Faber Fx tanks vs Faber HP tanks

[Brian Sharpe]

Ok, maybe my brain isn't at its best post holidays but........

If you compare the specs for a Faber HP100 and FX100DVB you get:

# DIAMETER: 7.2 inches / 7.24
# LENGTH: 24.2 inches / 25.39
# WEIGHT EMPTY: 38.7 lbs / 34.3
# BUOYANCY FULL: -14.11 lbs / -8.41
# BUOYANCY EMPTY: -6.69 lbs / -.0.16

would it be reasonable to conclude that the Fx is, in some respect, of lower quality/durability than the standard HP100? (Thicker steel?)

They both seem to sell for pretty much the same price, and I'm assuming all other things being equal any weight you save on the tank will end up on your belt (at 5'10", 225 I'm pretty buoyant) is there any reason I'd pick one over the other?

 

[wxboy911]

I dive a Faber100 mid pressure(3180 +10%) and I love it. When I am in the 7mm wetsuit I take 10lbs of lead. If I am diving an AL80 its 22lbs of lead. I picked the mid pressure tank so I could drop lead...I picked the 100 for the extra air and my total weight on my way to the water is less than what I would carry if I were diving an AL80. If you can get a mid pressure tank for the same price as an HP I would go for it. I have taken that tank to the pool and without the wetsuit I sink like a stone so it may not be a warm water tank.

 

[Puffer Fish]

Ok, maybe my brain isn't at its best post holidays but........

If you compare the specs for a Faber HP100 and FX100DVB you get:

# DIAMETER: 7.2 inches / 7.24
# LENGTH: 24.2 inches / 25.39
# WEIGHT EMPTY: 38.7 lbs / 34.3
# BUOYANCY FULL: -14.11 lbs / -8.41
# BUOYANCY EMPTY: -6.69 lbs / -.0.16

would it be reasonable to conclude that the Fx is, in some respect, of lower quality/durability than the standard HP100? (Thicker steel?)

They both seem to sell for pretty much the same price, and I'm assuming all other things being equal any weight you save on the tank will end up on your belt (at 5'10", 225 I'm pretty buoyant) is there any reason I'd pick one over the other?

A bit confusing because they are not telling the whole story.

The FX series is chrome Moly steel, which is stronger, but costs more...the concept was to make tanks that when empty were as close to zero buoyancy as possible...

That is a huge issue with doubles, but can be an issue in warm water diving.. if one has a BC (or wing) failure.

Chrome Moly has some good and bad points... it expands and contracts more with temperature... so a hot fill = lower pressure when cooled. It tend to just surface rust...and in general is more rust resistant..a good thing.

I dive in warm and cold wate... and only own the FX series...but if you dive only cold water, the HP's might be better (as long as not doubled).

 

[halocline]

would it be reasonable to conclude that the Fx is, in some respect, of lower quality/durability than the standard HP100? (Thicker steel?)

I would guess no. The only way you could determine this would be to have a database to see if there is any trend with either tank in failing hydro. The FX tank is a special permit tank, I guess it's theoretically possible that the permit will expire someday and not be renewed. I have one and I like it very much except for the dumb "blue steel" writing on it.

To me, a tank that's 14lbs negative full has very limited use, but I'm a warm water diver.

 

[fnfalman]

The prices are about the same, so I doubt that any model is "better" than the other.

I like the heavy one (M-series) because between the tank and my SS backplate, while wearing 7mm wetsuit, I don't need any additional weight. I can go to the HP120 and the dive weight still remains the same.

 

[Leadking]

FX is a higher strength steel alloy that will allow thinner walls (3342 psi)
HP is the standard 3AA steel so the walls have to be strengthed (3180+psi)

Also be aware the because of the 3498 (3180x1.1) a 7/8 valve with 300 bar outlet is the only valve configuration for this cylinder while the FX uses the standard 3/4x14 thread.

 

[tech3324]

FX is a higher strength steel alloy that will allow thinner walls (3342 psi)
HP is the standard 3AA steel so the walls have to be strengthed (3180+psi)

Also be aware the because of the 3498 (3180x1.1) a 7/8 valve with 300 bar outlet is the only valve configuration for this cylinder while the FX uses the standard 3/4x14 thread.

I'm confused about this. It says that a Faber 3180 would take a 7/8" valve which seems to contradict what I read here: SCUBA Valves: Regulator Fittings, 200 vs 300 Bar FAQ and Cylinder Neck Threads - Dive Gear Express which says,

"So how do you figure out what you have? Look at the SCUBA Tank neck for the DOT stamp. If it reads DOT-3AL or DOT-3AA it has a 3/4 NPS threaded neck opening. (3AL means aluminum, 3AA means steel.) "

What I'm trying to determine is the neck threading on a Faber medium pressure (3180+) steel 100 (3AA). Any clarification would be appreciated.

 

[Leadking]

the plus rating of 3180 is 3498, which most call a 3500 cylinder. You have 7/8" threads

 

[tech3324]

the plus rating of 3180 is 3498, which most call a 3500 cylinder. You have 7/8" threads

Thanks. I'm still confused though. Just found the Faber site and for the 3498psi steel tanks it says "Inlet Thread 3/4" - 14 NPSM". Cylinder Specifications bottom of the page, model "M100DVB".

 

[rjack321]

The 3180psi+ cylinder is a 3AA cylinder with a 3/4" neck. (The 7/8" neck size was only used historically by PST when they made 3500psi exemption series tanks. 7/8" is actually a physically smaller opening, go figure.)

The Fx is an exemption series tank. Need an additional special hydro step to pass.

The "Hp" is a 3AA tank and is tested to a different standard. It takes more steel to meet that standard so its heavier and more negative. One is not "higher quality" than the other, they are just made to different DOT standards for different purposes.

The Hp tank is popular with drysuit divers using single tanks. It won't work for doubles. The Fx series is popular as a single tank or doubled up.