Thinking about a Worthington X7 - 100 HP

[st1650]

Okay well I'm 6'4 ~ 240 lbs and my air consumption isnt very good so I think I should increase my air availability by going to something bigger than AL80. The X7 - 100 is on sale at my LDS and well it looks like it's the best all-around tank for a single rig. How much more capacity I get switching from AL80 to HP100 ? Is it worth the price?

Also I dive with a DSS BP/W with 8lbs weight plates and 7mm wetsuit, am I going to be too overweighted ? Should I get rid of the weight plates when I dive on steel and put them back when I dive on rental AL80?

Thank
Eric

 

[CompuDude]

Look at my recent thread re "steel tanks: math!". Worthington HP 100s have very similar weight characteristics to the PST HP 100s. They're both great tanks, nearly ideal IMO.

Going from an alum.80 to a PST (or Worthington) HP100 to an Al.80, you'll want to drop about 5-6 pounds. Keep the weights handy for when you rent the Al.80s.

 

[The Kraken]

Well the buoyancy difference between the two tanks, empty, is 5 pounds.

The 100 will be -1 pound and the Al80 will be +4.

So that means, all other things being equal, that you will be able to drop 5 pounds from your required weight and still maintain neutral buoyancy on a safety stop.

The tanks are almost identical in empty weight. The experienced weight on land will be what ever the weight of 23 cubic feet of air weighs minus the 5 pounds that you drop from your belt.

So I'm guessing that it would, for the most part, be a lateral move with respect to buoyancy.
the K

 

[c555]

I have the X7- 100's and they are great. I dropped 5 pounds and have longer bottom times, so I think it is worth it.

 

[DivesWithTurtles]

Per the specs:
The Worthington X7-100 is 2.5 lbs. neg. empty.
The PST E-7 100 is 1.3 lbs. neg. empty.
Individual tanks will vary slightly, but not much.

 

[spectrum]

It's a nice way to dive. My E-7 80s are usually more than enough. I do have a pair of the older 3500 PST HP 100s that have very similar properties to the newer 3442 PSI cylinders and they are nice. I can sometimes make 2 dives on on cylinder.

Pete

 

[riguerin]

Okay well I'm 6'4 ~ 240 lbs and my air consumption isnt very good so I think I should increase my air availability by going to something bigger than AL80. The X7 - 100 is on sale at my LDS and well it looks like it's the best all-around tank for a single rig. How much more capacity I get switching from AL80 to HP100 ? Is it worth the price?

Also I dive with a DSS BP/W with 8lbs weight plates and 7mm wetsuit, am I going to be too overweighted ? Should I get rid of the weight plates when I dive on steel and put them back when I dive on rental AL80?

Thank
Eric

Hey Eric,

I own an X7-100. It’s a great tank for the price.

This stuff has been covered all over SB. However, as you undoubtedly already may know, you can potentially have up 22.6 cuft more gas in the X7-100 versus an AL80 … assuming that both are filled to their service pressure. This is 3442 psi @70F for the X7-100 compared to 3000 psi for an AL80.

Even if you get shorted on fills, you will always have more volume of air in the X7-100 than with an AL80 at comparable pressures. For example, assume both are filled to 3000psi

X7-100 : 3000 psi * (100 cuft / 3442 psi) = 87.2 cuft
AL80 : 3000 psi * (77.4 cuft / 3000 psi) = 77.4 cuft (NOTE: AL80 contains 77.4cuft at rated service press)

Here’s a little tank volume calculator that will allow you to play around with other scenarios.

As far as weighting goes, other's have already pointed out that buoyancy characteristic of the two tanks are quite different. You will need to adjust your weighting accordingly. The X7-100 has a buoyancy of -2.5lbs when empty, compared to around +4 lbs for a typical AL80 when empty .... a difference 6.5 lbs. In actual practice, however, I found that I could eliminate 8lbs of weight when I switched to the X7-100. Check out this site for additional tank spec info.


Good luck !!!!

 

[Peter_C]

At your size you might even think about going up to a 120 cf. Maybe start a post with your stats in them and ask others, with more knowledge, which tanks they recommend for you. I have the X7 HP 100's and am very happy with them, and would say you can not go wrong with either size.

 

[st1650]

Whole post


Good luck !!!!

Sweet man nice post!

I'll definatly backup that!


Thanks a lot!

 

[mike_s]

so what are you folks seeing the HP100 from Worthing for at your LDS? ($$)