pid problem
Thread Content
Teachers, may I ask why there are grade divisions in the regulating valve group and what their function is?
This is normal. Generally, when doing process design, the pipeline pressure level will be divided at the outlet of the regulating valve and the outlet of the safety valve. The flanges, pipes, etc. used are also implemented according to the corresponding grades.
The boundary is where there is a pressure change.
The pressure before and after the pressure reducing valve is different, and the bypass valve is generally closed, so the levels before and after the bypass valve are different.
This means that the media before and after the control valve have different material requirements due to factors such as temperature and pressure. The materials before and after the control valve have been upgraded.
Users who need to connect behind the material boundary may need stainless steel or other materials, but the material coming from the boundary area may be carbon steel or other materials. The flange valve is usually used as the dividing point, and the actual design shall prevail.
Whether the material changes or not cannot be seen on the pid
This is obviously because the material has changed and from the picture it should be reduced from stainless steel to carbon steel. The pressure level has not changed.