Calibration of Welding Machines ????

Date 04-15-2004 15:59

I don't believe it a requirement of d1.1 but usally it is a requirement of most customers. Plus it is the only way to prove to a customer that the equipment is in proper working order.

Brian J. Maas

By swnorris (****)

Date 04-15-2004 16:09

I am not aware of any code or standard that requires the calibration of welding equipment. There is a question on the AISC Quality Certification Program's Inspection/Evaluation Checklist for Complex Steel Structures that asks "Are welding machines periodically checked to ensure correct amp and volt readings and is a record kept (except SMAW)? This was a "critical" item on the checklist, and since 80% of the eight "critical" items for the operations part of the inspection must receive a satisfactory score, we wrote a procedure for the calibration and checking of welding equipment. Our procedure in essence states that all welding machines will be calibrated at least once a year by QC personnel, and a calibration sticker applied to each welding machine, with the date, the next due date, and the QC persons name. A permanent record will be maintained and kept on file in the QC's office. Amperage and voltage gages or indicators will be adjusted to read within +/- 5 % of actual readings obtained from voltmeter and ampmeter. In the event a machine cannot be calibrated to the proper requirements, it will be removed from service until the necessary repairs are made, and it will be so noted on the permanent calibration report. Voltmeters and ampmeters used for calibration will be certified for accuracy and their certificates will be maintained on file in the QC's office.

By CHGuilford (****)

Date 04-15-2004 16:13

D1.5-2002, 4.26 requires that accuracy of meters or whatever is used to measure and record welding variables be checked every 3 months. Equipment used to verify accuracy must be certified annually.
I'm not sure about other codes requiring calibration.

Chet Guilford

By jwright650 (*****)

Date 04-15-2004 17:02

Hi jon,
I get asked every year during our AISC audit about those welding machine calibrations and I have to pull out the paper and show them the gages used and then they ask to see those gage calibration papers also.
John Wright

By jon20013 (*****)

Date 04-15-2004 20:40

Yeah, I appreciate all the input. I guess for myself, being in the nuclear fabrication discipline, I am sooooooo bogged down with REQUIREMENTS that someone requesting something what isn't REQUIRED by Code kinda gets my dander up. For our equipment, I always check with calibrated gages when we're doing a PQR but for our other work, I just check maybe every few months. Believe me, my welders are the first to complain when their machines are running properly so I guess to me, it seems a rather mute point. So, how do you guy's handle issues where there are no REQUIREMENTS simply some auditors opinion of what should or shouldn't be? Personally, I have no problem at all simply stating "show me the requirement and I will comply."

By CHGuilford (****)

Date 04-15-2004 21:40

I guess it depends on how much clout the auditor has. At the least I would give a listen along with some polite head nodding, and ask where in the specs it says that. You know....those code books "all blend together after a while and we always appreciate the help in keeping everything straight".
I would avoid promising to fix the problem until I had a chance to verify there really is a problem. If it is, I address it immediately; if not, I keep the "suggestion" in mind.

Calibrating welding machines has been a pet peeve of mine as well. Our shop is certified for bridges so we have to comply with AWS D1.5 and do our checks every 3 months. But no one seems to agree on the best way to do that. What I can't justify is putting a load cell on our power supplies, measuring varied outputs, and plotting a graph to correlate machine readouts to the measured output. It takes a lot of time, the results go out the window when welding conditions change, and our people like to play "musical machines". I try to keep my calibrations as simple as possible and so far, auditors have not taken exception to my methods. But if someone has a good way to do this, I'm all ears!

Chet Guilford

By jon20013 (*****)

Date 04-16-2004 13:38

Yeah, I do check our machines periodically which I think is simply good practice, and am probably just venting from having customers trying to push requirements where there are none established. Thanks for the input!