CONCRETE FIREPROOFING FOR PRESSURE VESSEL

[mrivas23]

Good afternoon.

I have a issue with a pressure vessel that it is already ASME stamped. The relieve system is not acorde with the protect of the Pressure Vessel. The Cliente wants to protect all the pressure vessel with CONCRETE FIREPROOFING to guarantee the pressure below of the design pressure if there is a Fire situation, but we consider that it is not the best option beacuse the fireproofing is for protect the structural steel of the foundation.

Please, if you have any option for the solution of this isssue.. I`ll appreciate it

 

[TD2K]

Since your PSV(s) are not large enough and you won't/can't upsize them for whatever reason, you need to reduce the heat input during a fire to get the PSV fire case load within the capacity of the installed PSVs. That means you need to look at ways of insulating the vessel one way or another. Most companies don't like to take credit for insulation to reduce the fire case PSV load but if you are behind the 8 ball, I would consider it and that is what your client is apparently willing to do also.

I haven't seen fireproofing using concrete on the vessel itself though it is commonly used on the skirt or support legs. How much cement do you need to add? Are foundations designed for the extra load? You didn't give any details how big of a vessel you have, could that be why the client wants to use concrete? Do they have it on other vessels in the plant and are satisfied with it?

I would likely look at conventional insulation that has an upper temperature rating consistent with fire exposure like, say calcium silicate. Installation details are important, you want to use stainless steel cladding and banding that won't melt during a fire, the insulation has to remain in place if it's hit by water streams from fire fighting, etc. Remember, depending on the size and orientation of the vessel, you may not have to fireproof all of it. API 521 has a good discussion on factors to consider starting with section 4.4.13.2.4.2.

There are likely a lot of other options if you provided more details about the vessel, its contents, design conditions, etc.