tank inlet nozzle

[raji@singapura]

Dear Members,

IS there any requirement for API tank inlet nozzle shall be inserted inside the tank by some length. Some of the design I saw is(ref attached fig) the inlet nozzle extended half of the tank from top.is it necessary? any guide line? please advice me!

Thanks in advance!
Raj

[ldmagar]

Dear Raji,
Yes, but not only for API tanks, it can be required for any tank depending on service. This is called dip pipe not a nozzle. Generally is given while handling saturated liquids. This is avoid the flashing of the inlet stream and thus avoiding vapour generation and in turn pressure built-up in the tank.
Also foaming services like caustic and others are always or should be provided with dip pipe. In this case, it is required to avoid foam formation in tank which may lead to wrong level indication or even may lead to tank overflow even when actual level is not high enough for overflow of tank.

Regrds,
LDM.

[Turk]

"Storage tanks has their liquid fill at the bottom and under normal operations they are never empty, so the entrance of the liquid is always submerged, so not to worry about static electricity."

Source: xxxx://www.eng-tips.com/viewthread.cfm?qid=91957