Tapping 3/4 into 1" pipe

[L17Aurora]

as anyone tapped a 1" SCH 80 stainless tube with 3/4"BSP. Looking at the sizes I reckon you would lose 8% of the thread depth. I suppose what I'm really asking is what pressure would this hold before the end fitting blew out?
Cheers
Mickb

 

[GOBLINTECHNIC]

I'm not sure but I think if you want to know the actually value of pressure you can do the hydrostatic test.

 

[racookpe1978]

Doesn't seem particularly wise to "tap" into a one pipe with a branch (the second pipe) proportionally so large.

Use a 1x1x3/4 tee.

Compare the cost of the (very small!) 1 inch/25 mm pipe fitting to the loss of the pipe, the accident costs, loss of product, and (probable) liability to the design and construction company if any one is injured due the blow out of the branch.

 

[btrueblood]

racooke,

I think the OP is speaking of tapping 3/4 BSPP into the i.d. of a 1" pipe, not from the side. I.e. a step-down adapter, if you will, and not a tee branch.

 

[racookpe1978]

OK. So why not use a proper reducer with proper (100%)threads? Simple, cheap, economical, able to carry recognized loads under vibration and operational limts. Not a stiff hand-threaded shade-tree solution between dissimilar (?) metals with poor thread engagement.

You could use electrical conduit too if all you want to do is carry low-pressure fluid.

 

[BigInch]

Some folks just don't have a conventional bone in their body.

**********************
"Pumping accounts for 20% of the world’s energy used by electric motors and 25-50% of the total electrical energy usage in certain industrial facilities."-DOE statistic (Note: Make that 99% for pipeline companies)

http://virtualpipeline.spaces.live.com/

 

[btrueblood]

"So why not use a proper reducer with proper (100%)threads?"

Beats me.

 

[dvd]

My recollection of "merchant couplings" is that they are tapped pipe from next size up. Anybody know if merchant couplings are made from pipe?

 

[L17Aurora]

Thanks Guys. As you know, a 1" pipe is usually screwed 1" BSP (UK region) on the outside. I wanted to tap the bore of a "ready bored" tube. Thanks for the replies.