so many issues with a tank 1

[darthsoilsguy2]

ok... so i'm asked to look at a tank to give a design for a manway addition to an existing tank. When we got there, we found out that

1. the tank was an excavated UST that has been empty for a while and now they want to use it to hold acetone and other flammable solvents with high vapor pressures.
2. they don't plan on venting it.
3. the tank has a massive dent on one side (probably from the excavation).

i don't mess around with pressure vessels so i can't say much about it, but i feel like they will be wasting their time with this tank if they won't vent it. any advice? have you crossed this before?

 

[IFRs]

Walk away while you still can!!

 

[darthsoilsguy2]

:-D IFRs

hee-hee, i know it. i'm outside of the blast zone at this moment... (j/k , it's not in service right now)

We briefly discussed them getting a tank integrity study done. i want to tell them they'll need an engineering evaluation for the change of use issue too. they have a consultant that puts out a pretty solid report. i'm throwing this post out because i think they would be wasting their money to go after a study without conceding that the tank will need to be vented from the get-go. the venting may be a deal-breaker for them. if some people with pressure vessel experience agree with my hunch that it would be a waste, would your opinion change if the tank wasn't damaged?

 

[skearse]

I'm confused. Without venting it, are they planning on letting the tank hold pressure/vacuum when they are filling & pumping out?

 

[ronfrend]

If they do not vent the tank they MUST install a PSV or a PVV. If the tank is to be legally operated as a pressure vessel the operating pressure must be determined and the PSV set from there.

I think the owners should find out the local regulations - someone might end up in serious trouble if anything goes wrong.

Work out the Potential Impact Radius and keep WELL away.




Ron Frend

http://www.predicon.net

 

[Unotec]

old, not vented, requires modifications, not a pressure vessel or if it is, any modifications or dammage forces for re-certification, high volatility fluids and on and on....
scrap it and get a new one designed for its use

<<A good friend will bail you out of jail, but a true friend
will be sitting beside you saying ” Damn that was fun!” - Unknown>>

 

[chicopee]

I agree with Unotec, get rid of the tank for that application.

 

[stookeyfpe]

I've seen people attempt to convert a UST to an AST. It doesn't work when you compare the head thickness requirements in UL 58 to the requirements in UL 142.

The fact that the tank does not have an emergency vent places firefigthers in danger if the tank is involved in a fire.

If that tank was (or is) in my jurisdiction, the tank would be legally declared an imminent hazard and the owner would be charged with criminal negligence.

Tell the owner to enjoy the ride in backseat of the police car....