How to monitor those welding variables on-site ( Heat Input Parameters & Shielding Gases ) 4

[TOMMY2010]

Dear Members,
Hope you are all well!

Recently I am facing problems with monitoring those parameters ( Volt, Current, Travel Speed, Shielding Gas Quality and Flow rates)on-site and i am seeking advice on what is the best approaches to do so at the following situations;

***To make it clear and easy to understand i will assume that you are in a situation where you have to follow a WPS of SMAW welding for the (V,I,S) and any shielding gas process for (lpm and the quality of shielding gas)

Situation 1. SMAW Welding machine with both current and volt screens available but with a screen problem that you cannot see almost at all what are the readings.
Situation 2. SMAW Welding machine with only current screen available.
Situation 3. SMAW Welding machine with no screens at all and only knobs.

Knowing that all machines are calibrated and checked before starting the job.

What are the inspections needed for the shielding gas for quality and flow rate if you are going to monitor any welding process with shielding gas on-site.
- How to check quality of the gas itself.
- How to make sure the readings of the flow meter are correct?

***I know those questions might seems basic for you but I already take some actions in every situations but i need to confirm with you as professionals how to do it in the correct way.

Thanks in advance.

 

[Dhurjati Sen]

These questions are not basic, but the answers could vary with different approach.
There is a round-about way to check all these parameters, by not checking any of them at all.
Take RT of the first 5 joints done by each welder. If the welds are good, you can safely assume that all parameters are within range. Also, the welders are rightly qualified.

I feel that a welder is the best judge for his welding and so, he is the one who would be concerned with all these parameters.

DHURJATI SEN

 

[mfgenggear]

as with any parameters it has to be recorded and verified by quality, must be stamped off as approved, before they can proceed, and passes NDT, and generally done at the setup.

 

[weldstan]

Maximum heat input required for impact testing is often exceeded by welders when the PQR is made with unrealistically low values. Heat input can be monitored with the correct equipment and trained inspectors but not on a constant basis for manually produced welds.

 

[mfgenggear]

quote"Maximum heat input required for impact testing is often exceeded by welders when the PQR is made with unrealistically low values. Heat input can be monitored with the correct equipment and trained inspectors but not on a constant basis for manually produced welds. "unquote

seems counter intuitive, the reason to get approval is to correct issues, then a liaison engineer should change the requirements to what works within the spwcification.

 

[kingnero]

Best way is using your eyes and ears.
You can use weld data scanners or other monitoring devices, but I take my hood, have a look at them welding, and can pretty accurately tell the amps they're using.
When using GMAW or FCAW, voltage should be in a narrow range for an optimum arc, so UxI is covered by this. Travel speed: check length and time using a chrono (om your mobile).

For GTAW and MMA, Amps can be read from the source. If the source is validated/calibrated, this reading should be correct. If not, using a clamp-on amp meter only takes few seconds (be careful if special waveform, RMD, STT, CMT, forceARc, ..., pulsed or AC currect, this is also for GMAW/GTAW). Put on your hood, check arc length, and be confident that voltage is within a reasonable range. Check travel speed, and you're set again.

Newer sources tell power used in the last run. Devide by time/length, and you have your heat input. Some sources use arc efficiency (the EN-ISO way), some use total power (AWS method).

For shielding gas, a flow meter that can be put on the torch gives an indication of the flow rate.

ALways check labels on the wire spools, Tig rods, gas bottles, ... because that's where most of the errors happen. A welder worth its salt won't be using incorrect parameters, but incorrect materials happen more often than I'd've thought...

 

[gtaw]

Some newer welding machines have the ability to be monitored and the information recorded continuously via a WIFI connection.

Older machines can be monitored using periodic surveillance by a knowledgeable inspector. It seems unreasonable to assume the welder can concentrate on welding, especially manual or semiautomatic processes, and look at the meters on the machine at the same time.


Best regards - Al

 

[TOMMY2010]

@Dhurjati Sen, A great approach that should be respected and considered | Thx for you interest.
@mfgenggear , General speaking you are 100 % correct but what i meant with my questions is how actually i would do so i.e. how to check the current to record it what is the best method in those situations i mentioned in my post and how to do so with V, S …. | I am very grateful for your reply.
@kingnero, Actually a reply like yours is what I am seeking, your approach seems different but it has changed my attention to more that what i usually do, Thank you too much.
@gtaw, I hope those new machines will be available in my local market, even reading your post about it made me smile about how easy it will be, imagine my feeling if it became available | Thanks for your post.