saddle layout

[pmmch63]

i have a small piping project involving several 90 deg. tee branches with 4 in. schedule 40 pipe. I have constructed a template with auto cad and transferred it to 1/16 in. garlock gasket mat'l. The template works great, but i was curious as to whether this technique is really practical, especially concerning the time it would take to construct a template without the aid of software. I'm certainly not a pipefitter by trade (a machinist actually), but i'm sure i've seen pipefitters at some time in the past laying out miters and such on pipe without the aid of a template. i know about dividing the circumference into 8 or more equally spaced segments and constructing lateral lines down the desired length, and then starting at a common line drawn around the diameter of the pipe, but i'm lost as to how to figure the distances to mark the lateral lines to construct a miter. i can't find any info in the two pipefitter handbooks i have or the internet. can anyone help a pipefitter wannabe?

 

[JTMcC]

You only need one pipefitting book to manually make any type of layout. The best is the "Blue Book of fitters.....welders pattern and layout manual", the second best is "The Pipe Fitters and Pipe Welders Handbook".
With both of these you have everything covered. Both show how to do what you want to do. Or, you can buy a book of ordinates that give you the numbers for everything imaginable.

Either way is an exercise in 1940's technology. Fabricating branches hasn't been practical for decades, and I don't work anywhere that will even allow a homemade branch put into service. Life is faster, easier, cheaper and simpler if you just buy fittings.

JTMcC.

 

[pmmch63]

Thanks for the info, I'll check into one of those handbooks you mentioned. Regarding fabricating branches, this is not something I would consider "in service", since it is only serving as a gaurd rail to seperate a parking lot from another area. Besides, having the skill to build rather than purchase is something to be proud of, that is, if you have time on your hands like I do. But I do appreciate knowing where you would or wouldn't work, though I found that info to be somewhat useless. Thanks again.

 

[JTMcC]

Sorry for the confusion, I'm not saying where I will or won't work, I'm saying that I've never been on a piping job where a homemade branch would be allowed, fittings are required. In case I'm still unclear, I know of no gas company, refinery or industrial plant where we would ever be allowed to install a hand made branch in pressure piping.
When you mentioned a "piping project" and "pipefitters" I was led astray.
In my work, a 12" on 12" inverted branch welding test is common, some places require layout by hand, others allow a template. I've done probably 20 or so of these test's and even with a good set of numbers you still end up with a fair amount of grinding for a really good fit.
Of course you won't need the fitup required on a test.
Hopefully you won't find any of this info "useless" <g>.

regards,
JTMcC.

 

[GenB]

JTMcC.
You are so lucky that you get this...threads...
Can you fight back? wrong forum or something..
this forum is not parking lot stuff, is it?
ER