Question about my new steel tank (new to me).

[tridacna]

@rnln Where are you “pumping” it up?

 

[rnln]

OMG, lucky I didn't try. 120 inch lbs is only 10 ft lbs

tridacna,
A scuba shop near my place.

Thanks everyone.

 

[tridacna]

OMG, lucky I didn't try. 120 inch lbs is only 10 ft lbs

tridacna,
A scuba shop near my place.

Thanks everyone.

If they’re open, let them tighten it for you. Those bolts can be nasty when loose (enough).

 

[rnln]

It takes over a turn to get to 120 inch lbs. Either the valve is already loose and they didn't check, or they checked but didn't use torque wrench at all. It is tight and is not leaking now.

tridacna, at this point of time, I limit interaction with people as much as possible, and there is rumors that the covid-19 could be airborne. I was just worry if the tank slowly leaks down to empty, then it has a chance to get rust inside. Now, it stop leaking and still have 750psi. I am happy to put it aside for now

Thanks everyone again.

 

[halocline]

A LP 72 will definitely provide you with less air than a AL80.

Not if you fill them to 2700! Here are the capacities of LP72s at slight overfills:
2500 71.9
2600 74.7
2700 77.6
2800 80.5
2900 83.4
3000 86.3

So just a 225PSI overfill from the plus rating of 2475PSI gets you to the same air capacity as an AL80, in a tank that's quite a bit lighter on land AND less buoyant in the water. Not a bad deal at if you ask me.

 

[rjack321]

It takes over a turn to get to 120 inch lbs. Either the valve is already loose and they didn't check, or they checked but didn't use torque wrench at all. It is tight and is not leaking now.

tridacna, at this point of time, I limit interaction with people as much as possible, and there is rumors that the covid-19 could be airborne. I was just worry if the tank slowly leaks down to empty, then it has a chance to get rust inside. Now, it stop leaking and still have 750psi. I am happy to put it aside for now

Thanks everyone again.

The burst disk can be snugged up if it its leaking while there's gas in the cylinder but the torque won't be the same (due to the pressure)
Just put a socket wrench on there and give it a 1/8th or less of a turn. If that doesn't solve the leak it needs to be replaced. Don't muscle it or it will shear off and getting the remnant of the plug out with an eazy-out is a pain.

 

[rnln]

The burst disk can be snugged up if it its leaking while there's gas in the cylinder but the torque won't be the same (due to the pressure)
Just put a socket wrench on there and give it a 1/8th or less of a turn. If that doesn't solve the leak it needs to be replaced. Don't muscle it or it will shear off and getting the remnant of the plug out with an eazy-out is a pain.

Thanks rjack321, I'll keep that in mind. This time, I already torque it to 120 inch lbs with around 700psi in there. Hope I didn't break anything.

 

[rjack321]

Thanks rjack321, I'll keep that in mind. This time, I already torque it to 120 inch lbs with around 700psi in there. Hope I didn't break anything.

You'd know if it broke. The "bolt" is hollow brass and if you overdo it the nut on the end shears off.

 

[rnln]

so far it is still in one piece and was holding air last time I checked.

 

[AfterDark]

Not if you fill them to 2700! Here are the capacities of LP72s at slight overfills:
2500 71.9
2600 74.7
2700 77.6
2800 80.5
2900 83.4
3000 86.3

So just a 225PSI overfill from the plus rating of 2475PSI gets you to the same air capacity as an AL80, in a tank that's quite a bit lighter on land AND less buoyant in the water. Not a bad deal at if you ask me.

How much do ya get if ya pump an AL80 to 3600PSI?