Bad tank purchase?

[Roman_66]

Hi,
Just received today "SHERWOOD HP 120", which actually arrived with stamp Scubadist.com ST 120 on it.
I am pretty big (fat) and use more gas than average diver. To be able to join to dive group, I decided to buy bigger tank.
Due the fact that I not wear weight belt, I am limited with weights, which I can take.
6 (Halcyon backplate) + 1 (adapter to one tank) + 2 x 5lb in Halcyon ABC pockets + 2 x 3 (trim pockets on tank adapter) = 23 lb.
In salt water I need about 30 lb (dry suite with Xerotherm and hood).
According to specification on site "HP120 BUOYANCY WITH 500 PSI: -4.6lbs" against empty Luxfer LAL80 +3.4 lb
So I won more than 7lb, exactly that was needed !
Topic started mentioned issue with "dot sp12079".
The document says Expiration Date: December 31, 2017.
Does it mean that I bought new tank for three years only? I am new in US and not familiar with DOT special permits meaning.
I didn't find any better option to buy 120 cf (15 liters) steel in US.
Sherwood and Worthington stopped steel production lines and you can find them only in few shops having it on stock.
Actually I planned to buy Worthington X7-120, but was not able to find it.
Faber is not option for me due FX120DVB is positive at the end.
"SHERWOOD HP 120" has Inlet thread standard 3/4"-14 UNF-2B.
DIN/Yoke valve has mark "H" (not Halcyon ) on one side and 13/06 on other, looks like noname brand.
I am not able to untwist middle part to make it DIN. Is it opposite way thread ?
Not sure how to check that valve is DIN 200 and not 300.
Unfortunately my "dream" cylinder for single and double doesn't have DOT and not imported to US.
Any other suggestion for big steel tank ?

I think Faber HP100 is -7.26lb empty, or are we talking about the same Faber?

Depends.... : old Faber M100DVB -14.11/-6.69, but new Faber FX100DVB -8.41/-0.59

 

[kwinter]

Don't worry. The special permit will almost certainly be renewed in 2017. That tank will be good for many many years.


iPhone. iTypo. iApologize.

 

[Oldbear]

No worries...there is always a good use for any tank...

 

[WestCoastDivr]

Thanks for the input everyone, with all the speculation about weight it looks like I'll just have to try it out. I should have the money for a manifold, bands, and a doubles wing in a month or so and I will update the thread if anyone is curious to how they work out


Sent from my iPhone using Tapatalk

 

[Roman_66]

Small question regarding Valve, just to not open new topic.
With my Sherwood 120 come Harrison Valve.
Specification says Service pressure : 3000 PSI, but tank I think 3442. Should I specify every gas filling that maximum pressure - 3000 ?
In valve specification Nitrox compatability up to 40% isn't mentioned. Should I ask to replace the valve or it is not important for valves ?

 

[TheRealScubaSteve]

Should I ask to replace the valve or it is not important for valves ?

My experience with Harrison pro valves is that they are utter garbage. They look like they were molded in a sandbox and, as a result, o-rings tend to fit too loose. They seal just fine when your 1st stage is attached, but the loose allows o-rings to fall out much too frequently. I'd upgrade them just to get better valves, but if you are not inclined to do so, they'll work just fine. Keep in mind that my experience is with yoke only - din may not be as much of an issue.

 

[WestCoastDivr]

Small question regarding Valve, just to not open new topic.
With my Sherwood 120 come Harrison Valve.
Specification says Service pressure : 3000 PSI, but tank I think 3442. Should I specify every gas filling that maximum pressure - 3000 ?
In valve specification Nitrox compatability up to 40% isn't mentioned. Should I ask to replace the valve or it is not important for valves ?

I've been using the HP sherwoods with the crappy Harrison valves with my DIN regs and a 5250 psi burst disk. I regularly fill the tanks to around 3600 PSI and have had no issue. Every LDS I've taken it to has had no problem filling it to that pressure either. Soon I'm upgrading to them being doubles with a manifold but for now the Harrison valve will do

 

[Scared Silly]

My experience with Harrison pro valves is that they look like they were molded in a sandbox.

While you were being sarcastic you are actually more or less correct. Many (most ?) valves are produced via sand casting. They are then machine finished. Obviously the finishing can be done differently.

OT But recently I was reminded about the Soviet era Mig-25 which the USA thought was one of the most advanced fighter jets at the time. That is until a pilot defected and they got a good look at the plane. Much to everyone surprise part of the superstructure was cast and never cleaned up as they found embedded sand. The avionics left a lot to be desired as well.