Welding joint

[salgu]

How much time require to weld 18" Pipe and 34 mm thickneess

 

[Dhurjati Sen]

If you want a quick job, start with two welders welding from diametrically opposite side.

DHURJATI SEN

 

[1503-44]

Correction: This uses downhill welding rates. Thickness requires uphill rates. See later posts.

5.67 man_hrs

From
34mm/3.5 mm/pass = 10 passes
Maybe 3mm-5mm/pass

Circumference
18" x 3.14 = 56 in/pass

560 inches weld / (120 in of weld per hr) = 4.67 hrs
Usually 100 to 140in weld/hr

20% other work = 1 hr

Change your variables to suit your weld procedure and productivity info.

 

[dik]

great post... didn't know that was ever done... thanks 1503

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

 

[XL83NL]

Thats an 80+%-rate, BI. What process are you implying with such a high rate?

Huub
- You never get what you expect, you only get what you inspect.

 

[1503-44]

When you're looking at 1500 km of pipeline (120,000 joints), you gotta know how to estimate welding time. Its obvious why we like high strength, [pre][/pre]thin wall pipe. Welding rate drives pipeline construction time.

Every welder on the internet says that they can do 80in/hr with one hand tied behind their back.

100 in/hr for thin wall pipe, 140 for thick wall has been stated in "Pipeline Rules of Thumb" E.W. McAllister since the FIRST Edition 1978

 

[dik]

That works out to a length of pipe being 12.5m... is that correct?

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

 

[1503-44]

I used an average 40ft "double joint" length and rounded up a bit.
Pass thickness varies by rod diameter, weld technique and groove angle(s).
Considering XL83NL question, I might have been too fast choosing 3.5mm, being too liberal for the bevel geometry for this rather thick pipe. This weld will be pretty wide at the outside surface. It should have a compound bevel, reducing the OD width, but avg pass thickness may turn out to be even less. 3.5mm works OK for estimating pipelines, usually having thinner walls, in the 5-10mm range.

So let's take a closer look.
Adjusting for weld groove angle on each pipe end, typ plain 30° bevels, or compound bevels,

This "single bevel" chart says that my number of passes estimate of 10, only works for 2x30° bevels when wall thickness is around 0.5" (12mm) or less. Hence XL83NL's concern. For the 33mm (1-3/8") thickness and estimating for a compound bevel,.. could be 15x2 =30 passes ?? Can it be 15hrs? XL83NL, is that what you were thinking.

 

[1503-44]

Found this diagram that includes welding pass patterns for thicker pipe welds.

 

[1503-44]

This one for thin wall welding, but at different positions.

 

[1503-44]

Thick wall

https://external-content.duckduckgo...id=OIP.egU-hc_kBZucVcIeeNpWHQHaLN&pid=Api&f=1

 

[DekDee]

The comments all seem to be focused towards pipeline welding which is vertical down and very fast.
34 mm thick pipe would more than likely be refinery piping and will be vertical up and much slower.
Apples and oranges ?

 

[1503-44]

After some internet research, with not a lot of published actual welding rate info there, what I have surmised is that downhill welding rates are for materials <= 1/2" or so and are in the 100 to 140 in/hr range. Uphill welding, typically used for thicknesses >1/2" 12mm, is going to be more like 80"/hr.

The OP's weld is going to take a long time.