LP 104 or HP 120 for single use?

[globaldiver]

Would there be any advantage to buy a PST LP 104 over a PST HP 120? The tank/cylinder is intended for single tank diving, with an H-valve configuration. Having a 104, it would mean more weight to log around on land, and the 120 seems a bit easier to handle on land when diving singles.

Besides a more constant airfill, are there any other advantages to purchasing a single LP 104 over the HP 120? I do not intend to use this tank with EANx.

Any input?

Sincerely

Anders

 

[Scubaroo]

Have you checked the availability of 7/8" threaded H valves? I think you're limited to Genesis valves. Aren't these the ones with a funny angle on the main DIN valve, so your regulator sticks up higher? Somebody else on the board can probably clarify this.

Also, 120cf of air is a lot of air on each dive if you plan on doing multiple dives a day. I haven't got an RDP handy, but you might want to plan a few typical dives and see if you're setting yourself up for some long surface intervals to offgas to avoid running into NDLs.

cheers

Ben

 

[large_diver]

- HP120 is slightly taller. If you are a short person, you probably don't want this tank.

- Fills -- many shops can't give you a "full" 120 after cooling. My shop asks for a few days on HP tanks so they can let them cool and keep topping them off over this period. Kind of tough if you are in a hurry......

 

[globaldiver]

I am using an OMS 3/4.14" H-valve, and I am 6'2"/200lbs. I used to dive with a 15L/95cf Heisser tank in Sweden, and either way I will get a bit more air compared to that. Tha Heisser tank was built very solid, but was more weight logging around on land, and not much different in the water compared to a Faber of the same size.

Any other benefits with either the 104 or the 120?

Sincerely

Anders

 

[rcohn]

You can get the DIN valves in both angled and straight versions, on four HP tanks we have three which are straight and one angled.

One big advantage of the 120 in this area would be you could get 120 cf in it. Nearly all shops won't overfill the LP tank.

You can get a good fill by letting the tank cool and then topping it off once. This doesn't require days, it takes about a half hour. I usually leave my tank at the shop and they top it off quickly when I come to pick it up. If I need them right away I can wait for it to cool or take it as is. Most shops in this area will deliver 3200 to 3300 psi after a hot fill without topping off.

Many shops don't want to take the time to cool and top off a tank which leads to the short fills, but this is a problem with the 3000 psi Al tanks as well.

Ralph

 

[Scubaroo]

Originally posted by globaldiver
I am using an OMS 3/4.14" H-valve

Check their website - the HP tanks require a 7/8" valve. Assuming you already own the OMS H-valve, it won't fit a HP tank.

 

[globaldiver]

You are absolutely right, I did not think of that. 7/8.16" neck threads instead of the 3/4.14", probably due to the higher pressure.

I'll go for the 104 then. Could be worse, I dove with one previously and liked the balance it gave. Need to train my muscles anyway...
I may get a HP 120 anyway for air, and use the 104 for EANx diving...

Anyone who knows where I can get a good priced Genesis H-valve?

Sincerely

Anders