully closed position. Some ball valves, butterfly valves, and plug valves are opened with a wrench parallel to the channel, and closed when vertical. The operation of the three-way and four-way valves should be carried out according to the marks of opening, closing and reversing. After the operation is completed, the movable handle should be removed.