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Up Topic Welding Industry / General Welding Discussion / Steam and Condensate Lines
- - By cocoloco Date 04-06-2006 16:07
How does E6010 (SMAW process) followed by E7018 sound for welding schedule 40 ASTM A53, Grade B pipe?
Parent - - By welder5354 (**) Date 04-06-2006 16:51
No Problem, that is your typical setup f3/f4 using A53, Gr. B or A106 , which is seamless pipe and a little more expensive.
Parent - - By Shane Feder (****) Date 04-06-2006 23:55
Cocoloco,
It would pay to check your specifications / contract documents.
I personally think you would be better off with GTAW root run for steam piping.
Does anyone know if B31.1 has anything in the code regarding the use of cellulose electrodes ?,
Regards,
Shane
Parent - - By pipewelder_1999 (****) Date 04-07-2006 01:34
Its a common process and is not restricted by B31.1 . I actually prefer it over GTAW usually. In my opinion with SMAW 6010 you can tell alot more when it going in good . The sound, the sparks, the keyhole. MMMMM ! I love it .
Parent - - By pipehead (***) Date 04-07-2006 01:59
The standard 5p root and hot pass and low hy out is great but I have to agree with shane That most of the steam piping I have worked with was GTAW root. with a low Hy filler and cap
Parent - By pipewelder_1999 (****) Date 04-07-2006 13:40
I think you are probably correct. Most of mine is the same but as a welder I prefer SMAW and the code does not restrict it. Many company piping specification do have process limitations based on service, initial cleaning prior to startup etc.

The project specifications would be the place to look for these types of prohibitions, not B31.1 .
Parent - - By chall (***) Date 04-07-2006 13:54
Schedule 40 pipe seems kind of lean for a steam application.

If you don't mind, what is the pressure, and is it superheated or saturated? What is the pipe diameter?

Charles.
Parent - - By cocoloco Date 04-08-2006 06:17
It is a low pressure system; 350 psig, saturated steam. I truly appreciate all the input. Pipe diameter varies from 10" maximum.
Parent - - By welderette (**) Date 04-08-2006 14:06
What is the Steam Temperature?
Parent - By supermechanic (**) Date 04-08-2006 22:46
Temperature of 350psi sat. steam is appx. 437 degrees f.
Parent - - By chall (***) Date 04-11-2006 12:36
If you look at B31.1, Table A-1, you will see that only seamless A53-B pipe is allowed.

Using section 104.1.2 and solving for minimum wall thickness the following are so:

S = 15,000 (up to 650F, from Table A-1)
E = 1
y = 0.4
P = 350
D = I did it for 2", 6" and 10" pipe
A = corrosion allowance. We normally see 1/16" (0.062")

t for 2" = 0.089"
t for 6" = 0.139"
t for 10" = 0.187"

It looks like sch 40 is OK; I've just never seen anything below sch 80 used in steam lines.

Please check my math before relying on the numbers posted.
Charles

Parent - - By MNSTRBLDR (**) Date 04-13-2006 20:33
We 5P roots on steam lines except final steam to a turbine or something. We also tig rooted our new 48" main header from the new co-gen plant. 7018 the rest, hope this helps
Parent - - By medicinehawk (**) Date 04-14-2006 22:10
What ever process used to weld steam or condensate pipe lines is determined by the specifications of a given job. We know ASME allows either Tig roots or 6010 roots. What is more cost effective????? I guess you might agree smaw is, BUT................what does the Client want???
I have been on some jobs where they Tig & hotpass steam/condensate, but I have also been on a majority of jobs where 6010/7018 is how we do it.
IT really depends on how the job is bid, what criterion is used for QA/QC purposes AND who is paying the Bills for the project.
I would rather Tig a root because I think it is easier & being that 70-S wire would be used......technically that weld is stronger as the tensile strength is higher than with 6010.
My 2 cents.
Hawk
Parent - By Bill M (***) Date 04-17-2006 15:54
Just another comment:
The ASTM 53 Grade B pipe minimum tensile is 60ksi ...so the 60ksi root weld metal is not under the tensile of the base metal.
Up Topic Welding Industry / General Welding Discussion / Steam and Condensate Lines

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