If the motor on the modine dies, keep your eyes open, because through the dealer they are 340 green, If that doesn't knock you on your butt, remember old radiators (hot water are the ticket.)
The reason I know about the 'burst pressure' is 8 years ago a local college had 2- 10,000 gallon tanks buried in a parking lot that used a 275 oil tank as a 'day tank' inside to temper the fuel before it hit the boilers.
The HVAC guys were on the roof in Feb, and piled wet, slushy snow on top of the system vent pipe. -20 that night........froze the entire vent system.
Boilers called for heat all night, day tank activated the pumps in the 10,000's, so trying to make a balloon out of a 275 was not pretty. Security CAUGHT IT AT 05:00. 3300 gallons of #2, 8" deep and it was flowing to the sump pit for the building which pumped into the municipal sewer. Engineering data later said the 275 tank is safe up ONLY 5 psig.
WTF was not even thought of. Clean Harbors was there for 3 days, never saw the bills, but it was a mid-level 6 digit number.
You all know the smell when you get a few drops of diesel on you clothes.....this was making people sick to just enter the building.
Soooooooooooooooooo NO un-rated tanks please.