Welding issues with PTFE-lined pipes
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Regarding the welding of PTFE-lined pipes, there are the following issues: 1. Since the pipe raw material is lined with PTFE, will this lining be damaged during the prefabrication and welding process of the pipe sections? 2. If the PTFE lining is damaged, what kind of process can be used to repair it? I’m in a hurry; I don’t have any relevant experience. Thank you all!
1. It will be damaged, 2. It cannot be repaired. 3. It is recommended to use flange connections
Thank you so much! However, the pipeline materials lined with PTFE are provided by the owner, and our company is required to pre-fabricate these materials into pipe sections. Welding is involved in the prefabrication of pipe sections – are there any good suggestions?
The PTFE-lined pipes in the finished product cannot be welded; once the lining is damaged, it cannot be repaired, and the only option is to weld them first without a lining and then apply the lining afterward
Generally, these are finished sections with flanges at both ends, or pipes without an inner lining that are welded first and then lined. I’ve never seen anything like what you described; it seems there’s no good solution for this
Consider reserving a section and then returning to the factory for re-lining; consult the manufacturer, as some can be lined on-site.
Is this a steel pipe or a fiberglass pipe?
This is a carbon steel pipe lined with PTFE
Lining is usually applied after the piping has been welded, and the length of each pipe segment is generally around 2 meters.
There is a new modified PTFE material called NEW PTFE that can be welded: lol. Daikin in Japan offers it; those who are interested can look into it. PFA can also be repaired
We specialize in steel-lined PTFE pipes. In principle, finished steel-lined PTFE pipes are not allowed to be welded again, as PTFE becomes toxic at high temperatures. If you have any further questions, feel free to contact me!