BSP plug in BSPT hole and vice versa

[tendim]

(Sorry for the cross-post, but I figured this forum might be a little more knowledgeable in my question).

I've currently got a BSPT hole that requires a T-fitting. A local retailer told me that I could use a BSP T-fitting and plug that into the BSPT hole, and then plug my already existing BSPT plugs into the BSP T-fitting. So what I would end up with is this:

(BSPT hole) <-- BSP T-Fitting <-- BSPT Plug

Directions of the arrows indicate plug -> hole.

Is there any danger in doing this? I've read some other threads that stated a BSP plug usually requires some type of face-sealant such as an O-Ring; but does the converse also hold?

Thanks for any advice,
-10d

 

[Drazen]

It is really dependant on operating conditions.

For sizes under 2 inches couplings are regularly delivered with straight tapping, but only normal schedules. Extra strong and double strong schedules as well as dimensions larger then 2" are normally delivered with tapered fittings because they are superior!

It is up to you to decide is your application really non-critical or not. Or I can help if you send data about application

 

[tendim]

Hi Drazen.

All fittings are 1/8". The original BSPT hole is in an engine block, and will be used to install a (new) oil pressure gauge. My only concerns are with heat and oil pressure from the engine.

When you say "2 inches" I assume you are talking about the diameter of the hole? Or the length of the plug as plugged into the hole?

 

[MikeHalloran]

I'd call my Swagelok dealer and order the correct fitting.



Mike Halloran
NOT speaking for
DeAngelo Marine Exhaust Inc.
Ft. Lauderdale, FL, USA

 

[Drazen]

Yes, 2" refers to diameter.

Well, engine demands have a little different determination.

I think that you could have leakage problem if you use proposed fitting, but you can simply test it, for that diameter, there couldn,t be so big leakage to endanger your engine if you freqeuntly check in initial period.

But temperature issue shouldn't be practically tested, you have to be sure before assembling!
Temperature matter is really not related to thread, but to material of the fitting. You should know temperature conditions, that can be big issue with engines, and then check it with your fitting seller. I don't beleive that ordinary metal-shop fitting can have engine temperature rating.