How to operate the manual valve correctly
Release Time:
2022-09-13
Manual valve is a kind of valve commonly used in equipment and devices, which is operated by handle and hand wheel. Generally, the clockwise rotation of the handle and handwheel is defined as the closing direction, and the counterclockwise rotation is defined as the opening direction. However, the opening and closing direction of some valves is opposite to the above, and attention should be paid to checking the opening and closing signs before operation.
For manual valves, the size of the handle and handwheel is designed according to normal man-made. Therefore, it is stipulated in the use of the valve that the operator is not allowed to open and close the valve with the help of levers and long wrenches. At the same time, if the length of the handle and the diameter of the handwheel are less than 320mm, only one person is allowed to operate; the handwheel with a diameter equal to or greater than 320mm is allowed to be operated by two people together, or allowed to be operated by one person with the help of an appropriate lever (generally the length does not exceed 0.5m). However, it is strictly forbidden to use levers or long wrenches for diaphragm valves and non-metallic valves, and it is not allowed to close the valves with excessive or excessive force.
Some operators are accustomed to using levers and long wrenches to operate manual valves, thinking that the greater the closing force, the better, but this is not the case. This will cause premature damage to the valve and even cause an accident. Practice has proved that: except for the impact handwheel, operating the valve too much and too violently is easy to damage the handwheel and handle, scratch the valve stem and sealing surface, and even crush the sealing surface. Secondly, after the handwheel and handle are damaged or lost, they should be equipped in time, and it is not allowed to use an adjustable wrench instead.
Valves such as gate valves and globe valves should be turned 1/4 to 1/2 turn when they are closed or opened to the end (that is, bottom dead center or top dead point), so that the threads can be better sealed, so as to facilitate inspection during operation, so as to avoid screwing. Overtightening will damage the valve.
Some butterfly valves, gate valves and globe valves with larger diameters are equipped with bypass valves. The function of the bypass valve is to balance the pressure difference between the inlet and outlet and reduce the opening torque. When opening, the bypass valve should be opened first, and then the large valve should be opened.
Before opening the steam valve, the pipeline must be preheated to discharge condensed water. Open slowly to avoid water hammer and damage valves and equipment. When opening and closing ball valves, butterfly valves, and plug valves, when the groove on the top surface of the valve stem is parallel to the channel, it indicates the fully open position of the valve; when the valve stem is rotated 90 degrees left or right, when the groove is perpendicular to the channel, Indicates that the valve is in the fully closed position. Some ball valves, butterfly valves, and plug valves are opened when the wrench is parallel to the channel, and closed when the wrench is vertical. The operation of the three-way and four-way valves should be carried out according to the opening, closing and reversing marks, and the movable handle should be removed after the operation is completed.
For gate valves and throttle valves with marking center, check and adjust the indicating position of fully open or fully closed. Rising stem gate valves and globe valves should also adopt their fully open and fully closed positions, so as to avoid hitting the dead point when fully open. When the valve is fully closed, the ruler and mark can be used to find that the closing part has fallen off or resisted foreign objects, so as to troubleshoot.
Newly installed pipes and equipment have a lot of dirt and welding slag inside. Dirt is easy to stick to the sealing surface of the normally open manual valve. The method of slightly opening should be used to let the high-speed medium wash away the foreign matter, and then close gently.
After some manual valves are closed, the temperature drops and the valve parts shrink, causing small gaps on the sealing surface and leakage. In this way, after closing, it should be closed again at an appropriate time.
Whether the valve is operated correctly or not directly affects the service life of the valve.
Tel
ADD
No. 115, Shuangxi Road, Qingyang Economic and Technological Development Zone, Chizhou City, Anhui Province, China
We are committed to:
High, medium and low pressure ball valves, gate valves, globe valves, butterfly valves, steam traps, regulating valves, pressure reducing valves, hydraulic control valves, throttle valves, power station valves, emergency shut-off valves, and other products.
We are committed to:
High, medium and low pressure ball valves, gate valves, globe valves, butterfly valves, steam traps, regulating valves, pressure reducing valves, hydraulic control valves, throttle valves, power station valves, emergency shut-off valves, and other products.
Maintenance and transportation
Service Hotline：
13485660555
SAF Coolest v1.3 设置面板 ATISX-ZYPN-QDADE-AWA
无数据提示
Sorry，当前栏目暂无内容！
您可以查看其他栏目或返回 首页