Structural Design Weight --- Tank Capacity vs Actual Contents
Structural Design Weight --- Tank Capacity vs Actual Contents
(OP)
I have a client who needs structural support (gravity and seismic anchorage, calcs and sketches) for a Demister Tank located on a roof. The tank will fume scrub for gold & copper for an industrial building (high-tech). The tank capacity is 5174 gallons, but client insists it will only ever see 24 gallons (200 lbs) maximum contents + tank self-wt = 1450 lbs. I'm looking for a code reference that would show my client that we need to design for the tank capacity and cannot design for an arbitrary limit.
It would not be efficient to design for the capacity (~45 kips), and I'm hoping to steer him to a smaller tank that we can design for the capacity of. But does anyone know of a reference for something like this?
If they choose to stick with the enormous tank I think I will walk away from this little project for liability reasons (future building owners, facility managers, etc.). Thanks in advance!
It would not be efficient to design for the capacity (~45 kips), and I'm hoping to steer him to a smaller tank that we can design for the capacity of. But does anyone know of a reference for something like this?
If they choose to stick with the enormous tank I think I will walk away from this little project for liability reasons (future building owners, facility managers, etc.). Thanks in advance!






RE: Structural Design Weight --- Tank Capacity vs Actual Contents
I'm not familiar with demister tanks. On tanks in general, you'd design for a liquid level to the overflow, not necessarily full to the top. So if the tank configuration there is such that it couldn't reasonably be filled full, it would make sense to design for actual operating weight. If you're just kind of on the honor system that it won't be filled, I'd opt for "full" design weight. If any foreseeable circumstances would result in the tank being filled (clogged pipes, faulty controls, whatever), I'd opt for "full" design weight. It sounds like a failure there would result in the tank falling through the roof, so it's a bit more critical than a free-standing tank would be.
Example: If you had an air compressor tank, it might accumulate minor amounts of water in it, but you wouldn't assume it was full of water for design purposes.
RE: Structural Design Weight --- Tank Capacity vs Actual Contents
RE: Structural Design Weight --- Tank Capacity vs Actual Contents
Yes, capacity is 5174 gal with 419 gal unfillable in dome. Not sure why the need for such a large tank.
RE: Structural Design Weight --- Tank Capacity vs Actual Contents
Tell your client that the design weight is going to involve the 5174 gal. cap’y. weight. Or alternatively, you plan to cut several 12" dia. holes in the side of the tank at the 24 gal. cap’y. height.
RE: Structural Design Weight --- Tank Capacity vs Actual Contents
Dave
Thaidavid
RE: Structural Design Weight --- Tank Capacity vs Actual Contents
RE: Structural Design Weight --- Tank Capacity vs Actual Contents
For combined seismic and tank loading I would suggest designing to normal seismic requirements with the tank at operating weight, and check that the structure would not collapse with combined seismic load and the tank at its maximum possible load.
Doug Jenkins
Interactive Design Services
http://newtonexcelbach.wordpress.com/
RE: Structural Design Weight --- Tank Capacity vs Actual Contents
RE: Structural Design Weight --- Tank Capacity vs Actual Contents
RE: Structural Design Weight --- Tank Capacity vs Actual Contents
Doug Jenkins
Interactive Design Services
http://newtonexcelbach.wordpress.com/
RE: Structural Design Weight --- Tank Capacity vs Actual Contents