Threading stainless pipe

[DavidMBrown]

We have installed some aboveground jet fuel piping. It is 1.5" Schedule 40 304 stainless. For larger diameters we have always welded pipe but this time we decided to thread it. Now, all the joints are leaking, some worse than others.

Is there any reason not to be threading this pipe? Is stainless resistant to threading for some reason? If so, we would either replace all the pipe with welded, or perhaps simply weld the pipes to the fittings.

Or is it probably just operator error? Our supervisor thinks he may have simply not made the threads deep enough. Then we could recut all the threads and try again.

 

[CoryPad]

What thread type? Any pipe dope or thread sealant?

Regards,

Cory

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.

 

[DavidMBrown]

NPT threads. Gasoila pipe dope (fuel resistant).

 

[NickE]

NPT threads leak no matter what you do about it.

or so I've always been told

 

[MikeHalloran]

Buy a thread gage, use it, and try again.



Mike Halloran
Pembroke Pines, FL, USA