I have been tasked in developing a WPS for my company, but I am having a little trouble. I need to be able to write a procedure that supports welding 2" 304 Schedule 5 and 10 pipe used at temp -240F and 250 psi max. I am using ASME B31.3 for production which tells me to use ASME IX to certify procedures and welders. Here are my specific questions:
1. I am unsure of the demensions/tolerances to use for the joint design for open root using the GTAW process, I can find prequalified CJP groove joints such as B-L2b on page 40 of D1.6 but that is a structural code so where can I find a joint design that will be acceptable?
2. QB-402 Base Metal. If the base metal for schedule 5 pipe is .065 according to ASME IX table QW-451.2 the range of thickness qualified is T(Min.) to 2T (Max), but note 1 says see QW-403.2 which states that "The maximum thickness qualified is the thickness of the test coupon. Which do I follow?
3. QB-403 Filler metal. I read the ASME IX table QW-451.2. is says the thickness t of deposited weld metal qualified is 2t max. How do I figure out the thickness of weld metal to put on the WPS, is it the thickness of the test coupon plus the allowable reinforcement?
I am new to the ASME codes and it seems there are not as informative as the AWS codes. I would greatly appreciate any assistance. Thanks
Once you become acquainted with the ASME Section IX code, I think you will find it just as easy or easier than AWS codes to decipher. It has been around longer than most AWS codes, and has been refined and interpreted to clarify almost any situation. Regarding your specific inquiries:
1. ASME Section IX does not define any joint dimensions. Joint dimensions must be addressed on the WPS since they are non-essential variables, but they are up to the end user. Some ASME codes do have some typical configurations, such as B31.3 figure 328.4.2. If you want some more guidance as to recommended practices on open root joints, (I haven't had the opportunity to peruse them myself), but perhaps recommended practices or prequalified welding procedures available from AWS might be able to help you.
2&3. Note that the table you are referencing is for longitudinal bend tests. I don't believe that table would be applicable to 2" pipe. What you need to do is read section 2 in it's entirety (section 1 would help as well). It is the primary section for procedure qualification. You will find your essential variables in table QW-256 for the GTAW process. You also reference QB-402 and QB-403. Those are for brazing, not welding.
Dude, from reading your questions, you've got a plate full. Easy stuff, but not for one with limited experience in ASME.
At the temperature mentioned you will probably have impacts also.
ASME IX is modified by ASME B31.3 so your thicknesses are governed by B31.3 and more specifically, the thickness for impact qualification which B31.3 sets at 1/2T to T + 1/4" where T is the thickness of your test coupon.
Another small thing (typo?) QB governs brazing, you want to make sure your checking QW Sections.
Looking at the thickness mentioned, I am "assuming" your using GTAW process?
Joint designs can be garnished from B31.3, in general you will only have a high-low fit-up tolerance for the thickness your using. Groove design isn't an essential variable in most cases however the most common bevel angle in pipe applications is 37.5 degrees, 75 degree included angle.
Your tests will include tensiles, bends and probably impacts.
QW -400 covers variables for procedure qualification. Not every variable is applicable to every process. Not sure what process you are using,( I too would think it to be GTAW) but of the welding processes that QW-252 covers, QW-403.2 is only applicable to oxyfuel welding.(which I highly doubt you are using.)
Correct and if impacts are required, as I assume they would be with the temperatures mentioned, the Supplementary Essential Variables would also apply, as modified by B31.3.
jon is right. It looks like impacts. And I would suggest getting some help if you're new to ASME. B31.3 (like its mother Section VIII) for impacts is complicated and can be a nightmare for the uninitiated.
By 3.1 Inspector
Date 07-09-2008 18:40
Hmmm, I am pretty sure that you can go well below -250 F without impact for that particular grade of steel.
Table 323.2.2
Austenitic Stainless Steels
Column A Design Minimum Temperature at or Above Min. Temp. in Table A-1 or Fig 323.2.2A
Section A-4 (b)Weld metal deposits shall be impact tested per para. 323.3 if design min. temp < -20degF, except as provided (in notes)
See what I mean?
jeff
Or,
323.2.2(f)(2) For austenitic weld metals having a carbon content not exceeding 0.10%, and produced with filler metals conforming to AWS etc., etc., at design minimum temeperatures of -150degF and higher; or having a carbon content exceeding 0.10% and produce with filler metals conforming to AWS etc., etc., at design minimum temperatures of -55degF and higher.
It just keeps gettin better.
Jeff,
I understand after reading all the notes and tables in B31.3 that impact testing is required for piping with a temp lower - 150 deg f. Is this test just required for WPS qualification or is it also required for production? Thanks.
Chris
Should be necessary only in qualifying the WPS to be used in production.
jon is right, as usual.
It is only requred for for WPS quals (Table 323.3.1 makes it clear in A-5 (b) that heat/lot impact testing is not required unless by engineering design). But, if you use materials not impact tested by the manufacturer you will need to have independent impact testing of the filler metals.
By 3.1 Inspector
Date 07-09-2008 19:38
Edited 07-09-2008 19:42
meeeh...
I wrote some crap - its late and I am tired :)
Sorry if I caused confusion!
3.1
31.3 is tough. And unless you have been a committee member since piping was made of lodgepole pines you can't keep all that stuff in your head. I am constantly thumbing through it to refresh my memory. Which is not getting any better these days.
By 3.1 Inspector
Date 07-09-2008 20:13
Indeed!
You are right, impact is required.....I just remembered 304 to be extremely ductile and tough so why bother with impact test :=)
In a way I do like the ASME and API codes, but why is there SO MANY notes and complicating writing in it?
