Pst E-7 120 = E-8 149

[Uncle Pug]

jonnythan once bubbled...
Do you?

My Rix is set to shut off at 3700... and the only time my 104s see that is when I forget them online while filling the bank. I consider 3000 a respectable fill for two dives.

 

[The Fresh Prince]

Have already filled past 3500 on my LP104's at least one hundred times. No problems and they usually cool down to 3500 at the start of the dive. Fortunately, most shops around here have tech/cave divers on staff and are not afraid of their own shadow.

 

[Warren_L]

I think I read somewhere that during burst testing, the cylinders that are sacrificed are pressurized over 2 times their service pressure without failure. Wouldn't want to be around when one of those blows.....

Dive4Life - the E7-120 and E8-119 are both HP tanks. The 120 has a slightly higher water capacity but is actually almost 3 lbs lighter than the 119.

 

[nyresq]

OMS states their tanks have a service life of 10,000 fills at 4000psi... so you can fill them 10,000 times to 4,000psi before they blow.. in theory...
I changed the burst disks for 3500 svc pressure in all my LP tanks and I fill to 3600psi for deep dives with out even breaking a sweat.... but 4,000 eh, I'll leave a little safety factor in there...

I also fill mine in a bomb proof fill station with 1/2" plate steel btw me and the tank... in a fire station... with plenty of EMTs around....

 

[Uncle Pug]

nyresq once bubbled...
with plenty of EMTs around

 

[bg10459]

I have already had it filled that high once before.

I'm new to diving and by no means an expert. I too am looking at the e8-149. An e8-149 is an lp-120 rated for 3442. PST may have added more steel to the new tanks to help the rating, not sure. I wouldn't over fill an lp tank though, thats why you buy them, to reduce operating stress on tanks, and regs too. It would probably hold the pressure without a problem, but think about the long term effects. I want the 149 because I can run it at lower pressure for reduced stress on my gear and in anticipation of the underfill I'm sure to get, and still have lots of air. Then I can bump it up safely when needed.

 

[pescador775]

The LP's are actually rated 2475 so a 2600 fill is already 'overpressure'. somebody at PST thought the same thing as some of the techies, 'hey, the techies are overfilling these things, why can't we just rebrand the 'LP' as an E7 or E8?' So solly charley, no tickee no laundly. The carbon steel tank just couldn't meet the spec so they rebranded the old HP tanks instead. Instead of overfilling a LP tank they give you the option of filling a REAL HP tank to 3500, or 4000 if you must. They wanted to dodge the restictive EU rules about neck size so they came in at 3442, just under the arbitrary and obsolete 3500 limit.

I have already had it filled that high once before. My first fill actually. The LDS's in Miami, especially those cadering to techies don't have a problem over filling. I don't want 150 cu.ft of gas trying to escape on me to quickly though. After reading some of the posts around here I have to admit I am getting a bit nervous about it. I appreciate the feedback, lets just hope my tank doesn't decide to go boom anytime soon. I bet that would destroy a room or a vehicle.

 

[pescador775]

The E series tanks use high tech steel to obtain the high service pressures; the thickness is less than some other brands and the tanks themselves are quite light for their capacity. Some tech divers like the somewhat heavier LP tanks for balance or whatever. An E8149 is equivalent in capacity to a set of double tanks of normal size (double 72's). I've met some really big divers who use a LOT of air, newbies mostly but I'm not sure that experience changes air consumption much. It happens but I wouldn't make any assumptions. To make two no-deco dives to, say, 60 feet most divers would need double 90's. This gives a bit of margin, just a bit. I would say that the 149 falls into a nether zone. For a person of your size it falls into the category of one dive with 10 minute stop plus enough air left over to be designated as the grapple puller at the end of the day. Don't count on it for two working dives unless your air consumption is less than average or your work profile is sedentary, for example a photog sitting on the bottom for extended periods.

I have already had it filled that high once before.

I'm new to diving and by no means an expert. I too am looking at the e8-149. An e8-149 is an lp-120 rated for 3442. PST may have added more steel to the new tanks to help the rating, not sure. I wouldn't over fill an lp tank though, thats why you buy them, to reduce operating stress on tanks, and regs too. It would probably hold the pressure without a problem, but think about the long term effects. I want the 149 because I can run it at lower pressure for reduced stress on my gear and in anticipation of the underfill I'm sure to get, and still have lots of air. Then I can bump it up safely when needed.

 

[drbill]

I had a PST HP120. Although not usually filled beyond 3700 psi, it received a number of hot fills from a local LDS. It seriously failed hydro (> 16% expansion) after just 10 years. Grrr. I certainly don't recommend "overfilling" of anything other than a + rated tank (in which case you're not really overfillling it). Watch out for those repeated hot fills too.

Dr. Bill

 

[pescador775]

I've seen PST tanks fail for no obvious reason. I believe that there are manufacturing variations in some of their product lines. I returned a 3000 + (old style) tank which had failed and showed no obvious damage such as heat or pitting. It had never been overfilled. After some months, PST said that they lost it (!) and replaced it with a new HP 100. Hmmmmm, "lost".... Yep.

I had a PST HP120. Although not usually filled beyond 3700 psi, it received a number of hot fills from a local LDS. It seriously failed hydro (> 16% expansion) after just 10 years. Grrr. I certainly don't recommend "overfilling" of anything other than a + rated tank (in which case you're not really overfillling it). Watch out for those repeated hot fills too.

Dr. Bill