Sampling valve, as its name implies, is a valve used to obtain media samples for chemical analysis. Generally, it is installed on equipment or pipelines and can be divided into the following types: double opening valve, flange clip valve, and sampling valve with insulation jacket;
Use attention method:
1. The double opening valve is generally composed of two ball valves, which achieves the sampling safety and the purpose of sampling through the linkage in the negative pressure device; when sampling, first close the second valve close to the equipment and pipeline, and open the first valve , Let the medium flow into the space between the two valves; then close the first valve, open the second valve, and place the sampling vessel in the sampling port to hold the medium;
2. The flange clip valve is generally sealed by the cone on the top of the valve stem and the cone hole on the valve seat. When sampling, the valve stem is separated from the cone hole by handwheel rotation, so that the medium can flow from the cone hole to the external sampling vessel;
3. The sampling valve with jacket insulation should pay attention to the following:
I should open the jacket insulation steam to melt the easily crystallized medium in the valve before opening and closing the valve, and do not force the valve to open and close without the medium completely melting;
II When the valve cannot be opened, the method of lengthening the arm cannot be used to open the valve forcibly, because this will cause the valve stem to suffer a large resistance and the valve core to fall off, or cause damage to the sealing surface of the valve stem and the tapered hole, resulting in Damage to the valve or damage to the wrench can cause unsafe factors.