tank size

[barrmust]

I have looked through the past threads and didnt realy find the answer.
I am looking at buying steel tanks and have it narrowed down to 3. i am looking for opinions and why you think that. i am going to use the tanks for singles and independant twins. i am in maryland and am getting ready to buy a drysuit soon but will dive wet during the summer. my normal dive buddys have 100s and some 120s. i dont want to get a tank to small but dont want to go as large as a 120 steel.

my choices are:
lp-85 34 # 7.25 diameter 2640 psi $200
lp-95 37 # 8.0 diameter 2640 psi $245
fx-100 34 # 7.25 diameter 3442 psi $270

with the lp tanks i wont have low fill issues and have the option of overfilling them.
the 3442 tank wont ever fail to get a + rating but also no overfills. also i am looking to buy 3 so price is somewhat of an issue.

Russ

 

[Tagerisatroll]

The biggest issue you will run into is the length of the tank, if your a tall person, like me I'm 6' 4" a LP tank will be nicely balanced and you won't really notice how long the tank is, but if your shorter it will feel like you are knocking your head, and have a tailer because the LP tanks are taller than the HP tanks.

 

[merxlin]

Actually an LP 108 is 26", an AL80 is 25.8". The LP's are an 8" diameter. heres a place you can compare- http://www.techdivinglimited.com/pub/tanks.html . I just had a similar thread, and after all the good advise decided on an LP108. Heres the thread: http://www.scubaboard.com/showthread.php?t=173640

 

[Otto]

You didn't say how you were going to use the independent twins. If side mount, the length is not a big issue. The Faber LP 85's are the same size (length) as Aluminum 80's (really 77's) and neutral boyancy with more air.

 

[spectrum]

I have looked through the past threads and didnt realy find the answer.
I am looking at buying steel tanks and have it narrowed down to 3. i am looking for opinions and why you think that. i am going to use the tanks for singles and independant twins. i am in maryland and am getting ready to buy a drysuit soon but will dive wet during the summer. my normal dive buddys have 100s and some 120s. i dont want to get a tank to small but dont want to go as large as a 120 steel.

my choices are:
lp-85 34 # 7.25 diameter 2640 psi $200
lp-95 37 # 8.0 diameter 2640 psi $245
fx-100 34 # 7.25 diameter 3442 psi $270

with the lp tanks i wont have low fill issues and have the option of overfilling them.
the 3442 tank wont ever fail to get a + rating but also no overfills. also i am looking to buy 3 so price is somewhat of an issue.

Russ

I wouldn't get to hung up on the + rating. If you don't abuse the cylinders you will probably maintain the + for as long as you are diving, given a good hydro station. Meanwhile HP cylinders have been known to fail and be condemned though it's sometimes through the fault of an inept hydro operator. Either way you have a minor exposure.

As practical measured look at size, weight and capacity.

Bounce capacity against your air usage. If you seek to match divers using 100 and 120 CF cylinders does you usage rate allow you drop to a supply less than 100CF? You mention diving with an overfill. The availability of going beyond the +10% value varies.

How will the larger LP cylinders rest on your body in terms of fit?

Where are you strength wise? Moving to a drysuit usually entails more weight and how much will that add up to with a LP cylinder? Is this a concern? If so it's a point for the HP cylinder. Depending on specifics the LP cylinder will off set more lead than the HP model. Compare the empty buoyancy specs for the numbers: http://www.techdivinglimited.com/pub/tanks.html
You can also use data from your planned seller.

Don't forget your regulator. Is it OK going to 3442+? Most are but it's a question that needs an answer. This leads to your yoke. With the HP cylinder many of us consider a DIN connection desirable. How do you feel about this, what is involved in converting your regulator and how does this play with other cylinders you may have? With LP this paragraph goes away.

As for doubling up I'm not the one to comment.

Pete

 

[idive2]

my choices are:
lp-85 34 # 7.25 diameter 2640 psi $200
lp-95 37 # 8.0 diameter 2640 psi $245
fx-100 34 # 7.25 diameter 3442 psi $270

I'm leaning toward an LP for my second steel tank. I think the LP85 is
a 7 " diameter tank, I really wanted the LP85 but want to stay with the 7.25"
dia. as my HP100 and AL80s are all 7.25. I don't want to have to adjust my
tank strap when switching tanks. I see PST has a galvanized LP80 with a 7.25"
dia. just not sure with all this exemption stuff going on with PST if I want to go that
way or not. Good luck with your choice and I think steel tanks are a good bet and the LP tanks seem to be coming back into popularity or maybe they never went out !

 

[divinginn]

my biggest prob with lp tanks is keeping +ratings on the tanks,just finding someone to do a plus rating is very difficult,so i went with a hp 100 to replace the steel 65s,some call them 72s,love the steel 100,plenty of gas and about the same size as the 65s.

 

[rjack321]

All modern/new LP tanks are marked with an REE (reject elastic expansion) number on them. Even if the fire extinguisher shop has NEVER done a scuba tank before they can easily compare the measure expansion to the REE and plus rate a tank.

If they can't even do this, get another hydro shop.

 

[barrmust]

i am 5'11 so a shorter tank is better. i have used a 120 at 29' tall and it was to tall for me. the 3 tanks i listed are all around the size of an aluminum 80 or slightly shorter. tank diameter is not really an issue as i am going to buy 3-4 tanks so i will always be using the same size. i am a pretty big/strong guy so the weight of the tanks and dry suit is not much of an issue. the lp-85s weigh 3 pounds more than an aluminum 80 and the 95s are 7 pounds more. so worse case i am looking at 14 pound more with twins. when using them as twins they are backmounted. i have been using aluminum 80s as twins already and dont find them to heavy. we have a local dive shop that does hydros in house and will do + ratings so that is a non issue. i am leaning towards the lp-95s. i guess it boils down to is it worth the extra $50 per tank for the slightly bigger size. thanks for your responces.

Russ

 

[TASea]

with the lp tanks i wont have low fill issues and have the option of overfilling them.
the 3442 tank wont ever fail to get a + rating but also no overfills. also i am looking to buy 3 so price is somewhat of an issue.

Russ

I own LP95's and HP130's, and at most of my LDS's it's usually equally difficult to get good fills (rated pressure when cold) on either of them. Then there's one LDS who will fill my 130's up to 4000 psi if I want (I don't!), but it's all I can do to get him to fill my 95's to 2640 psi. Unless you already know your LDS will fill the way you want, I wouldn't take it as a given that you won't have low fill issues (or get overfills) with LP tanks. At least with the bigger HP tanks if you get short filled you've still got a lot of air.