7 replies to this topic

[uscme1997]

I have a chilled water system with an ASME Section VIII, D1 expansion tank. The expansion tank has an internal bladder, which is the connection to chilled water system (i.e. water inside of bladder). The tank itself is charged with air. Being that this is an ASME vessel, I need to provide pressure protection. Fire case is the only overpressure scenario. So instinctively I would think that the PSV should directly protect the tank and be mounted to the air side of the expansion tank. However the tank is a standard TACO design and has no connection for mounting a PSV. So I am left with mounting a PSV to chilled water connection side. Though I see issues with this design. Anyone have experience with this?

Edited by uscme1997, 03 May 2021 - 05:23 PM.

[Bobby Strain]

Please don't highlight! So, what is the source of the fire? Maybe you don't need a PSV for such.

 

Bobby

Edited by Bobby Strain, 03 May 2021 - 05:00 PM.

[uscme1997]

Sorry about the highlighting.  Not even sure how I accomplished that.  I will try to edit it later.  The fire case is just a scenario that can't be discredited, so we must provide a PSV to accommodate it.

[Bobby Strain]

Do you have any flammables in the vicinity? My guess is that you don't, unless someone brings in firewood.

 

Bobby

[uscme1997]

No flammables, but we have a Fire Hazards Analysis for the facility that does not discredit fire in this location.  I work at a Dept of Energy facility and we do things a little differently than the commercial/industrial world.

[latexman]

Is a "pool fire" probable?  It takes quite a large fire, like a pool fire, to heat a vessel and it's contents to the vessel's sizing T & P.

[Bobby Strain]

Sounds like a poor analysis. Done by amateurs.

 

Bobby

[fallah]

I have a chilled water system with an ASME Section VIII, D1 expansion tank. The expansion tank has an internal bladder, which is the connection to chilled water system (i.e. water inside of bladder). The tank itself is charged with air. Being that this is an ASME vessel, I need to provide pressure protection. Fire case is the only overpressure scenario. So instinctively I would think that the PSV should directly protect the tank and be mounted to the air side of the expansion tank. However the tank is a standard TACO design and has no connection for mounting a PSV. So I am left with mounting a PSV to chilled water connection side. Though I see issues with this design. Anyone have experience with this?

 

Hi,

 

You should install a PSV on mentioned pressure vessel for code compliance, either a fire case is applicable or not. Considering the bladder would rupture at a pressure much lower than vessel design pressure, appears installing the PSV at chilled water connection side can handle the over pressure due to fire case...