Question Which one's to keep...lp 85's or hp 120's

[jcee]

Hello All,

I was given a pair of PST HP 120, din valve only 7/8 inch thread and a pair of Faber LP 85, 3/4 inch thread pro valve. I don't have the space to keep both pairs so which one's should I keep? A bit about me, I do mostly recreational shore dives in northern California, Monterey Bay. I'm 5'10', 190 lbs.

Thank you everyone in advance.
'

 

[rjack321]

Hello All,

I was given a pair of PST HP 120, din valve only 7/8 inch thread and a pair of Faber LP 85, 3/4 inch thread pro valve. I don't have the space to keep both pairs so which one's should I keep? A bit about me, I do mostly recreational shore dives in northern California, Monterey Bay. I'm 5'10', 190 lbs.

Thank you everyone in advance.
'

I'd keep the 85s. I'm 5'9" and the 120s are far too long for me, and I find them crazy heavy too. Not to mention the 7/8" valves are a big pain in the butt and getting worse.

 

[rob.mwpropane]

In with @rjack321. I'm 5'11". I can dive the 120's but I prefer the LP 85s. I have mine doubled up, not sure if that makes a difference.

 

[Sevenrider860]

I find the LP85 to be a very versatile cylinder size for all types of diving. If it was me, I would sell the 120s.

 

[ND5342]

I know you said you don't have a lot of room but if you can...I would sell one of the 120s and get your self a transfill whip so that you can add a little more gas if needed to your 85's. I take my LP tanks to 3000 all the time and down in Florida cave country those tanks would be filled to 3600 psi

 

[tbone1004]

Hello All,

I was given a pair of PST HP 120, din valve only 7/8 inch thread and a pair of Faber LP 85, 3/4 inch thread pro valve. I don't have the space to keep both pairs so which one's should I keep? A bit about me, I do mostly recreational shore dives in northern California, Monterey Bay. I'm 5'10', 190 lbs.

Thank you everyone in advance.
'

If just looking at the tanks themselves, I would keep the 120's. No brainer. They are hot dip galvanized which will hold up to the salt considerably better, you are unlikely to have a reliable source of cave fills for the 85's so they hold more gas in a lighter weight package, and they are about 2lbs more negative so your net rig weight will be considerably lighter.

Both of them are probably too long for you to wear as a single tank though, I use HP120's as my primary backmount tanks they are almost too long on me at 6'3".... The 85's are less bad, but you'll probably still find them on the long side. You can probably trade them in your area for a HP130 or 119 *short and 8" wide versions of the 120* and that would be much more comfortable for you.

 

[lexvil]

I’m 6’5” and don’t really like 120’s, if you can get the 85‘s filled next to AL 80’s all of the time (they look and feel like an 80) pumped to the 3000/3200 range they are great tanks.

 

[formernuke]

I'm 6 foot 2 inches, used to dive 120"s. I've since sold them and use hp100's which are very similar to 85's when I actually dive single tank.

 

[ND5342]

If the 85s are painted I would not worry too much as long as they pass their visual and/ or hydros. I have many painted tanks in my inventory And as long as they are rinsed off properly they will last forever. The biggest problem I saw from working at shop and visualizing hundreds of tanks is you especially need to remove the boots especially on the 85s as they have a horrible boot design. Get a cheap plastic mallet and just make sure to pop the boots off after a weekend of diving. Also make sure any deep scratches into the paint get touched up especially after a hydro as they will need to remove the paint to stamp the cylinder.

With that said if you get them all hydro'd and vis you could probably sell the lot and get yourself two nice galvanized 100s.

 

[-JD-]

I am assuming you are talking about pairs of individual tanks, not twinsets.

I'm a long-torsoed 5' 9" (used to be almost 5' 11" but several squashed discs subtract up I guess) I have PST HP3500 100s & 120's. Of course I also dive AL80s on travel.

I don't find the 120's undiveable, but they are less comfortable than the 100s and rest on my butt, so I know it is there. However they are only 2" longer than the LP85s or AL80 so nothing crazy. Arguably helpful if you have floaty feet and not so good if foot heavy. There are times where the extra 20cuft of gas is worth the extra 7lbs of land weight to me, in the water it is very slightly different but not problematic. For me the 120's a a bit more of a challenge to carry on land - with one in each hand, they just skim the ground. But I have longer arms - this is a personal geometry issue.

The 120s vs. your 85 will require one pound less lead for empty (safety-stop) weighting but are almost 4lbs more negative at the start of the dive. Consider your ability to get up if you have a BCD failure early in the dive, especially if you are diving deep and wet due to loss of buoyancy from suit compression.

7/8" necks aren't a problem if you are OK with 300Bar DIN only. Less options than with 3/4" for valves, but doable.

• The slant-back Genesis valves are really only an issue if the main-body or stems are damaged. Otherwise parts are available through Northeast Scuba Supply: (Genesis valve Parts)
• Piranha now sells Blue Steel 7/8" modular valves, including a full manifold if you want to double them: (https://www.piranhadivemfg.com/item/78-Hp-Din-Threaded-Rightside-Modular-Valve-16062 , https://www.piranhadivemfg.com/item/78-Hp-Din-Threaded-Leftside-Modular-Valve-16063 , https://www.piranhadivemfg.com/item/78-Hp-Din-Threaded-Complete-Manifold--16064)

One consideration is simple gas capacity. The 120s give you more options including longer/deeper or even 2-dives per tank for short/shallow.

Here are some comparison figures on the tanks for you.

In the end. Dive them both and see which feels better for you. Balance that with the other factors and then decide.