For valves, not only installation and regular maintenance, but also operation. Generally, the opening and closing of the valve shall follow the principle of “reverse opening and clockwise closing”. That is to say, turning the handwheel anticlockwise is to open the valve. And turning the handwheel clockwise is to close the valve.
(1) No matter electric valve or pneumatic valve, the manual function is generally consider in the valve design. Which is generally realized by hand wheel or handle. The handwheel or handle of the valve is design according to ordinary manpower, taking into account the strength of the sealing surface and the necessary closing force. Therefore, it is not allow to use long lever or long wrench to pull the valve in the actual operation process.
(2) When opening and closing the valve, the force should be stable and not impact. The impact force has been considered in the design and manufacture of some parts of high-pressure valves which are open and close by impact handwheel. Which can not be equated with general valves. When the valve is fully open, turn the hand wheel back a little, so that the threads are tight to avoid looseness and damage.
(3) When the pipeline is use for the first time, there are many sundries inside. So the valve can slightly open, and the high-speed flow of the medium can use to wash it away. Then it can slightly close and open again, so many times, the dirt can wash away, and then it can be put into normal operation. When the valve is normally open, there may be dirt on the sealing surface. When it is close, the above method shall use to wash it clean, and then it shall formally close.
(4) The sealing surface shall be free of fine seams, otherwise, the medium flows through the fine seams at high speed, and the sealing surface is easy to erod.
(5) When operating the valve, if it is found that the operation is too arduous, the cause shall be analyzed and forced operation is not allow. If the packing is too tight, it can be loosened properly; if the valve rod is skew, the maintenance personnel shall inform for repair.
(6) When operating the high-pressure valve, because the pipeline pressure of the high-pressure valve is very high. When opening, the pressure difference between the front and back of the valve is very large. So the operation must be very careful, and the valve should open slowly and gradually.
(7) Wedge gate valve and stop valve are only use for full opening or full closing, and are not allow to use for regulating and throttling. So as to avoid seal failure cause by erosion or shorten the service life of the valve.