Calculate Welding Time ? 1

[Gregorydas]

I am an estimation engineer. I want to know an average time required for the welding (Medium Skilled Welder) Carbon Steel & Stainless steel plates for pressure vessels. For. Eg Say 10mm Thick Plate, how much time will be required to weld 1 meter of double v joint (3 pass).

Is there a formula or an excel sheet for calculating such timimgs??
Also if any of you have an easy method to calculate the weld metal deposit and welding gas (Oxygen, Acetylene and argon) consumption.??

Please help..
Thank you
gregorydas

 

[weldstan]

Depends on the welding process used.

 

[BUGGAR]

Remember to include prep time in your welding speed rate.

Many a good welder is hobbled by low paid fitter/helpers.

 

[Guest102023]

Impossible to say, but do not go solely by deposit rates, but look at the overall production over 8 hours, considering all the pertinent operations.

"If you don't have time to do the job right the first time, when are you going to find time to repair it?"

 

[Gregorydas]

Thank you all..

 

[racookpe1978]

Walk in the shop.
Pick six welders: two above average, two average, two "normal" (Think of how smart and how motivated the average person actually is. Then realize 50% of all people are less motives and are less capable and less skilled than "average" ...)
Measure their performance over several days and in several positions and degree of difficulty in YOUR shop and using YOUR equipment. DO NOT GUESS FROM INTERNET DATA FROM UNKNOWN AUTHORITIES.

 

[Gregorydas]

Thank you very much mr. racookpe1978. That inspired me a lot. Thanks

 

[Guest102023]

Be aware of the observer effect when monitoring workmen.


"If you don't have time to do the job right the first time, when are you going to find time to repair it?"

 

[berkshire]

Brimstoner,
That can have two effects depending on what the welders think they are being monitored for. If welders are paid on a production basis, they tend to slow down, so that they can get more time/money for the next job issued . If they think it is for a pending layoff, they "know" the slowest guys get let go first, so the tendency is to speed up. Either one skews the results, It is better to monitor without being observed.
B.E.

You are judged not by what you know, but by what you can do.

 

[tarekdata]

To calculate the welding cost , you need to consider the below elements.

Manpower cost

1- Welder " Craft Cost " , It is pertinent with his productivity and salary " Paid to emp. and fringe benefits "
2- Overhead cost : Supervision and management.

Material Cost
1- Welding machine depreciation or rent.
2- Consumables " wire brush, grinding disc....etc".
3- Welding electrode cost ,it is pertinent with welding bevel profile . to compute the metal volume, you need to define the area and perimeter of pipe, then Volume of metal deposit will come through math, all waste sources shall be considered through that formula.

Equipment Cost

1- electricity cost " either by Power meter or Diesel cost + operation cost of Genset ". you need to search for KW need per Kg of metal deposit , and add an allowance for idle operation. KG of metal deposit should be calculated after knowing the welding bevel profile , welding procedure, No of joint and Dia of each joint.


it is not an simple estimation job, but once you made it, you can use it for ever with little amendment and improvement. finally you will reap what you has seed.

 

[Gregorydas]

Thank you very much for the info sir. It really helped.

Can you please explain the formula for the weld deposit?

If we know the thickness, welding length, bevel depth, can we find the deposit and the number of electrodes to be used??

 

[kingnero]

weld deposit = cross section of the weld prep x length.

volume of filler material = cross section of the rod x 80% of length of the rod (to account for stub loss - check for your mileage) x n (with n = number of rods)

derive "n" .

 

[racookpe1978]

Theoretically. For "close enough" values of "n" ... 8<)

Then, what "safety margin" do you order against?
How quick, how easy is it to get more rods?
Are you working only one shift, 5 days a week, so running off to the nearest supply store is easy and cheap? Order less.
If you are working 7 x 24 on 2 or 3 shifts in the middle of nowhere trying to keep mid-shift from running out of rods on a weekend night shift ... Order more.

If you are trying to figure out weight and moment (CG) of the weld shape, (1) make sure you are ALSO figuring out the weight of the ground-out weld prep metal from the original, its weight and moment (CG) then (2) re-add back in the new metal and its final ground-off contour.

 

[kingnero]

True, but as these are quite basis questions, he gets a basic answer. Come'on now, do we really have to answer „how to find the number of rods needed" ? To get a ballpark number, all you need is basic geometry. And then you order per 50 lbs.