Ptfe Tape or pipe dope?

[Rob1962]

I'm doing some Plumbing tonight I'm using a reversing valve on a Regner Max should I use teflon tape or pipe dope or just plain by itself This is obviously steam line.

 

[phils2um]

I'm not involved with steam but suggest that teflon tape is your best choice. It is easily removed if need be. Just don't over do it. You do need something though.
Phil S.

 

[Rob1962]

Thanks Phil PTFE it will be.

 

[Homo Habilis]

While I do not have any experience with steam engines I often use the appropriate RectorSeal product with great success. Perhaps it will work for your application.

 

[JimmyB]

It all depends whether the seal is on a taper thread (ptfe tape) or a union (dope); as a engineer dealing with high pressure systems (6,000 psi plus) I am infuriated to see ptfe around parallel threads when the seal is on a union or olive

 

[ARIA31]

I don't know the exact word in english, but with high temperature the PTFE will not keep its properties. ( il va fluer ... in french) so getting soft.

 

[stockers]

Is that not how it works?

 

[TLR]

I don't know the exact word in english, but with high temperature the PTFE will not keep its properties. ( il va fluer ... in french) so getting soft.

While it is true PTFE will soften it is ideal for gaskets etc provided they are held in position, its' melting point is about 620 F [ 327 C ] so ideal for piston rings etc, I read a few years ago of somebody making piston valves entirely of PTFE rod and having some success.

Shaun

 

[Greg Elmassian]

I'm not an expert, but did research this since I have a pneumatic system for my turnouts, so I researched this subject... I came back with what Jimmy B says.

Greg

 

[phils2um]

Yes, I too have to agree with Jimmy B. I had just assumed tapered pipe threads when I recommended teflon tape. - Phil S.

 

[The Tinker]

I use teflon paste much more reliable