LP85 filled to 3600psi?

[XS Scuba]

You are wrong.

Correct me if I'm wrong but I believe the only difference between a LP and HP steel tank is about $80.00. Same dimensions, same material, just that they have been rated to higher pressure by the Mfg.

 

[Nemrod]

I take my two Faber LP 85s to 3,000 psi routinely. N

 

[ScubaSarus]

They can be overfilled but it is a gamble (risky) and the tanks may fail hydro sooner than usual. Another reason not to buy used tanks from cave country and know that the previous owner didnt always overfill them.

 

[tonka97]

4000+ Ill assume that we are talking HP's? If not WOW!!

Correct me if I am wrong but wouldn't the burst disk need to be changed on an LP for the 3600 fill? I was thinking 3500-3600 was the disk pressure.

This is what I have gathered from the web; I have no direct experience:

The burst disks are replaced by a higher pressure disk, doubled, or even replaced by a solid plug.

Some divers consider the burst disk a failure point and prefer the solid plug omitting the burst disk altogether.

 

[Jim Lapenta]

I regularly take my lp's to 3000 plus. Also mine came with 5000psi discs or I replaced them with those. Never had a problem getting fills anywhere. I do use 2 or 3 shops on a regualar basis and none of them have an issue with this. Of course I'm always there when they are being filled or will soon be filling them myself. Doing gas blender in a few weeks.

 

[tonka97]

Is it the weight and cost of the HP cylinders that bias many divers toward the LPs?

Of course, it is only the cylinder's buoyancy characteristics that matter in the water not the dry weight of the tank. (other than inertia)

Seems if a diver wants to overfill a tank, the choice should be a tank designed for higher pressures.

HP steel not LP steel.

True or False?

There is an inconsistency I've noticed. Much of the criticism of the HP steel tanks has to do with "you can't find shops that will give you a good fill, IE 3442 psi." But there seems to be NO problem finding shops that will fill a LP+10% steel cylinder to that pressure or higher.

 

[Web Monkey]

I recently got a fill at Dive Tech (sort of near Kingston). When I picked up my LP (2640PSI) steel tank, it had 3500PSI and was so hot I couldn't hold it.

I was unbeliveably ****ed. With any luck it will still pass hydro next time

By the next day it had cooled down and was less than 100PSI over.I can't even guess what kind of fill rate it would take to do this.

Terry

A steel LP 85 cf is rated 2400 psi + 10% overfill = 2640 psi

So called cave fills pressurize this low pressure tank to 3600 psi. (2400 psi +50%)

Reckless or not?

 

[xiSkiGuy]

Is it the weight and cost of the HP cylinders that bias most divers toward the LPs?

It is only the cylinder's buoyancy characteristics that matter in the water not the dry weight of the tank.

Seems if a diver wants to overfill a tank, the choice should be a tank designed for higher pressures.

HP steel not LP steel.

True or False?

I'd say cost was/is the major factor. For example, scuba.com has X8-119s for $344.95. They sell LP95s for $299.95. The price gap used to be even wider.

Occasionally not having a firm grasp of the pressure/volume relationship plays into it as well: "My LDS kept short filling my E8-130s to 3300psi, so I bought LP104s instead. They overfill them to 2800psi!"

Sometimes the LP tank you like doesn't have an exemption equivalent. If you like LP104s you can buy X8-130s, but no one makes an exemption version of the LP85.

Buoyancy characteristics vary from brand to brand and LP to exemption. Sometimes getting the buoyancy you want means buying the LP version.

LP tanks have been around a lot longer than exemption tanks, and have a larger following: "I really like my LP108s. You should get some, too."

 

[all4scuba05]

In about 3 years I'll know wether overfilling the LP85 tanks will automatically cause them to fail the Hydro test. I considered them an experiment when I bought them.

 

[Soggy]

If it is that unsafe, tanks would be exploding and failing hydro left and right in North Florida.