Information about inches calculation

[TANKO]

Good evening, a stupid question for you...but very important for us.
So, we should calculated the inches of welding from 500 sketches dwg.
We are not specialized in piping.
We are proceeding in this way:
for example 10 joints from 10" = 100"
It is correct?We are not calculating the development of the pipe.
Thank you very much.

 

[zdas04]

I'm not sure what you mean by "we are not calculating the development of the pipe", but the weld inches is off by a factor of 3.1454 or so. The estimates that I've gotten have used nominal pipe size (10-inch not 10.75 inch OD or 10.020 ID for Sched 40) and used the circumference. So a 10-inch weld is 31.4 weld inches, 10 of them is 314 weld inches.

People that have a flat rate per weld inch generally specify a pipe schedule that that it applies to, and then they have an adder for every 0.10 inches of wall thickness over standard. I've never seen a subtractor for pipe with thinner wall than standard but it isn't impossible.

David

 

[DSB123]

tanko,
I cannot see any inconsistencies in your calculation - Yes indeed 10 joints of 10" long does equate to 100" and always has done since time began.

 

[TANKO]

Yes yes...it is correct.

Thank you very much