As been practiced at our work site minimun of 3 threads exposed out must be complied when tightening flange connection. Whether this a standard, I am not too sure aswell. I believe the manufacturer can advise you on stardard specification.
Hi there,
I just subscribed the eng-tips today. While surfing through I came across your issue and problem.
Well!... the problem that you have encountered is a common problem to the lip seal. At this point of time, there is no lip seal available that can 100% sealing especially with the mechine...