When using the manual valve, attention should be paid to the moderate force when the valve is opened, not too much force, so as to avoid accidents. The correct use of manual valves is as follows:
When the valve is fully opened, the handle should be turned a little in the opposite direction to make the threads tight to prevent loosening and damage. Pay attention to the rising stem here, and remember the accurate position of the valve stem when it is fully opened and fully closed, so as to prevent collision with the top dead center when fully opened. It is also helpful to check whether it is no problem when it is fully closed. If the valve disc is loose, or the valve core sealing part is mixed with a relatively large amount of other debris, the position of the rod will change when it is fully closed, resulting in the valve sealing side or the valve hand wheel will also be damaged.
The phenomenon of valve opening: when the groove on the top of the stem of butterfly valve, ball valve and plug valve is parallel to the channel, it means that the valve is in the fully open position; when the valve rod rotates to the left or right by 90 degrees, the groove is vertical to the channel, which means that the valve is in the fully closed position. Some plug valve stem top, butterfly valve, ball valve to channel and wrench into a parallel line for open, vertical for stop. The operation method of three-way and four-way reversing valve should be carried out according to the marks of opening, closing and reversing. After the actual operation, the rotary handle should be removed.