You HAVE to do that, that and this, but if you dont its ok to do it in another way.... hehe
The piping system I am writing the procedure for is rated at minus 240 deg F at 150 psi, I incorrectly stated the wrong pressure in my previous post. Is impact testing required I thought that was only for high pressure piping in chapter IX of B31.3.
Sorry for the confusion I was looking at QW vice QB and I am using the GTAW process.
By 3.1 Inspector
Date 07-09-2008 19:19
I will try to answer your questions - please take note that I am NOT American (as stated in a post some time ago :O) however I do have some(minor) knowledge about ASME
1. Everything in regards to joint design is a nonessential according to section IX(QW 256 for GTAW), which means that you can write what you want - within SEP tolerance.
2. Look at table QW-451.1 second row - 1/16 to 3/8 (I think schedule 5 and 10 is within that range) you will see that your qualified thickness is from 1/16 to 2t. You will also see which kind of mechanical tests is needed (2 tension, 2 face and 2 root)
QW 403.2 is not applicable for GTAW(Look at QW 256) but is applicable for OFW(Look at QW 252)
3. No, the deposited weld metal is without reinforcement - you will se it follow the material thickness until you work with thicker material.
Hope this will help you...or atleast I will be corrected and the right answers will come :)
3.1
3.1
Have you gotten your test results yet?
By 3.1 Inspector
Date 07-09-2008 20:45
no, you?
No not yet....on the website it says not to call until the 23rd or 24th and I dont want to piss them off by calling. How long does it take to grade a multiple choice test??
All thanks for you insight, I am starting to see the light.
3.1 Inspector; I reiterate you CANNOT use the 2T rule for ASME IX since B31.3 permits a maximum of T + 1/4" for impacts and a minimum of 1/2 T. Trust me on this one, I have a change of rules request in with the B31.3 Committee to permit certain exemptions for austenitic and nickel materials; neither of which are exempted from impacts (even in the base code section). Chapter IX of B31.3 begins at pressures EXCEEDING 10,000 PSI so clearly this doesn't apply in this case, regardless, impacts are most likely required.
Important Note: For those with lesser ASME experience; ASME IX is NOT a stand-alone code... nothing is welded in accordance with ASME IX except for performance and procedure qualifications. For fabrication or construction, ASME IX is ALWAYS secondary to the constructing code, i.e., B31.3, ASME VIII, etc., that's one reason so many people get confused using ASME Code.
By 3.1 Inspector
Date 07-10-2008 13:51
I posted before I found out impact was required, I am very well aware of it.
Thank you.
By 3.1 Inspector
Date 07-10-2008 13:56
Important Note: For those with lesser ASME experience; ASME IX is NOT a stand-alone code... nothing is welded in accordance with ASME IX except for performance and procedure qualifications. For fabrication or construction, ASME IX is ALWAYS secondary to the constructing code, i.e., B31.3, ASME VIII, etc., that's one reason so many people get confused using ASME Code.
:=)
Jon,
Can you tell me where you found B31.3 permits a maximum of T + 1/4" for impacts and a minimum of 1/2T. I would greatly appreciate it.
Thanks,
Chris
Chris,
Table 323.3.1 A-5 (a)
Regards,
Shane
Shane,
Let me see if I get this right if I weld a 2" stainless steel pipe with a wall thickness of 1n 1/8" my procedure would be qualified in the thickness range of 1/16" to 3/8". Does that rule only pertain to procedure qualification or does is also pertain to performance qualification? Thanks for your help.
Chris
Chris, that would only be for Procedure Qualification.
Hi Jon,
Need a bit of advice from you and js55 please.
Hypothetically I test a 15 mm basic carbon steel plate to ASME IX and I perform impact tests.
Based on QW 451.1 my BM qualification thickness is 5 mm to 30 mm
Based on QW 403.6 my BM qualification thickness range is 15 to 30 mm
Based on B31.3 Table 323.3.1 my BM qualification thickness is 7.5 mm to 21.4 mm.
How do I document the BM thickness on my WPS ?
Do I need a different WPS for each scenario above ?
Do B31.1 and ASME VIII (for example) have even different qualification thickness ranges ?
Haven't had a lot of exposure to impact testing so any advice is greatly appreciated,
Thanks and regards,
Shane
Shane,
It really depends on how you want to handle it.
No you don't have to have different WPS's(though some customers might say otherwise). And B31.3 is of course much more stringent that Section IX when it comes to impacts. 31.3/VIII, etc., take precedents.
I generally use a page 2 to seperate out thicknesses. Others find seperate WPS's more to their liking. I use single WPS's for as welded and PWHT so I run into similar situations all the time depending upon the PQR's available (for example I may be able to go to 8" thickness on PWHT stuff and maybe only 1 1/2" on as welded-not uncommon).
In your case I would use a page 2 to break down the WPS for different applications, say non CVN stuff, CVN stuff per 31.3 etc. But at some point you may think its too complicated.
Most of the complication actually is while in process because as time goes on I try and increase the thickness ranges allowed and the differences go away.
Jon may do it different. I don't think any way is better than others but some may be better for you.
The different qual thicknesses are related to impact testing of which 31.1 doesn't have any. Its strickly Section IX. The graphs of 31.3 were born from Section VIII so they are quite close. I think you'll find that most of the confusion is based upon whether or not you have to do CVN's and where the specimen needs to be. If you've done them the thickness ranges are quite close.
Hope this helps.
js55,
Thank you for your response, greatly appreciated,
Regards,
Shane
