Calibrating Welding Machines - Any way to justify not calibrating the meters?

Hi Folks! I have worshiped you all from afar for awhile now, but just recently joined and this is my first post.

My question is this: is there any way to justify not calibrating the meters and thingamabobs on welding machines?

My Test Lab Manager, who oversees this calibration and for whom I have a great deal of respect based upon his experience and qualifications does not see this as a value-adding activity. I've received additional comments from the Manufacturing Manager, QC Manager, Welding Manager and Maintenence Manager all of whom claim to have a lot of experience in this area.

We are a custom manufacturer of power distribution switchgear and utilize welded construction. We certify our welders in-house within the criteria of AWS and do periodic destructive testing but nothing hardcore like x-rays and such.

I do not know a lot about welding yet, so I'm relying on what others tell me. Plus I'm a newbie to the QA field (went from Production Engineer to QA Manager in March and had to transition our entire QMS beast for the upgrade audit this week because the past two managers didn't do a lick of work) so I haven't had any time to address/research/think/dream about this particular issue.

I'm told that power flucuations(sp?) affect the machines and therefore welders use their own experience and rarely rely on the meters on the machine. I've told everyone we are maintaining the status quo and continuing calibration until I can feret out a solution, if any. Any advice and/or suggestions are welcome.

Don't know if this will be of any use, but here goes. Most welders do not go by the gages, except for a set up kind of thing, once they strike an arc, they readjust by their experience, and really don't pay that much attention.

I'm told that power flucuations(sp?) affect the machines and therefore welders use their own experience and rarely rely on the meters on the machine. I've told everyone we are maintaining the status quo and continuing calibration until I can feret out a solution, if any. Any advice and/or suggestions are welcome.[/QUOTE]
Hi, Welding is a special process, you must validate all the manufacturing element such as operator, equipment/meters,process,material,environment.
If your welding process is a continuous processing and defect will be consequent detected on the line, you do not need calibrate related meters used for welding machine.

is there any way to justify not calibrating the meters and thingamabobs on welding machines?

This is the means for the welder to verify his set up (a requirement). Calibration of weld equipment will only enable your AWS certified welders to adjust the equipment within the specified ranges to achieve a better weld. If your equipment is not calibrated your ranges for your settings are not a true value.

Yes and no,
I agree with the comments that they provide reference information to the welders. However, depending on the type of weld it could be a serious problem.

Before anyone jumps my case, let me say that I'm not suggesting calibration. We were experiencing cold welds from our spot welders, since you can't pull test spot welds on aluminium we ended up sending bad parts to our customer. Who, by the way, checked our welds by doing pull tests!
We installed a device that gives a print out of the current and voltage at the time of weld and will stop the weld if it is under a set amount.

How now....

Christi Day said:

Hi Folks! I have worshiped you all from afar for awhile now, but just recently joined and this is my first post.

My question is this: is there any way to justify not calibrating the meters and thingamabobs on welding machines?

I've told everyone we are maintaining the status quo and continuing calibration until I can feret out a solution, if any. Any advice and/or suggestions are welcome.

Click to expand...

Welcome to the Cove, Christi. How are you calibrating the machines now? What types of machines. Electric, Gas, etc.? I also agree with those that say that most welders turn their machines on and go. However, there are applications where the integrity of the welds are required to be verified, other than a visual inspection. With a little more information we may be able to solicit input from the Welding "Experts".

We use a Validator machine which puts a measured load on to a welding set,giving a Voltage/Amperage reading on the validator. This is compared to the readout on the dials/gauges of the welding set. We use this internally to test the welding machines that belong to our hire fleet.Our Validator is controlled within our normal calibration records, and is subject to annual external calibration. Any discrepancies are usually rectified in-house by our service team.
This ensures that the machines we hire out perform as they say they do. We have not been asked for proof of calibration yet, and we have been hiring equipment out for around 15 years.

Hi Christi and Welcome to the Cove ,


I will just repeat most of what has been said here. It depends on what your doing. I work for a sheet metal job shop. All our work is commercial, we build mostly cabinets and enclosures. We do not calibrate our MIG/TIG welding machines. We investigated the process at one time, and found it would not be of any value added, as our welds are not structural.

So to answer your question...what are you welding?

Carol

I know that you posted this in the 17025 forum, but I think the key here is what 7.6 in ISO 9001 says: "where necessary to ensure valid results, measuring equipment shall be calibrated or verified..."

Assuming you're talking about TIG, MIG, or some type of stick welding, I would argue that it's possible to ensure that the welds are good without having calibrated equipment. I'm currently working with a client that manufactures overhead cranes, where the CMAA requires AWS certified welders for all structural welds. In an audit last week, we reviewed many of the requirements of AWS D1.1. Nowhere in that document did I read anything about calibrated equipment - the requirements are focused on the results of the welding performed.

If the welders themselves are really qualified, they should be able tell while they're welding if they're getting a good weld. If the equipment went haywire, they should be able to tell because they wouldn't be able to get proper penetration, etc. Your periodic destructive testing should confirm that the welds are good. Have you ever had destructive testing failures?

The above doesn't apply if you're doing resistance welding...

Since the welder doesn't use the meters as process control, and since the meters aren't part of your product acceptance criteria, I see no reason why they'd need to be calibrated.