General Calculation for Welding CS Piping

[deepsteelblue]

I'm looking to measure the shop against an industry standard for the time in take in mhs to fabricate various runs of piping that will be assembled on a skid. Is there any general calculation that will help me in doing this? I've looked at welding calculators online but they are very specific on some of the parameters required and all I need for example is just the mhs it takes to weld up 10' of 1.5", XH,CS, ASTM A106-B Smls piping, with a few tees, valves, and flanges. If I had the weld inch total, I could just take that and times my mh rate, assuming a welder could bang out 80"- 100"/day, but the calculation I see for coming up with weld inch totals is different on different sites and I know it is dependent on wall thickness and the # of passes required. I appreciate it

 

[XL83NL]

Whats mhs? Minutes hours seconds?

There's no industry Im aware of, however I havent really looked into that previously. We have created our own spreadsheet for calculating prefab piping for skid mounting/assembly. One 'standard' we found didnt fit our scope of work, as we dont fall in the typical scope (Im talking DACE's cost engineering here, a Dutch initiative).

Huub

 

[MJCronin]

Welding time for piping assembled onto a skid ???

I am afraid that no standard amount of time per weld inch will be available to you

Furthermore, more time is probably involved in piping and valve fit-up for a skid than a more customary job IMHO

MJCronin
Sr. Process Engineer

 

[KevinNZ]

There a few books/manuals you can use. e.g Estimator's Piping Man-Hour Manual

 

[Rputvin]

Our shop takt time pace is 14" of weld per hour. I have no clue where that compares to any industry standard, but that's our pace. This includes prepping the bevel, setup in a fixture or rotary table, tack weld fitting, 2-pass groove welding the pipe, and an inspection. We're building 2-12" piping skids, SA53 or A106 standard wall (sch 40), with no preheat or PWHT included in the time. Root pass is TIG, cap pass is either TIG or MIG depending, we have WPS for both. We calculate circumference of the pipe, x number of welds, x2 passes, divided by 14" to get a rough number of welding hours for budgeting. This doesn't include other pipe fitting, threaded work, assembly, placing other components, etc, just the welding.