Do pressure vessels Anchor bolts need torquing
Do pressure vessels Anchor bolts need torquing
(OP)
Hi, One of the spec says once pressure vessels are installed on foundation ( Anchor bolts are concrete bound) , nuts have to be torqued to a pre determined value. Specification gives tensioning values based on Anchor bolts dia and Material. Do we have any value in tensioning concrete bound bolts? Does any standard recommends static Equipment Anchor bolts need to be torqued ? If so please refer.
Thanks a lot,
Thanks a lot,





RE: Do pressure vessels Anchor bolts need torquing
Most vessel baseplates / chairs / anchor bolts are not designed to be pretensioned. In this case, "snug" is the operative term. But a very few vessels, typically of the large variety and in heavy wind or seismic areas, are designed with pretensioned anchor bolts. These add a couple bolts (half the bolts plus 2 usually) acting in tension to counter the overturning moment.
My thoughts on the matter: It is difficult enough to get pressure containing flanged joints tensioned properly. To have 49 vessels in a facility with no torque requirements and 1 "special" is asking for the pretensioning to not occur, or to not be maintained. So I'm generally opposed to the notion but open to a one-off argument for a particular case if somebody were to bring one up for my review.
The ASME Post Construction Committee has had a long-term effort to write an article for PCC-2 which would include this issue. It's been stalled out for years primarily because of the pretensioned anchor bolt issue. The possibility exists that the article might make it into the 2018 edition, but I won't be expecting it to happen.
RE: Do pressure vessels Anchor bolts need torquing
Regards
r6155
RE: Do pressure vessels Anchor bolts need torquing
I suggest you to read Pressure Vessel Handbook by Paul Buthod for anchor bolt calculation.
RE: Do pressure vessels Anchor bolts need torquing
2)Horizontal vessel
Fixed saddle: as per 1)
Sliding saddle: hand tight
Regards
r6155
RE: Do pressure vessels Anchor bolts need torquing
RE: Do pressure vessels Anchor bolts need torquing
In most cases for vertical PV required bolting is defined due to condition of empty PV + wind
When the PV is in service, can we say 99 % of the time, required bolting is less.
Do you understand that fatigue analysis need to be considered during 1% of the time (empty PV +wind)?
Regards
r6155