Number of welds to make pipe from plate. 2

[1THN1]

Our sub-supplier are making a 52" pipe for us of ASTM A516 material. Do anybody know if there are any restrictions on the number of longitudinal welds to make such a pipe?

Do you know if this is written in ASME B31.3?

Any help is appreciated

 

[metengr]

5471
Do you mean weld passes per seam or number of seams?

 

[stanweld]

Because the skelp (plate) width is > 13.6 ft, many mills would have to make the pipe with 2 long seams if 40 ft lengths are desired.

 

[1THN1]

Hello metengr.

I was thinking about how many longitudinal seams to weld the pipe together from ASTM A516 plate is allowed according to code.

The Outer diameter is 52" and the thickness is 50 mm.

Best regards,


Torgeir

http://www.propure.com

 

[stanweld]

B31.3 does not address. The ASTM or API materials specification does. Review A-672 and API 5L.

 

[1THN1]

Stanweld,

Thank you for your reply.

The ASTM A672 handles the electric fusion welded pipes.
Are there a standard for saw (sub arc welding)released from ASTM?

Regards,

Torgeir

 

[SJones]

Yes - A671 and A672. Submerged arc welding is an electric fusion welding process with filler metal. The ASTM terminology is archaic and confusing.

Steve Jones
Materials & Corrosion Engineer

http://www.pdo.co.om/pdoweb/

 

[1THN1]

SJones,

Thanks a lot for your helpful reply.

Best regards,

Torgeir

 

[1THN1]

SJones,

I have bought and read throug ASTM A672.
The standard does not say anything about number of seams/plates to form a pipe.

Is it then resonable to say it is allowed, since it according to the standard is not disallowed to form a pipe from two plate segments?

Best regards,
Torgeir

 

[vesselfab]

Rolled plate and welded pipes are normally fabricated in 10-12 ft long sections (sometimes longer) and then welded together to make 36-48-60 foot long pipes. so a pipe may be built in several plates.

I hope your fabricator is planning on forming each section in 360 degree portion and not two (2) 180 degree portions.

 

[unclesyd]

Does your fabricator have a source of plate long enough for a full circle or are you talking about adding a short piece to a 12' plate to roll the 52" dia?

 

[SJones]

ASTM A530 and/or ASME B36.10 may dictate the number of seams that are allowed and should be reviewed for confirmation.

Steve Jones
Materials & Corrosion Engineer

http://www.pdo.co.om/pdoweb/

 

[stanweld]

For making large bore pipe, pipe mills will either make it with two long seam welds 180 degrees apart (for very large diameter pipe, three seams 120 degrees apart may be required) or with single long seam about 10 to 12 ft long as stated by vesselfab. The short sections can then be made into longer pipe lengths by the mill by circumferential butt welding sections together (refer to 11.3 of A-671 & A-672).