Size of containment tank 1

[Bernoulli31]

Good day, everyone!

Question re: secondary containment of a tank.

Code says a containment should be "(vii) capable of containing at least 110 percent of the capacity of the largest tank or manifolded tanks that are connected in such a way as to permit the combined contents to spill, whichever is greater" (NYCRR Part 599).

IFC says: “Secondary Containment for indoor storage areas shall be designed to contain a spill from the largest vessel plus the design flow volume of fire protection water

How should the 110% be interpreted?

In my mind, if the containment "tank" has a volume 11% larger than that of the actual tank, it meets the intent of the Code.
For example:

PRIMARY TANK DIMENSIONS: 30" L X 22" W x 26" H
CONTAINMENT TANK DIMENSIONS: 52" L X 26.5" W x 14" H
Primary tank = 17160 CuIn
Containment = 19292 CuIn

Containment is about 12% larger than primary (>110%)

Does the code allow for the assumption that the volume of the tank that sits within the confines of the containment (to the height of the containment)is to be included in the usable secondary containment volume?



I design aqueducts in a parallel universe.

 

[UFT12]

Does the code allow for the assumption that the volume of the tank that sits within the confines of the containment (to the height of the containment)is to be included in the usable secondary containment volume?

If one sits inside the other and they share a common volume, can't think it can be otherwise. These are communicating vessels therefore how can the main tank be completely emptied into the containment?

 

[cdafd]

Containment can be a dikes area, or the floor, or a means to drain the liquid to a tank.

On tank in a tank, Someone else has to answer that, But if the inner tank leaks the secondary should contain the leak, and I am thinking does not have to be 110%

 

[LittleInch]

Yes it does.

Just need to be careful that the height of the tank floor is taken into consideration. Often a tank floor is raised above the containment floor level, but if it's the same the containment bund volume can be calculated including the tank volume itself.

But that width is rather small compared to the tank itself. A leak in the tank wall could easily create a flow which would leak outside the containment "tank".

A drawing always helps.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[Bernoulli31]

It's actually a Lift Station with double containment, see image.

Thanks for your responses! I did think the volume includes the tank itself. But because it's not spelled out anywhere and our AHJ can be pesky at times, I figured I'd ask.

I design aqueducts in a parallel universe.

 

[LittleInch]

Ah, that makes more sense.

By the look of it though any leak from any of that pipework will spray out over the containment tank.

And any volume of equipment in the containment bund needs to be removed from the volume available.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.