Can the high-pressure shut-off valve of a pressure gauge have its seal ring replaced online?
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The hydrocracking unit is equipped with several pressure gauge shut-off valves of class 1500; there is slight leakage at the valve body seals, and aging of the sealing rings is suspected. These shut-off valves are welded, and performing welding work to replace them poses risks. Is it possible to simply replace the sealing rings?
Seals of the same model can be replaced, making sure that the pressure rating matches. It cannot be disassembled if there is pressure inside the pipeline
For seal ring issues, the upper and lower sealing surfaces can be ground online. (Pressure relief status)
For pressure gauge root valves, high-pressure pipelines are equipped with two valves, while low-pressure pipelines have one root valve. Once it is confirmed that the valve can be closed tightly. The pressure gauge can be replaced. If it cannot be determined that the valve can be closed tightly, the pressure gauge cannot be replaced or repaired.
There are two valves; when the first valve was opened in the workshop, a leak was detected at the seal of that valve’s body, which is why the pressure gauge was never put into use. The question now is whether to replace the valve by performing work with an open flame, or to disassemble the valve without using a flame in order to replace the sealing ring.
If the valve is faulty and the associated pipes are depressurized and cleaned thoroughly, work can be carried out on them involving open flames or the replacement of seals. In most cases, the vehicle must be parked to carry out maintenance work.
There is a medium and pressure inside the pipeline, the first valve does not seal properly, and moreover, the medium used in the hydrogenation unit is flammable and explosive; therefore, any leakage poses a great risk, so it is not possible to replace the valve seals while the system is in operation.