Sampling valves, as the name suggests, are valves used to obtain media samples for chemical analysis. They are roughly divided into the following types: double opening valves, flange clip valves, and sampling valves with insulation jackets.
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 matters: I should open the jacket insulation steam to melt the easily crystallized medium inside the valve before opening and closing the valve. Do not force the valve to open and close without the medium completely melting; II When When the valve cannot be opened, the method of lengthening the arm can not be used to force the valve to open, because this will cause the valve stem to be subject to greater resistance and the valve core to fall off, or cause the valve stem and the sealing surface of the tapered hole to be damaged, resulting in valve damage. Or cause damage to the wrench and cause unsafe factors. If you have any questions, please contact us.
Practice has learned: At present, most of the scenes are welded with a DN15 globe valve at the process pipeline head, and then a needle valve or DN6 \ DN8 ball valve is installed behind the valve.