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limeyx · April 23rd, 2008, 04:48 PM

Quote: (Originally Posted by David Martin)

Can someone let me know what the buoyancy characteristic of the US 104s and/or 120s are? Either with or without valve/bands (just say which). Or what the mass of the steel and the internal volume is, so that I can work it out.

I've dived 104s a couple of years ago and although I remember they were noticeably heavier than the 12s we use in the UK I don't know by how much. I know I was overweighted with a Pro-14 an alu backplate and no lead; however when I go back I'll have noticeably newer (and hence more buoyant) undersuit and a 9Ah canister. It would be good to know whether I should be taking a steel or an alu plate with me.

David

It depends on the manufacturer somewhat.

This list is a good start
TECHDIVINGLIMITED.COM

The PST 104 is -3.3 pounds empty with valve according to that table.
And the PST HP120 is neutral when empty

However, there are different manufacturers of those tanks which can be far more negative empty.

According to this chart ....

XS Scuba Worthington Steel Cylinder Specifications

The HP130's (which I think are approx the size of 104's) are 16L tanks and HP119/120 are basically 15L's

These tanks are heavy full, but their empty buoyancy is such that for me with a 400G and no heavy light, I still need quite a bit of lead to sink them when they are empty.

April 23rd, 2008, 04:48 PM	#7 (permalink)
limeyx(Offline) New Member Join Date: Nov 2005 Location: Los Angeles, CA Posts: 736	Quote: (Originally Posted by David Martin) Can someone let me know what the buoyancy characteristic of the US 104s and/or 120s are? Either with or without valve/bands (just say which). Or what the mass of the steel and the internal volume is, so that I can work it out. I've dived 104s a couple of years ago and although I remember they were noticeably heavier than the 12s we use in the UK I don't know by how much. I know I was overweighted with a Pro-14 an alu backplate and no lead; however when I go back I'll have noticeably newer (and hence more buoyant) undersuit and a 9Ah canister. It would be good to know whether I should be taking a steel or an alu plate with me. David It depends on the manufacturer somewhat. This list is a good start TECHDIVINGLIMITED.COM The PST 104 is -3.3 pounds empty with valve according to that table. And the PST HP120 is neutral when empty However, there are different manufacturers of those tanks which can be far more negative empty. According to this chart .... XS Scuba Worthington Steel Cylinder Specifications The HP130's (which I think are approx the size of 104's) are 16L tanks and HP119/120 are basically 15L's These tanks are heavy full, but their empty buoyancy is such that for me with a 400G and no heavy light, I still need quite a bit of lead to sink them when they are empty. __________________ my divelog: http://www.mydivinglife.com/limeyx