Another propane storage tank question

[woodsmaster]

Hi,
Getting ready to cut and weld fittings on 2 - 500 gallon tanks going in vertical. I'm planning on plumbing them parallel. There is a 1 1/4" drain on each tank that I thought I would use for return. Is this big enough or should I go 1 1/2".

I thought I would go 1 1/2 to and from boiler and split it to 1 1/4" to each tank. 200,000 btu boiler.

Then should the other hole be on the very top once stood up with a t and valve for air removal on one side of t and the supply on the other side of t ?
Hope this makes since.

 

[ewdudley]

Hi,
Getting ready to cut and weld fittings on 2 - 500 gallon tanks going in vertical. I'm planning on plumbing them parallel. There is a 1 1/4" drain on each tank that I thought I would use for return. Is this big enough or should I go 1 1/2".

I thought I would go 1 1/2 to and from boiler and split it to 1 1/4" to each tank. 200,000 btu boiler.

Then should the other hole be on the very top once stood up with a t and valve for air removal on one side of t and the supply on the other side of t ?

I hope it makes sense too because that's pretty much what I ended up with, although I did go with 1.5" since I had a bunch of fittings in the scrounge pile.

Assuming 20 gpm you would only have 2.65 foot per second water velocity through each of the two 1.25 ports. If the boiler actually puts out 200000 btu per hour you're going to need on the order of 20 gpm to get rid of the heat. 20 gpm through the 1.5" piping to get to the 1.25" would be traveling at 3.6 foot per second, which is slow enough, assuming your boiler is adjacent to the tanks.

My tanks are set up to incline slightly up to an air vent on one end of the top manifold.

Also I welded ports to the very bottom of the tank same as on the top so as to take advantage of the last drop of storage, since I was able to build high enough to accommodate setting the tanks high enough to tap into the ends.

--ewd