PDA

View Full Version : Tanks bouyancy?



Scotttyd
05-23-2008, 05:32
In the past I have seen a chart that compares the dimensions, buoyancy, and weights of different size tanks, does anyone have that by chance? Basically I am looking at the buoyancy differences between a HP 130 and AL 80 to help calculate my weight for an upcomming trip. If I remember right a HP 130 is about 6 lbs more negative.

BouzoukiJoe A.K.A. wrecker130 AKA Chuck Norris AKA joeforbroke (banned)
05-23-2008, 05:45
There a chart in the cylinders section at techdivinglimited.com.

I've seen you use the 130 at the quarry, so if you are using the same exposure protection and other gear add some weight for the change to salt water. For me, I add 7 pounds. Smaller people would add a little less. Since you'll be diving deeper, make sure you have enough weight to hold your stop. I don't think sinking will be a problem with that tank.

Bigg_Budd
05-23-2008, 06:16
HP Steel 130 Scuba Tank High Pressure X8-130, Scuba Tanks, Worthington, HP Steel 130 Scuba Tank High Pressure X8-130 (http://www.scubatoys.com/store/detail.asp?product_id=X8130)

Bryanmc
05-23-2008, 06:54
Here's the chart I use.

http://www.huronscuba.com/equipment/scubaCylinderSpecification.html

Charles R
05-23-2008, 07:57
Here's the chart I use.

http://www.huronscuba.com/equipment/scubaCylinderSpecification.html

That one cover them all. Thanks for that.:smiley20:

cmburch
05-23-2008, 09:41
My HP130s are about -2lbs empty.
http://www.xsscuba.com/tank_steel_specs.html

RoyN
05-23-2008, 12:39
Here's the chart I use.

http://www.huronscuba.com/equipment/scubaCylinderSpecification.html


Is it just me or the Fabers HP100 I'm using is really heavy...:smiley29: 7 lbs empty

Charles R
05-23-2008, 12:56
They are really heavy but on the bright side they will work great with you new dry suit!:smiley20:

RoyN
05-23-2008, 13:08
I'm not wearing any weights when I'm diving in my 7mm wetsuit. Can't wait for the new drysuit, it has just shipped so I'm happy :D

cummings66
05-23-2008, 13:33
7 lbs negative empty, yes that's heavy. Now I see why you've had issues with weighting. Mine are near neutral empty, the old PST's really are a fantastic cylinder when you look at their specs compared to some of the newer cylinders.

Not all cylinders as the charts mentioned above show are that heavy empty, I didn't seem to recall the Fabers being that way but I'll take your word they are. I have seen others that were.

CompuDude
05-23-2008, 15:10
Here's the chart I use.

http://www.huronscuba.com/equipment/scubaCylinderSpecification.html


Is it just me or the Fabers HP100 I'm using is really heavy...:smiley29: 7 lbs empty

Faber makes several models of HP100. The FX100 tanks that I use are only -1 lb empty, which is closer to most other tanks. They have several lines of tank, however, including some really heavy ones. Those heavy tanks are popular in some places, and rarely seen in others... I'm not sure why. I prefer tanks in the -1 to -2.5 range, from a buoyancy perspective.

The chart I use for most quick checks is the TechDivingLimited chart, which can be found here: Scuba Cylinder Specifications from Tech Diving Limited - 928-855-9400 (http://tdl.divebiz.net/pub/tanks.html)

Honestly, though, tanks change specifications from time to time, so it's often best to double-check the quick reference chart against the manufacturer's charts (see xsscuba.com for Worthingtons, divefaber.com for Fabers, or catalinacylinders.com or luxfercylinders.com for Catalina or Luxfer aluminums)

Splitlip
05-23-2008, 15:32
TECHDIVINGLIMITED.COM (http://www.techdivinglimited.com/)

click link to cylinders then link to spec page

Never mind :)

ChrisA
05-23-2008, 15:59
In the past I have seen a chart that compares the dimensions, buoyancy, and weights of different size tanks, does anyone have that by chance? Basically I am looking at the buoyancy differences between a HP 130 and AL 80 to help calculate my weight for an upcomming trip. If I remember right a HP 130 is about 6 lbs more negative.

Look it up if you like but no need to, 6 lbs is the right answer.

But note that you will be heavy at the beginnig simply becasue 130 cu ft of air weighs more than 80 cu ft. You'll have a couple pound "extra" on at the start, but it's at the end that maters. Almost all of the modern 3440 psi tanks are about -2 when empty and the AL80 is about +5 Don't forget about trim. the steel tanks adds it's extra weight at the middel of your back

Scotttyd
05-23-2008, 16:29
There a chart in the cylinders section at techdivinglimited.com.

I've seen you use the 130 at the quarry, so if you are using the same exposure protection and other gear add some weight for the change to salt water. For me, I add 7 pounds. Smaller people would add a little less. Since you'll be diving deeper, make sure you have enough weight to hold your stop. I don't think sinking will be a problem with that tank.

Actually I am loosing the 3mm shorty and just have the full and hooded/vest. In Hawaii I dove with an AL100 and had 20 lbs (3mm full), although I am unsure of it was a catalina or Luxer (3 lb difference). Although that chart states the working pressure is 3300, I only had 3000, I realize now I was jipped 300 psi. Last time at the quarry I had 11 lbs and a primary light (without the shorty) and was slightly heavy but ended with 1100 psi. I will add a reel and the SMB, I am thinking 17 lbs should be good?