internal coating for lube oil tank

[kahlilj]

does anyone know if a horizontal above ground lube oil tank at atmospheric pressure needs an internal coating? or is this something that is done as a "best practice"?

is there a spec which requires this coating? if so can someone tell me what it states?

thanks,
kgj

 

[codeeng]

Most specs I've seen call for internal coating on carbon steel tanks. Smaller tasnks I've seen in stainless steel. Try also API-614.

 

[kahlilj]

thanks codeeng. however i dont have API-614... we rarely purchase tanks hence buying a copy is not justifiable (in my company/boss's opinion). so i'm kind of relying on a general consensus.

 

[rlewis]

The portion of the tank which is below the oil level will not corrode, however the portion above the oil probably will. You've also got a commissioning period when the tank is empty to worry about. Corrosion products from hte tank will contaminate the oil. For this reason, in critical services, oil tanks are made from stainless. For less critical services where you want to save some cost, I would recomend CS with a coating. You might get by with an uncoated tank, especially if you kept a dry air or nitrogen purge on it, but for my money, it isn't worth the risk.