If there is internal leakage in the valve and the pipeline at the rear needs to be welded, what should be done?
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This post was last edited by *banya2009 on 2017-10-12 11:03. What to do if there is internal leakage in the valve and the pipes downstream need to be welded? That’s right; the cooling coil of the sampler is severely corroded and needs to be replaced. The inlet pipe is a 1’ pipe; there are two valves in front of it. The first valve cannot be closed as its nut is damaged, and the second valve has internal leakage. Between the first and second valves, there is a flange with upper bolts. 1. The first method: Initially, the plan was to close the first valve, then remove the bolts of the intermediate flange, take off the rear cooling coil, and weld it again. But since it’s now impossible to close the first valve, this approach has to be abandoned. 2. Second method: After closing the second valve, there was an internal leak. We wanted to use a saw to cut away the cooling coil at the back end for sampling, but the internal leak analysis came back as unsatisfactory; the safety officer wouldn’t allow welding to be carried out. So how can it be welded back in?
Find a way behind the second valve to remove the flange.
It’s not clear what material it is; try to replace it from the front end, rinse it with water, and then remove the flange.
Doesn’t the valve come with a flange already? If the valve does have a flange, then the pipeline behind the second valve can be removed. A blind cover is added for internal leakage at the second flange.
Temporarily installing a blind flange is probably the only solution.
This post was last edited by *banya2009 on 2017-10-12 at 15:10. It is reiterated here that the diagram shows that both valves are welded valves. If the flange bolts in the middle are forced to be removed and gas leaks, how can a safety blind plate be ensured? Since the first valve could not be closed properly and the second valve was leaking, gas was already escaping from the corroded sampling coil; therefore, it needed to be addressed rather than seeking another sampling point. Please continue the discussion.
I just don’t know what gas it is or what the pressure is The only solution is to add a blind plate in the middle and then saw off the valve that is leaking internally----
We need to find a way to close the first valve and install a blind flange; is the valve unable to be closed or what?