PTFE NPT Plugs - Are they ideal? 1

[RDelaCourt513]

I have been working on a design that features a fluid manifold made from A standard grade PTFE (temp increase up to 200C). my intention was to use a plug (which will act effectivly as a blacking plug) as I need to seal off the area. To keep expansion rates the same, i was going to use to same grade ptfe for this NPT plug, but I have been told that making a PTF NPT plug is not advised. My inital thought is that generally speaking, PTFE ha a relativly low abrasion rating. woudl this be the case, or is it someting else?

Can anyone explain to me why this is?

Thank you

 

[BrianE22]

I know it's not much of an engineering response, McMaster sells them so others must be using them:

https://www.mcmaster.com/pipe-plugs/material~plastic/material~ptfe-plastic/gender~male/

 

[EdStainless]

Just remember how much PTFE will creep, especially at 200C.
So watch how much load on these.

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P.E. Metallurgy, consulting work welcomed

 

[XL83NL]

In making the threads the seal, something’s gotta give. Normally that Teflon pipe thread sealant. With a PTFE plug you’ll either (locally) plastically deform the male or female NPT part. Not sure if that’s a good thing.

Huub
- You never get what you expect, you only get what you inspect.