Inspector-Welder Ratio

Ask the guys/gals at Caterpillar if you're after direct guidance.

My experience (factory down the road) is that the welders themselves are highly skilled and tested for competency before being allowed to perform critical welding and they "self inspect", so the ratio is 1:1.

Critical welding is catalogued as to which operator performed that part of the construction and traceability and accountability are then built into the quality system.

That metal fabrication plant (mining and rail equipment) had around 1 QA person per shed of 50 employees. Some Quality Assurance work was done, gauge control, tracebility and dimensional verification on finished work, so I guess that only a very small proportion of their time was spent on actual "inspection".

At one of our Construction Project of a Fertilizer Plant, this ratio is standing at 1:8 inspector to welder.

This depends on your QIPs (Quality Inspection Plans) as to how many witness / hold points have been included. Quality of welders at site also matters; repair rates.

There is no rule-of-thumb for such ratio, as far as I know. It just depends on many factors like quality of work needed, criticality of welding, necessary quality checks etc.

Regards,

Ashfaq Anwer

http://thepetrostreet.com

Good rule of thumb for ratio of inspectors to welders might be to divide average inspection time by average weld time.