High pressure sewage discharge, double valve front and rear position?
Thread Content
The medium pressure of natural gas, oil, water and powder is 25MPa, which needs to be filtered and drained. It is installed with double valves of ball valve and needle valve. Which one is closest to the filter? effect? Operation precautions? Please help me analyze it, thank you! ·
First of all, why use double valve installation of ball valve and needle valve? We definitely need a suitable reason. When considering it comprehensively, we must consider which is more important, sewage discharge or other functions.
Because the needle valve used in the past was prone to internal leakage, it was caused by impurities.
The ball valve is a cut-off valve, close to the root, and the needle valve controls the flow. It is installed downstream； Open the ball valve first, then open the needle valve, close the ball valve first, then close the needle valve. It is best to add a check valve between the double valves.