WPS review

[engr2GW]

Good morning all,

Here is the essentials and other variables for welding an API 15k 4130 flange/material to an A 106 grade B line piping or other P1 line piping. I've had mixed opinions about the use of FCAW for pressure piping, the ER80SNi-1, etc.

WPS is as follows:
BASE METAL: ASTM/A519 Grade 4130 Q&T API 75k material to any P1 material. thickness of 0.1875" to 1.3480"

TECHNIQUE: GTAW root and hot pass with ER80SNi-1 electrode, uphil AND FCAW fill and cap with E71T-12M electorde, uphill. no trailing shielding gas, back gouging, peening.

CONSUMABLES: EWTH-2% electrode, ER80SNi-1 consumable, E71T-12M consumable..

PRE-HEAT AND INTERPASS: 200F min. preheat, 200F-600F interpass

PWHT: 1275 hold for 1.5hr. 1hr per inch of wall thickness.....

The WPS did pass, it was written by a contractor in 1999, even though they passed, does it look like what you would recommend for a wellhead transition application to line piping?

I've heard someone say:
1. that FCAW is not recommended for pressure piping... but I think B31.3 references Section IX which inturn allows FCAW
2. that FCAW are generally used for structural and marine welding...any take on this for pressure piping???
3. they recommend ER80S-D2 TIG low allow INSTEAD of the ER80SNi-1 that was used, stating "it is used for MIG or SAW welding meets the weathering requirements of AWS D1.1 and D1.5 NOT FOR PRESSURE PIPING"

Any input will be greatly appreciated!

Thank you.

 

[jbeckhou]

Did the charpy impact testing pass? Most of the WPS's I have seen using FCAW have very low CVN results.

We use SMAW process for 4130 to a106 with 1125 +/- 25 degs F.

Petrotrim Services

http://www.petrotrim.com

 

[engr2GW]

1. There was not charpy impact test requirement, it's not a low temperature application. There was just preheat-welding-PWHT-NACE hardness survey.

2. By SMAW do you mean for the fill and cap or for the root bead and hot pass also?

3. What do you thinnk about the processes listed in the WPS posted??

Thanks jbeckhou!

 

[jbeckhou]

mysarah

What PSL level is the welding required to meet.

Root Pass, GMAW, fill and cap SMAW.

In regards to the WPS, I would make sure it meets current standards, NACE, API, etc. If your not sure about the WPS, run it again and see if the results are the same.

Petrotrim Services

http://www.petrotrim.com

 

[Duwe6]

FCAW w/o shielding gas "Inner Shield" vs gas-shileded "Dual-Shield" -- FCAW-SS vs. FCAW-G -- tends to have poor low temperature Charpy's, and is a poor choice for X-ray quality welds. Tends to leave a lot of small pieces of slag [graded as Porosity when reading the RT film].

Having said that, the [sort of] new Cincinnati Red's baseball stadium was built with the field-welds being run with FCAW-SS, self shielded. Engr demanded Bridge quality welds [slightly tougher to meet than ASME 'Full-RT'], and the Ironworkers achieved it. Since these welds were UT'd 100%, and then re-UT'd a 25% sample, the risk of slag was nil. And UT is much more forgiving than RT of fine, scattered porosity.

If you use this WPS, RT early and often until a 'level of comfort' is achieved in the quality of welds your welders are capable of.

 

[engr2GW]

Thanks everyone.

I'm ordering materials to write another WPS for this same application. and I intend to use:

1. GTAW root and hot pass
2. 7018 fill and cap
3. 350F preheat minimum (200F seems a bit low for 4130)
4. Same PWHT as above.

Does that seem like a better option? what would you change if it were you on everything generally, but on the filler metal particularly?

 

[Duwe6]

E-7018 is the 'premier' type of rode for C/S. Of the E-7018's, I and almost all X-ray class welding contractors prefer ESAB's "Atom-Arc" E-7018. In the EU and the Far-East, it has a numerical designation vs. this name. It is VERY worth the extra expense of buying it instead of whatever seems to be low-bid. Think of the cost of only one weld repair. Pays the extra cost for the cost of a LOT of premium rod.