Quick story; A few years ago we had a "Expert" consultant come and inspect a job we were doing for the client. I left him with one of my project managers to do the inspection. We were using M12 A4/316 stainless bolts to secure some big structural brackets holding up some pretty heavy kit. We got a copy of his "so called" report and he sighted the nuts on the bolts as not being torqued to the correct setting.
I asked my manager what had happened and he told me the "Expert" had produced a calibrated torque wrench to check the nuts. He had told him they were all set and paint marked as part of our QA procedure.
The client insisted the "Expert's" findings should be acted on and we should re-torque the nuts. I insisted on a contractual instruction. A few weeks later the "Expert" came back ad reported they were still not right. We explained the properties of 316 but he knew better.
Needless to say, it was not long before the bolts started to fail. The heavy bit of kit was soon hanging on 75% of the designed fixings and these were in danger of failing too! Suffice to say we got paid to replace all the bolts on night work at a premium. I also charged them for the abortive time and the attendance at the inspections :-)
Some of the bolts that were 250 mm long when fitted were stretched by 10 mm.
Moral of the tail is "X is an unknown quantity" and "a spurt is a drip under pressure!" Its good to trust experts but its better not to!
There is no substitute for experience!!!
Ant.
