LP Steel 80 Bottom Time

[diver72]

I recently purchased a PST Steel LP 80 (2400PSI) for boat diving. I usually use my PST HP100 for shore diving.

Is it safe tank usage practices to surface from a dive using my LP 80 (2400PSI) at lower than 500PSI?

I know I practice this philosophy with my HP100, but its service pressure starts at a much higher 3500PSI?

Thanks,
Chris

 

[JimC]

Each tank, each dive and each buddy require diferent gas managment. Part of the dive plan should include how much gas you need to get back.

The HP and LP tanks are going to require different psi readings for the same amount of gas on the same dive. For the LP 80, 1cf gas = 30psi. For the HP 100, 1cf gas = 35psi.

 

[DNAXdiver]

Not really the purpose of the 500 (or 700 or whatever) is as much to give you a cushion against gauge error which which is a constant, as a reserve for emergency. 500 is already on the low side by current standards.

Originally posted by diver72
I recently purchased a PST Steel LP 80 (2400PSI) for boat diving. I usually use my PST HP100 for shore diving.

Is it safe tank usage practices to surface from a dive using my LP 80 (2400PSI) at lower than 500PSI?

I know I practice this philosophy with my HP100, but its service pressure starts at a much higher 3500PSI?

Thanks,
Chris

 

[diver72]

I see... from a saftey perspective I can understand. I was concerned from a tank and corrosion view. I guess as long as there is some air in the tank it will reduce the chance of corrosion in side the tank.

thanks all.

 

[Goldminer]

Originally posted by diver72
I see... from a saftey perspective I can understand. I was concerned from a tank and corrosion view. I guess as long as there is some air in the tank it will reduce the chance of corrosion in side the tank.

thanks all.

I just purchased 2 PST LP 95's and the owner's manual that came with them said for long term storage keep 50 (fifty) psig in the tank. It seems you just need to be sure outside air can't get in.

 

[diver72]

Funny...I've purchased my 2 PST tanks from 2 different vendors and neither came with any manual. Where did you buy yours from if you don't mind me asking?

Good info thanks.

- Chris

 

[Goldminer]

Originally posted by diver72
Funny...I've purchased my 2 PST tanks from 2 different vendors and neither came with any manual. Where did you buy yours from if you don't mind me asking?

Good info thanks.

- Chris

I bought mine from Dive Source in Whitby, a town just outside of Toronto, Ontario.

They didn't exactly come with a manual. I bought the tanks just a few days after the shop received them and he hadn't unpacked them yet. They came in a plastic bag with the PST decal and Yellow warning decal not applied just tucked inside the bag. Additionally there was a single sheet of paper that briefly described the tank and care and maintenance for it. This was also just shoved in the bag. I kept one of them.

If you wish I could scan it and use some OCR software to post the text here or e-mail it to you. I will be travelling a bit in the coming weeks so it make take some time to get back to you on this.

 

[Goldminer]

OOPS!

I lied, must be the alzheimers. The tanks came with a 4 page fold out pamphlet with warranty info and care and maitainance instructions. The thermo valve came with the one page.

 

[diver72]

Yes! If you could get me a copy that would be great.

I really appreciate it.

- Chris

 

[Goldminer]

Attached is an OCR scanned version of Page 1 of the manual for PST LP cylinders. I have tried to scan it for mistakes and correct them. I can e-mail the text file to you if you wish.

Despite what it says my cylinders did not come with valves installed. They had red plastic blanking plugs.

PAGE 1

Pressed Steel Tank Company

Milwaukee, Wisconsin
Since 1902

CARE AND MAINTENANCE INFORMATION

Reference Part Numbers LP-80, LP-95, LP-104, LP-120

Congratulations! Your new PST AquaAire LP Pro cylinder is the
original steel scuba cylinder. It is more compact than aluminum cylinders
even though it does not require as high a filling pressure. These cylinders
are slightly negative in buoyancy even when empty, expect to use fewer
compensating weights due to the better buoyancy of these cylinders. This
design has been proven by over 40 years of success in the most
demanding scuba use.

Your cylinder has been fully assembled at the factory and includes a
standard K valve. An internal inspection is carried out just prior to valve
installation to insure a clean air supply. A special oxygen-compatible
halocarbon lubricant has been used on the valve 0-ring. This lubricant
gives a slight but distinctive pine odor. This does not mean the valve is
oxygen-compatible, but only facilitates qualified installation of a suitable
special valve for oxygen-enriched gas mixtures.

The exterior coating system on this cylinder is PST s unique real hot dip
galvanizing for the ultimate in lasting corrosion protection. The PST
process ensures durability by alloying the protective zinc coating to the
steel surface for peel-proof performance. With a little care, your hot dip
galvanized PST cylinder will resist corrosion in the harsh environment of
scuba diving. The zinc coating is sacrificial in nature and highly reactive.
Do not polish the surface for appearance sake. Hot dip galvanizing is an
industrial coating and will develop a mottled surface in time. Polishing only
thins the protective coating. Do not use strong acidic or caustic cleaners.
Use only cleaning solutions that are intended for galvanized steel.