Faber mid pressure 71?

[ndemeis]

Anyone dive this tank? Just came across it on scuba.com as i'm in the market for a tank now. Whats the cf like compared to other tanks? I'm not good with the conversions.

Also while i'm posting here I came across a post last year that detailed CF for tanks filled to different pressures IE the LP's as the 2400 and the 2600 pressures.

 

[Jim Lapenta]

A 71 cu ft tank has a capacity of 71 cu ft at rated pressure. Now to find out how much you actually have you need to know a couple things. One what is the rated pressure, is it 71 at rated plus 10% or 71 at rated. Once you know this you divide the capacity in this case 71 cu ft by the rated pressure. If it's 3000 the 71 divided by 3000 gives you .0236. Now take this times the actual pressure you put in and it will give you the volume of gas you have. For example you pump this 71 @ 3000 rated tank to 3500. Take 71/3000= .0236 x 3500 and you get the amount of air you have. In this case you now have 82.6 cuft of gas to work with. Hope that clears things up some. You should have covered this in your OW class. It's basic stuff. And the formula works for all cylinders. As to the 71 has a 5lb buoyancy swing- not bad but still ends up positive. and it rated at 3300 you may have trouble getting full fills at some of the more anal shops that will only pump to 3000 or so. It's also 341 bucks. Too much money for me. I'd consider the lp85 for 299. you'll always get good fills at it's 2640 rating and the buoyancy characteristics are much better. And if you pump it to 3000 or 3200 like I do you now have a 96.5 or a 103! A no brainer in my book as to which one to get. the 85 hands down.

 

[WD8CDH]

The M71DVB is actually a 3AA 3000psi tank with a +10% overfill to 3300psi to get 71cf. Depending on who does the hydro and the final results, you may lose the +10% rating and the tank would then be be only a 64.5CF tank.

I prefer the FX71DVB a little farther down the page. It is a 71cf tank at 3442psi and will always be a 71cf tank. It is also about 4 pounds lighter and has better buoyancy characteristics and is $20 cheaper. The FX71DVB is actually my favorite tank in the 60 to 75 cf range because of it's slim diameter.

Here is a thread on the FX71:
http://www.scubaboard.com/forums/tanks-valves-bands/290498-faber-fx-hp-71-a.html

The real question is whether a 71cf tank is the right capacity for you and your dive plan.

 

[Nemrod]

It is 71 cubic feet, that is 21 cf more than a 50 and about 6 cf less than an aluminum 80 (which are 77cf).

N

 

[Scared Silly]

My wife used these for doubles but then switched to LP66. They are not bad cylinders but at 3300psi they were odd birds.