Use of long bolt flanges - fire protection
Use of long bolt flanges - fire protection
(OP)
I have gotten conflicting opinions about the use and protection of long bolt style flanges in a chemical plant. One calls for the flange to be wrapped to prevent/decrease the amount of leakage in a fire situation. The other calls for leaving the flange open as the wrapping can cause corrosion. What experience have you had?





RE: Use of long bolt flanges - fire protection
The wrapping may lower the temperature locally to the bolts and should help but with all wrappings you may be susceptible to CUI.
Here is a case study in China and their countermeasures for such. http://shi
RE: Use of long bolt flanges - fire protection
RE: Use of long bolt flanges - fire protection
Steve Jones
Materials & Corrosion Engineer
http://www.linkedin.com/pub/8/83b/b04
RE: Use of long bolt flanges - fire protection
This is the second mention of long bolts that I have seen or heard within the last week. What is this about? Is this issue about long bolts such as non-flanged wafer style valves installed with through bolts? If so the solution is to prohibit wafer valves in hydrocarbon service.
RE: Use of long bolt flanges - fire protection
Don't know where the term originated, but yes, it is about wafer style components (not just valves, but also flow meters, etc.)
Donf
RE: Use of long bolt flanges - fire protection
If my choice, I would push back against the "insulation causes corrosion" response. If not generously painted exposed bolting will corrode. Option is to use expensive non-corrosive materials. Paint the bolting then apply insulation is the most cost effective solution. If money is no problem, then only use lug-style components where the bolting shorter and is not exposed.
RE: Use of long bolt flanges - fire protection
RE: Use of long bolt flanges - fire protection
RE: Use of long bolt flanges - fire protection
I asked our usual insulation contractor if it's something they do, and the answer was effectively "no", but he offered that they could make a removable steel mesh blanket with ceramic insulation within, but pointed out that there is a lot of liability when something needs to be fire resistant.
CCPS published a Safety Beacon on this matter - see attached.
RE: Use of long bolt flanges - fire protection
RE: Use of long bolt flanges - fire protection
The idea is the this will hold fluid around the bolts in case of leakage and the bolt temperature can't rise above the boiling point of the liquid
RE: Use of long bolt flanges - fire protection