Ask about pipe connection issues
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I encountered a problem. There is a very long safety valve discharge main pipe, about 1000m. There is no valve in the middle. The medium is flammable, explosive and corrosive (EDC, VCM, HCl). It is impossible to replace it cleanly. Now I need to change the direction of the end pipe. I don’t know how to deal with it? Please help with suggestions. This post was last edited by WSL01218 on 2009-3-31 11:58 ]
You can first close the front and rear valves of the dynamically welded pipe section, remove the pipe, purge it with nitrogen, and then proceed with the dynamic welding! ! !
If you pour water, you won’t get any points deducted! Just add the blind board and it's done.
Water injection, then mechanical cutting, prefabrication, with as little on-site welding as possible
High-level drilling, tapping, water filling, pipe modification, and plugging. Besides watering, what else can you do?
If the pressure is not high, you can use UPVC, ABS engineering plastics, etc. to connect the ends without welding.
I agree with what the people above said. We did the same thing last year when we renovated the oil depot pipelines. We filled them with water. This is the safest way.
Injecting water and then cutting mechanically is indeed a good idea, I strongly support it! ! !
When the tank is filled with water, flammable and explosive media can be driven out. Even if it cannot be completely driven out, it can still act as a water seal. The pipe at the redirected end can be prefabricated first, which can reduce the number of dangerous section welds (only one welding point).
There is a serious problem when flooding with water. There is HCl, which is troublesome!
Drill holes, saw them off by hand, add a blind plug on the inside and weld the flange on it, the other side can be prefabricated elsewhere, and finally the flange is connected.
Cut it with water and saw, use asbestos cloth to pour the liquid from the foam fire extinguisher on the end that needs to be welded to block the pipe, and then weld the flange. All other components are prefabricated and then connected to the flange.
Personally think: 1. Cut off the air inlet valve and safety valve 2. Make a hole in the pipe, insert the hose, use an air extraction device to extract the air and connect the outlet to the water. Pay attention: When opening a hole in the pipe (because I don't know what the diameter of your pipe is), you need to put water into the opening of the pipe to prevent leakage. Or install a fan nearby when opening the hole
There is HCl, what material is it made of? What is the HCl content? It is the discharge port of the safety valve. Are there really those three things in the pipe? How thick is the pipe? Can it be cut or sawed by hand? If the HCl content is not high, you can fill it with water, which is the safest, but you still need to add a blind plate.