External Installation on reactor vessel

[Leonrossi]

Hi Experts,
I need to upgrade the insulation on 3000 gallon stainless steel reactor vertical vessel for my company. The existing insulation is 3" mineral wool on the side and 2" fiberglass on the bottom. The reason for the upgrade is that the relief device is not big enough to handle the external fire case scenario. we cannot upgrade the relief device and hence the only cost effective way we can reduce the heat input is to upgrade the insulation. I've done the calculations to determine thickness of insulation for various materials- calSil, Superwool-HT, and ceramic fiber. According to API 521 section 4.4.13.7.2., the insulating material must function effectively at temperatures up to 604 deg C (1660 deg F) for up to 2 hrs. calSIL, Superwool-HT, and ceramic fibers meet this criteria but they have drawbacks, such as being expensive, high labor cost to install, presence of chlorides, carcinogenic, etc. I would like to use the mineral wool, but it doesn't meet the criteria of 904 deg C(1660 deg F). the maximum temperature of mineral wool is 1200 deg F. Another engineer told me that i can use the mineral wool. My question is, can i use the mineral wool even though is below 1600 deg F, or is any any provision is the code to allow me to do so?

I greatly appreciate your feedback

Regards,
Leon

 

[SwinnyGG]

I use a pretty general rule of thumb for anything involving an argument between someone's word and governing code. Unless they can provide you a code reference that says you can violate code in the way they say you can, assume they don't know what they're talking about.

Regardless of cost, don't get caught violating your governing code. Sounds to me like you can't use the budget option here.