Fusible plugs for Pressure Vessels
Fusible plugs for Pressure Vessels
(OP)
Could someone please provide additional guidance on fusilbe plugs? Per ASHRAE 15-2001
"9.7.2.1 Pressure vessels with an internal gross volume
of 3 ft3 (0.085 m3) or less shall use one or more pressure relief devices or a fusible plug."
I understand that if a pressure vessel is stamped with a U or UM symbol, then it requires a code certified UV stamped pressure relief device or UD stamped rupture disk, per ASME Section VIII, Div. I. But if a pressure vessel is not stamped with these symbols and is used in a refrigeration service (such as a receiver for an HVAC unit) and has an internal gross volume less than 3 ft3, ASHRAE tells me I can use a fusible plug. Is this correct? Do most applications that fall within these guidelines use these fusible plugs or do code stamped relief valves tend to be used instead? I guess I'm looking for a little experience in dealing with how these small vessels are dealt with. Thank you.
"9.7.2.1 Pressure vessels with an internal gross volume
of 3 ft3 (0.085 m3) or less shall use one or more pressure relief devices or a fusible plug."
I understand that if a pressure vessel is stamped with a U or UM symbol, then it requires a code certified UV stamped pressure relief device or UD stamped rupture disk, per ASME Section VIII, Div. I. But if a pressure vessel is not stamped with these symbols and is used in a refrigeration service (such as a receiver for an HVAC unit) and has an internal gross volume less than 3 ft3, ASHRAE tells me I can use a fusible plug. Is this correct? Do most applications that fall within these guidelines use these fusible plugs or do code stamped relief valves tend to be used instead? I guess I'm looking for a little experience in dealing with how these small vessels are dealt with. Thank you.





RE: Fusible plugs for Pressure Vessels
RE: Fusible plugs for Pressure Vessels
Fusable plugs are still used in gas storage applications at low temperatures. They have the advantage of not requiring record keeping or calibration. they can be used once.
They are an inexpensive way to meet the requirements of ASME VIII.
Good information from air products:
http:
They were first used in the first boilers (1830s) and have had a bad history in boiler (high temeperature) applications....Better to stick with relief valves..
http://www.steamtraction.com/archive/5509
-MJC