How many bolts are required for a manhole to be considered qualified?
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After the maintenance work at our factory was completed, the manhole bolts on many tanks and vessels hardly had been fully replaced (the workers were too lazy). I’m not sure if there’s any standard specifying how many bolts are required to meet the requirements
Check the diameter; refer to the flange fastener standards!
Check the drawings to find the standards for bolts, fasteners, and flanges； It’s indicated on the equipment drawings.
Hehe, the standard is no leakage
"It hasn’t fully recovered (the workers are too lazy) – what does that mean? Not installed completely? Is the torque not tight enough?
I should give you the minimum number of bolts; how dare you leave them uninstalled! Is it a pressure vessel? ! You guys are really too bold! We can’t afford to have problems! ! Each manhole has its own safety factor; it’s fine when nothing goes wrong, but once problems arise, it’s no longer just a matter of bolts!
Don’t say workers are lazy. Your management is really problematic; it is precisely because of your ‘laziness’ in management that the workers become lazy as well. Use as many bolts as there are bolt holes – there’s no need to discuss it! You mean, if possible, install less! No wonder.........
To ensure safety, it must be fully restored and tightened
Could it be that a high-specification manhole is being used in a low-pressure application? So they want to take shortcuts.
A serious accident occurred near me because the workers were too lazy and didn’t use all the bolts before starting the airtightness test. This led to insufficient strength, causing the equipment flanges and heads to fly off, which resulted in the immediate death of three workers who were working nearby and in adjacent workshops. This is a harsh lesson that must be learned.