Rectangular Mineral Oil Tank 2

[Chance17]

I am evaluating a 14"wide by 25"long by 15"tall steel reserviour used to circulate mineral oil through agitator seals.
Originally,the unit had a 3/4" breather vent but these were removed (and plugged)because of moisture concerns.
The rectangular lid opens with hinges and has two closure devices. Any inadvertant hinge closure could result in reservior overpressure.
I am recommending reinstallation of the original breather vent.
The client rejects any breather vent.
He insists the unit falls below a size limitation which does not require overpressure protection.
I can not identify any standard for size.

Question: Is anyone aware of size limits not requiring overpressure protection?

 

[Duwe6]

Possibly a 55-gallon drum.

It doesn't have to be a code requirement to make it prudent. Other than the requirement to pass hydrostatic testing, there is no requirement to install a complete floor in a API-650 tank. 650 just talks about the Critical Zone. Some things are self-evident.

The client's square tank cannot withstand over a couple of ounces of pressure without bulging and probably rupturing. All one of his operators has to do is close a valve on the outlet side on the tank while the circ pump is running and a catastrophe happens. Another scenario is for the agitator packing to jam up the oil flow, with the same results. If he won't listen to sense, get him to sign a waiver. When the tank blows, he'll want to blame anybody but himself.

 

[Latexman]

Was this supplied by a vendor or is it homemade? If a vendor, does the nameplate or literature call out any Code?

Good luck,
Latexman

 

[psafety]

There is no size limit. If an overpressure hazard exists it should be protected against.

The MAWP is easy to determine, these plates are small, if the thickness is known calculate the MAWP. Then the relief area can be determined. Don't overlook a potential vacuum hazard.