Attentions of valve products in work

The valve is an important component in the thermal system. The operating personnel often have to deal with the valve, so they are familiar with and master the structure and performance of the valve, correctly identify the valve direction, opening sign, and indication signal, and should be able to adjust and operate the valve in a skilled and accurate manner. Handle various emergency failures decisively. Pay attention to the following categories during operation:

1. Identify the switching direction of the valve. In general manual valves, the clockwise rotation direction of the handwheel indicates the valve closing direction, and the counterclockwise direction indicates the valve opening direction. There are some valve directions opposite to the above opening and closing. Check the opening and closing signs before operation, and then operate the plug valve. The groove is parallel to the channel, indicating that the valve is in the fully open position. When the valve stem rotates 90 °, the groove is perpendicular to the channel, indicating that the valve is in the fully closed position. Some plug valves are opened with a wrench parallel to the channel, and closed vertically. The operation of three-way and four-way valves should be carried out according to the opening and closing reversal marks.

2. Appropriate force is required. When operating the valve, excessive force may cause damage to the handle, hand wheel, valve stem and sealing surface, or even crush the sealing surface. Large, damaged valve.

3. Before opening the steam valve, first preheat the pipeline to remove condensate, and open slowly when opening to avoid water hammer and damage to the valve and equipment.

The larger-diameter valve is equipped with a bypass valve. When opening, the bypass valve should be opened first. After the pressure difference between the two sides of the valve decreases, the large valve should be opened. When closing, first close the bypass valve, then close the large valve.

Gate valves and globe valves are fully opened, and they must be turned 1 / 4—1 / 2 turn, which is beneficial to the operation check, so as not to over-tighten and damage the valve.