Faber Tank Purchase -- Weight is off, what am I missing?

[Schwob]

As suggested above, if I bought that tank specifically for the light weight, I'd weigh it with the boot and valve taken off ... and would do so on a known accurate scale in that weight range (a shipping scale, maybe at the UPS store or post office?). Anyway, if valve and boot were to amount to 3 lbs together (I don't know that am repeating a stipulation above) and if your 31.1 lbs weighing is accurate, then the tank would be close to 13% over the quoted weight. Sure the process varies, but I would be hard pressed (ha!)in understanding how the blanks used for pressing (or the small amount of machining involved) could vary that much.
Either way, if you do weigh the tank w/o valve and boot, please do post your result.

 

[almostDIR]

they are pressed from a blank to an open cylinder shape and then the shoulder and neck portion is made by hot spinning process and further machining. I assume the variations could be mainly due to that neck portion process and the trimming stage and the original blanks would be very constant quality.

fascinating process btw

 

[certainmisuse]

Update:

So I took the boot off and measured weight, length and diameter. The weight is now 30 lbs; I should have mentioned the original weight was more like 31.5 lbs. So the boot appears to be 1.5 lbs. We also believe the scale could be 0.5 lbs heavy, so this suggests the tank plus value is 29.5 pounds, which of course is 4.8 lbs from the manufacturers number of 24.7 lbs. While I still don't believe the valve weighs that amount, both the diameter and length were off enough to believe the variance argument. The diameter measured larger by fractions of an inch and the length measured short by fractions of an inch. This weekend I plan to get the tank filled after which I will remeasure the weight. Also worth nothing, little air escaped for the last two times I opened the valve.

Can anyone comment on why the fill pressure stamped on the tank says 3000 psi and not the 3400 psi as indicated in the table? I figured there would be an indication if overfill was allowed. In fact it states, "do not overfill". Thanks for any info.

Cheers.

David

 

[shoredivr]

I wish Worthington was still making scuba tanks. I like them way better than Fabers.

 

[Landau]

What are the exact markings on the tank? Could it be an M71DVB which matches " diameter measured larger by fractions of an inch and the length measured short by fractions of an inch." and 4 pounds heavier than the FX71DVB you ordered?

see: Blue Steel Scuba - Cylinder Specs

 

[JackD342]

What are the exact markings on the tank? Could it be an M71DVB which matches " diameter measured larger by fractions of an inch and the length measured short by fractions of an inch." and 4 pounds heavier than the FX71DVB you ordered?

see: Blue Steel Scuba - Cylinder Specs

You beat me to it. That is almost for sure the answer, it explains everything.

Does it say DOT-3AA, or DOT-SP13488?

 

[Newdiv]

 

[Newdiv]

Both of the previous post beat me

 

[JackD342]

In fact it states, "do not overfill". Thanks for any info.

Where did you see that? I don’t think have ever seen anything like that on cylinder markings. Or is it on a long wordy adhesive label?

 

[Snoweman]

I wish Worthington was still making scuba tanks. I like them way better than Fabers.

I am completely ignorant about tank construction (other than watching the video). What makes one better than the other?