How long to drain a 74 Cu FT Omega tank from 2800 psi?

[RAJOD]

Had a faulty gauge on a new Omega 74 cu ft tank.   

Guess how long it took to drain the air from 2800 psi with valve open and hose off?

1.  2 minutes
2.  10 minutes
3.  30 minutes
4.  45 min
5.  1 hour
6.  2 hour
7.  3 hours

[Motorhead]

1.  2 minutes

[RAJOD]

1.  2 minutes

Nope it took "Drum roll"  2 hours to drain the tank from 2800 psi to 0.

I've never done it before but 2 hours seems a bit much.  Maybe they have some kind of restriction in the head.   I'll have to try it on my shark tank sometime and see if its just as slow.

[Taso1000]

Bob,

I forgot that some of those valves do have a "slow flow" feature.

Taso

[RAJOD]

Bob,

I forgot that some of those valves do have a "slow flow" feature.

Taso

On this tank they do the slow flow past the head and it was never installed.  It fills gun tanks fast.   Yes my shark tank does have a slow flow feature inside its head.

[rsterne]

If it took 2 hours, it has a restrictor (or at least a restriction) in it.... one tiny enough to provide sonic choking....

Bob

[RAJOD]

If it took 2 hours, it has a restrictor (or at least a restriction) in it.... one tiny enough to provide sonic choking....

Bob

Not sure what sonic choking is but yes agreed there is some kind of restriction.  I don't know if its intended from Omega or something is off with this tank.

[Dairyboy]

That does seem like a really long time

[rsterne]

If an orifice is tiny enough, the air coming out reaches Mach 1, and that limits the flow rate, depending on the pressure across it.... it's called sonic choking....

Bob

[RAJOD]

If an orifice is tiny enough, the air coming out reaches Mach 1, and that limits the flow rate, depending on the pressure across it.... it's called sonic choking....

Bob

Thanks for the clarification.   

It seemed to fill up at the firehouse slower than my Sharktank it took much longer and probably got warmer too.   When both tanks cooled the Shark Tank had 4600 psi
and the Omega had 4000 psi.     Just wondering if anything changed in the tank.

I know in my Shark Tank the slow fill did not work for 2 years, it was super fast fill into the gun, really had to be careful on the valve when filling.

Then I had it filled at the scuba shop and when it came back the slow fill was working for the first time.   Its very slow.   

Next time I fill my Sharktank I'll drain it and see if it is as slow as the Omega.    I'm just asking because its still under warranty only a few months old.   Wondering if something changed in the head somehow.   

[rsterne]

If something changed, I would be a bit concerned that a piece of debris was plugging the outlet.... If it plugs it completely, you will not be able to empty the tank, I heard of one case of that happening.... I would drain the tank and remove the valve and find out what is going on....

Bob