tank's drain size

[wormhhh]

Hi,there:

I am wondering that is there any general guide on how to decide a low pressure tank's drain size based on the tank's design data, such as height, diameter and capacity?

Thanks.

 

[proinwv2]

Well there are several factors for you to consider including how fast do you want it to drain. The actual rate of flow will continually decrease as the head falls.

Flow rate is controlled by head pressure, including any pressure in the vapor space, fluid properties, drain opening geometry, and drain fittings and piping.

Crane Tech Paper 410 is a good reference for starting your calcs.

Paul Ostand

http://www.ostand.com

 

[SmartEngineer]

I think this is generic question as many factors fall on the selection of drain size of tanks.
Such factors are steam-out purposes, size of the tank, material stored..etc

I have seen various drain sizes as 2" for small tanks and 6" for large tanks

Hope this would help

cheers
SmartEngineer

 

[sshep]

High volume draining of a tank is one of the more common ways to suck in a tank, and this should be considered in the vacuum breaker sizing. Another thing to check is the flow that can be accomidated by your sewer system if draining to such a collection system.

My opinion is 2" for a small tank is adequate, while 4" is reasonable for most purposes on larger tanks.

best wishes,
sshep

 

[Ashereng]

The assumptions here is that the tank is gavity drained.

If you expect buildup on the bottom of the tank (e.g wax, sludge, sand, etc.) and the tank needs to be pumped/vacumed out, then the drain size may need to be larger.

 

[wormhhh]

thanks for you guys information. appreciate it.