When using threaded connections, sealing welding is sometimes employed for welding – what does this mean?
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When using threaded connections, sealing welding is sometimes employed for welding – what does this mean? Was a weld applied around the joint after the threaded connection was made?
This post was last edited by ylb913 on 2016-7-6 at 20:03. This has been a standard practice for many years now; a seal weld is used in front of the first threaded valve, as this is safer. There is also a saying that if there is internal leakage in the valve, an additional valve can be installed temporarily using a double-threaded connection. Screw-threaded valves should be cheaper than flanged valves, at least as they eliminate the need for gaskets and bolts. It is also convenient to add a plug to such valves, or to use a pipe cap with dual threads. It should be noted, however, that for the plant we built in 2011 using the EPC approach, all the DN20 vent valves in the valve assemblies were flanged valves. The EPC approach includes design, construction, and procurement; by doing this, it is certainly a cost-effective way, or at least an option whose impact on economic interests can be ignored.
A plug is installed behind the threaded valve, and then seal welding is applied; isn’t it difficult to remove the threads? Valves are troublesome when in use