SA778 is not referenced in QW422 of Section IX. If I qualified a welder (performance) on SA312, can he weld SA778 too? What about the procedure qualification? It a PQR/WPS was made with SA312, where does the SA778 come into play?
I just looked through Section IIA and can not find SA778. Do you mean A778? What grade?
If you meant A778, there is a good possibility that you can cross reference the UNS number of the material and find a match in section IX.
The pipe has "ASTM A778" and "ASME SA778" printed on it. I'll call the vendor and ask about the UNS number
If you tell us the grade, I can cross reference the UNS for you.
Truthfully, I am more curious about the "ASME SA778" marked on the pipe. My ASME code book doesn't contain it. The ASTM specification does not have the standard note referring you to the appropriate ASME code for bolier & pressure vessle applications. I suspect the mark is not valid.
More info:
The scope contained in A778 is interesting. It talks about the fact that minimal testing & examination is performed on the manufactured product. It's a fair bet that this is why it doesn't meet ASME requirements. Furthermore, it recommends you select A312, A358 or A409 if you need material that is heat treated or RT examined.
no luck yet on the UNS number. From what I gather, the 778 is popular in paper mills or other low to moderate heat applications below 800 degrees F.
What grade of A778 do you have?
Florida Snook,
AISI type 304L stainless steel is covered by Grade A-778L, and not by Grade A-778, as you indicate.
Fernanda Cristina da Silva
A778 Grade 304L has UNS designation S30403, which is P8, group 1 in ASME Section IX, QW422.
As far as compliance with weldability (for the PQR/WPS and welder) goes, you are set (ignoring the material marking inconsistencies).
As a couple of responses have attempted to convey, there is a problem with the material markings. If the manufacturer is improperly indicating that the material is SA778 (no such material currently approved by ASME), the rest of the markings are suspect.
If the spec requires the use of A778-304L, it is probably not a job governed by ASME. If you are still required to provide a WPS & welder in compliance with ASME Section IX, you meet the requirements.
If it was me, I would get in touch with the manufacturer, point out the discrepancies and go from there.
Charles Hall
Actually ASTM A778 Grade 304L of UNS designation S30403 does not have a P-number and is not listed in QW422. Following the rules of QW420.2, this material could be considered S-number 8, Group no. 1. ASME SA-312 has P-no. 8 and its grade determines the Group number ranging from 1 through 4. See http://pnumbers.com for a quick way to list all SA-312 materials of QW422.
A welder tested on any SA-312 grade is qualified to weld any S8 material so you are OK here. A WPS for welding any S8 material can be qualified with PQR using any SA-312 grade, except when impact testing is required.
In the unlikely event that your contract requires welding procedures qualified with impacts, then QW-403.5 supplementary essential variable applies and you would have to pay close attention to your grade of material used during the WPS qualification test. Assuming you used SA-312 TP304 or TP304L in your PQR you'd be OK. However, if you've used TP310S, TP310H or any other grade assigned to Group No's 2, 3 or 4, requalification would be required.
Art Rivera
Quite right Art. Thanks for setting me straight.
Charles
There`s no single UNS number related to A-778 steel.
Standard ASTM A-778 "Specification for Welded, Unannealed Austenitic Stainless Steel for Tubular Products" covers several grades of stainless steels equivalent to AISI types 316L, 321 and 347.
UNS equivalent numbers are the following:
316L: UNS S31603
321: UNS S32100
347: UNS S34700
Fernanda Cristina da Silva
Materials Engineering Dept.
Mackenzie University
Sao Paulo - Brazil
There is no SA778 material specification. The "SA" designation is used for materials approved by ASME for use on boilers, pressure vessels and piping. I've searched the latest edition of Section II Part A printed copy, electronic copies and IHS website indexes and can find no listing for SA778. Unless there is a code item in progress to permit its use, such as a Code Case or revision to Section II, it's not approved for use in the Boiler & Pressure Vessel Code. It sounds like the "ASME SA778" markings should not be on this material, as it is misleading at best. Can you find out who the manufacturer is?
By ArtR
Date 04-26-2003 01:19
There is no ASME SA-778. However, it appears that at least one Korean supplier thinks that for every ASTM specification there is an ASME equivalent. See http://www.e-pipe.co.kr/eng/ASTM/A778.htm for details.
After having read all of these interesting postings and having thumbed into ASTM A 778 standard, what I have to say is the following:
1. ASTM A 778 covers five different types:
TP 304L - UNS 30403
TP 316L - UNS 31603
TP 317L - UNS 31703
TP 321 - UNS 32100
TP 347 - UNS 34700
2. As ArtR points out correctly, there's no ASME equivalent to ASTM A 778, which doesn't mean at all that A 778 isn't a good quality material; simply, ASME hasn't considered it necessary to include A 778 within ASME specifications listed on Section II. Why? Perhaps because stainless steel tubing, after all, isn't largely used in boiler houses, steam systems and powerplants, which are one of the main objectives of ASME Code.
3. Miss Fernanda Cristina da Silva is one of my pupils at Mackenzie University in Sao Paulo. It was me who encouraged her to go the Library, make some research on Florida Snook's question and post an answer using my password, which she did without any interference from my part. Now, even if her answer wasn't entirely correct, she's proud for having posted it in such a prestigious site like AWS's one. I believe that professors should encourage their students to study, make research and then publish the results in some manner, even if they're not 100% perfect.
Giovanni S. Crisi
Sao Paulo - Brazil
Giovanni,
I think you've found a very good way to educate your students in the practical side of welding. Questions such as these are routine requests of a welding, materials or metallurgical engineer and it is good for the students to be familiar with locating and understanding material specifications and standards.
This material could be welded using a WPS qualified for P-8 materials since it has the same UNS number as materials that are assigned P-8. However, the A778 specification covers straight or spiral seam welded, unannealed tubular products and its end use is probably more suited to structural tubing rather than tubing under internal pressure. My point was that a manufacturer should not represent that it meets "SA778" by applying that marking on the material as that implies it is acceptable for use in pressurized systems or components governed by the ASME Boiler & Pressure Vessel Code.
Marty
I am pleased to see all the replys here and thank you all for your comments and thoughts. I went back out and verified that the pipe does in fact bear the SA778 markings. It is also apparent that the pipe came from Korea as well.
Final conclusion: if a steel product comes from a third world, underdeveloped country (even if the country is one of the so called "Asian tigers") what is written on it should be checked and double checked and never taken for granted.
Giovanni S. Crisi
By ArtR
Date 05-11-2003 22:18
Lets not pick on the other countries. You could say that about Texas too!
