fun2chase
Contributor
Has anyone been diving hp steel 80's as doubles? What are the pros and cons?
Thanks,
-stacy
Thanks,
-stacy
Doubles
- Thread starter fun2chase
- Start date
Please register or login
Welcome to ScubaBoard, the world's largest scuba diving community. Registration is not required to read the forums, but we encourage you to join. Joining has its benefits and enables you to participate in the discussions.
Benefits of registering include
- Ability to post and comment on topics and discussions.
- A Free photo gallery to share your dive photos with the world.
- You can make this box go away
but the folks that like them seem to like the small size and the balance. The folks that don't like them seel to dislike the small size. I guess it depends upon what kind of diving you're doing and what how much gas you burn.
They're just cute as the dickens, though.
They're just cute as the dickens, though.
OP
fun2chase
Contributor
Since I am only 4' 10", the shorter tanks are probably going to be more comfortable. Will probably fill with Nitrox ~28% and may start cave diving (after taking the class of course)! Gotta love redundancy!
The Fresh Prince
Contributor
- Messages
- 168
- Reaction score
- 1
why not find a double set of LP 72's. Holds more gas and weighting is better.fun2chase:
WarmWaterDiver
Contributor
How do LP 72's hold more air than HP 80's? Are you "pumping" the 72's to some pressure above their stamp?jjsteffen:
Personally, I like my double HP 100's.
scubasean
Contributor
jjsteffen:
huh?
what am I missing here?
The 72's might hold more at their rated pressure than the hp 80's would at that same lower pressure(lower than the rated pressure for the 80's), but the 80's hold more at their own rated pressure as compared to the 72's at the rated pressure for the 72's...
Stacy,
Which tanks are best are going to depend on a number of factors, that not only include how comfortable they are for you out of the water but also how they trim you out IN the water! How much they hold may be moot, assuming that if you're considering two or three sets, they'll all hold roughly the same - within 14-20 cu ft. For example, consider these:
(new) HP Steel 72 Cu. Ft. mfg. by Faber 3300 Psi. ---- $208 + $25 s/h
diameter = 6.75" length = 20.5" weight = 28.7 lbs.
buoyancy in salt water empty = -3.7 full = -8.4
Note that these 72s are filled to 3300 psi, versus the lower 2640 psi tanks below.
The Fabers are normally available on this site here:
http://divesales.com/tanks/index.html
Compare with the OMS sets on this site here, particularly look at the C66:
http://www.omsdive.com/cylinder.html
The Faber 72s are 20.5 in length (height), whereas a set of the OMS C66 would stand 21 in height (length), both without valve measurements, per this page here:
http://www.omsdive.com/cyl_spec.html
Note how the OMS 85s are 26 in height. Thats actually quite a difference in terms of how they would feel to you and balance out (trim) in the water.
The PST E7-80 tanks would be 7.3 in diameter, a little larger but not the fat ones at 8, and are only 19.75 in height (length), making them the shortest of the three sets of doubles, per this site here:
http://www.lloydbaileysscuba.com/PST E Series Tanks.htm
While I'm partial to PST steels, Im of the opinion that you might want to take a look at a set of the older low pressure steel 72s. They are skinnier and a bit longer than 20", which can work out better for adjusting your trim, they are a tad lighter than the newer tanks, and best of all, you can find a set of them used with bands and manifold for around $300 and sometimes less depending on who you know!
The older LP steel 72s actually only hold 65 cu ft at their rated pressure, you have to fill them to their allowable 10% overfill to hit 72 cu ft. In a set of doubles, however, were talking a difference between the two of about 14 cu ft of gas, which assuming youre doing your gas planning properly is a negligible difference. In terms of cost efficiency, I think these would be your best bet if you can find a set of them. And being 4'10", I'll bet your SAC rate is much better than most of the people you're going to be diving with as buddies! A set of smaller doubles might be exactly what you will feel most comfortable with. (Have you ever looked at a set of aluminum 50s? I think they would also be perfect for you...)
Hope this helps,
Doc
Which tanks are best are going to depend on a number of factors, that not only include how comfortable they are for you out of the water but also how they trim you out IN the water! How much they hold may be moot, assuming that if you're considering two or three sets, they'll all hold roughly the same - within 14-20 cu ft. For example, consider these:
(new) HP Steel 72 Cu. Ft. mfg. by Faber 3300 Psi. ---- $208 + $25 s/h
diameter = 6.75" length = 20.5" weight = 28.7 lbs.
buoyancy in salt water empty = -3.7 full = -8.4
Note that these 72s are filled to 3300 psi, versus the lower 2640 psi tanks below.
The Fabers are normally available on this site here:
http://divesales.com/tanks/index.html
Compare with the OMS sets on this site here, particularly look at the C66:
http://www.omsdive.com/cylinder.html
The Faber 72s are 20.5 in length (height), whereas a set of the OMS C66 would stand 21 in height (length), both without valve measurements, per this page here:
http://www.omsdive.com/cyl_spec.html
Note how the OMS 85s are 26 in height. Thats actually quite a difference in terms of how they would feel to you and balance out (trim) in the water.
The PST E7-80 tanks would be 7.3 in diameter, a little larger but not the fat ones at 8, and are only 19.75 in height (length), making them the shortest of the three sets of doubles, per this site here:
http://www.lloydbaileysscuba.com/PST E Series Tanks.htm
While I'm partial to PST steels, Im of the opinion that you might want to take a look at a set of the older low pressure steel 72s. They are skinnier and a bit longer than 20", which can work out better for adjusting your trim, they are a tad lighter than the newer tanks, and best of all, you can find a set of them used with bands and manifold for around $300 and sometimes less depending on who you know!
The older LP steel 72s actually only hold 65 cu ft at their rated pressure, you have to fill them to their allowable 10% overfill to hit 72 cu ft. In a set of doubles, however, were talking a difference between the two of about 14 cu ft of gas, which assuming youre doing your gas planning properly is a negligible difference. In terms of cost efficiency, I think these would be your best bet if you can find a set of them. And being 4'10", I'll bet your SAC rate is much better than most of the people you're going to be diving with as buddies! A set of smaller doubles might be exactly what you will feel most comfortable with. (Have you ever looked at a set of aluminum 50s? I think they would also be perfect for you...)
Hope this helps,
Doc
OP
fun2chase
Contributor
Currently I am diving the LP steel 72's in a single configuration, so once I get a doubles wing, bands and manifold, I should be good to try double 72's. From what I understand, you have to have min 72 for the Intro to Cave class, so the aluminum 50's would not work. You are right, I can outbreathe most of the other people in the water. In fact, I usually end the dive due to cold rather than too little air! Since there is such an expense in buying tanks, I didn't want to purchase the steel 80's without some advice. I think I am going to try and find some to test in the water before I spend the cash. That of course may be tough to accomplish. Over time I will decide what is best. Can't do cavern or cave till I get better thermal protection anyway. That is going to be my next purchase before the tanks.
Thanks to everyone for their help!
Thanks to everyone for their help!
SouthFLdiver
Contributor
Stacy, do not buy faber or xs scuba tanks. Stick with OMS or PST, and I prefer low pressure, they hold a great deal of air. Go to the oms website and look at the design life of the lp steel cylinders; 10,000 cycles @ 4,000psi. LP is the way to go.
Similar threads
