When or how often should flange bolts be re-torqued?
When or how often should flange bolts be re-torqued?
(OP)
Guys here's a question... I am in a debate here as to whether flange bolts on ANSI (or API) flanges should be retorqued. I have not researched the issue but it seems to me that unless the fluid service is cyclic, or subject to vibration, that there is no need to retorque flange bolts. Your thoughts?
Thanks!
Pete





RE: When or how often should flange bolts be re-torqued?
RE: When or how often should flange bolts be re-torqued?
Another occasion when bolts must be re-torqed includes lined piping systems....particularly PTFE. Crane's resistoflex lined piping requires ANNUAL RETORQUING !
See
www.resistoflex.com/Flange_Bolt_Torquing.asp
Gasket Mfrs Recommendations and comments:
www.dracomech.com/gaskets/boltinfo.htm
It seems that most gasket manufacturers would like a retorque for any bolted application in order to ensure that gasket compression/creep has been given a chance to occur.....
Easy for them to say..... sometimes hard to implement
MJC
RE: When or how often should flange bolts be re-torqued?
Any leaks were tightened up online (luckily, we never had any leaks we couldn't stop this way). We didn't go through the entire unit again and retorgue everything although I could see the value of it when you are chilling equipment down from ambient to as low as -160C at the coldest.
Let me check with a couple of contacts at the local refineries and see what their practice is during a T&I.
RE: When or how often should flange bolts be re-torqued?