Attention Steel Tank Dive Ops: HP Hot-Dipped Galvanized are back in production!

[scubafanatic]

Faber (with XS Scuba) has reintroduced HP Hot-Dipped Galvanized scuba tanks ! This is GREAT news for the steel tank ops who may want/need to replace their aging PST/Worthington HP tanks, and wish to avoid having to buy those delicate painted tanks.

In the USA, diverightinscuba has them for sale right now, divegearexpress will have them on safe soon, others undoubtedly will also be offering these new tanks.

 

[Jim Lapenta]

Hmm, if the HP tanks are anything like the LP's ops should think about replacing them when they are oh, 50 or 60 years old. My 72's from 53 and 54 passed hydro about a year ago.

 

[scubafanatic]

Hmm, if the HP tanks are anything like the LP's ops should think about replacing them when they are oh, 50 or 60 years old. My 72's from 53 and 54 passed hydro about a year ago.

Per Dave's (owner of Aldora) prior response to a thread I'd started a while back, his steel's only lasted about 5 yrs, (and expensive to import to Cozumel as well) and one motivation he had for running his own fill station was to stop his tanks from 'being beat to h*ll' by the island's central fill station, as the owner of his own tanks he can 'baby them', relatively speaking. Additionally, a warm, humid, constant salt-water environment is inherently 'abusive' for steel tanks. Given that hot-dipped galvanized is WAY superior to 'painted' tanks under such conditions, this IS good news!

 

[Dave Dillehay]

Dear Jim, it depends on how much you use them, and how you keep your workers and customers from abusing them. We've been using plastic tank protectors for some time now with the Fabers and without and significant difference from hot dipped galvanized from Worthington. BTW our tanks last about 3 years in continuous service—but lots of care taken.

For those who don't know the real advantage of HP 120/10 steel tanks in Cozumel, just know we spend about 50% more of our budget on tanks than do those operators who just use the aluminum 80s. There are good reasons.

Dave Dillehay
Aldora Divers

 

[BRT]

Dear Jim, it depends on how much you use them, and how you keep your workers and customers from abusing them. We've been using plastic tank protectors for some time now with the Fabers and without and significant difference from hot dipped galvanized from Worthington. BTW our tanks last about 3 years in continuous service—but lots of care taken.

For those who don't know the real advantage of HP 120/10 steel tanks in Cozumel, just know we spend about 50% more of our budget on tanks than do those operators who just use the aluminum 80s. There are good reasons.

Dave Dillehay
Aldora Divers

Why do they get taken out of service at about 3 years? Fail visual or fail hydro?

 

[DjDiverDan]

From what I have heard (and I'm certainly no expert), the years of use is less important to the useful life of a tank than the number of cycles - filling a tank up to full pressure, emptying it down to 500-700 psi, refilling it, etc., puts stress on the tank. Each full cycle results in some measurable flexing of the side walls, and the constant flexing back and forth is what causes the metal to weaken. Like airframes, it is the number of cycles on an airplane, taking off, pressurizing the cabin, landing and depressurizing, that governs when parts are required by the FAA to be inspected and replaced - it is the cycles, not the age of the plane, that causes flexing on all the metal parts which leads to metal fatigue. So for Dave to say that he only gets three years, if the tanks are used and refilled 6 times a week, that puts nearly 900 cycles on those tanks. I bet that's a lot more cycles than are ever put on a tank that someone owns and just uses maybe 8-10 days a year.

 

[scubafanatic]

From what I have heard (and I'm certainly no expert), the years of use is less important to the useful life of a tank than the number of cycles - filling a tank up to full pressure, emptying it down to 500-700 psi, refilling it, etc., puts stress on the tank. Each full cycle results in some measurable flexing of the side walls, and the constant flexing back and forth is what causes the metal to weaken. Like airframes, it is the number of cycles on an airplane, taking off, pressurizing the cabin, landing and depressurizing, that governs when parts are required by the FAA to be inspected and replaced - it is the cycles, not the age of the plane, that causes flexing on all the metal parts which leads to metal fatigue. So for Dave to say that he only gets three years, if the tanks are used and refilled 6 times a week, that puts nearly 900 cycles on those tanks. I bet that's a lot more cycles than are ever put on a tank that someone owns and just uses maybe 8-10 days a year.

Based on what I'd read on many tank threads here, your theory is probably true for aluminum tanks, but not really applicable to steel tanks, as steel has elastic properties that aluminum tanks do not.

 

[BRT]

From what I have heard (and I'm certainly no expert), the years of use is less important to the useful life of a tank than the number of cycles - filling a tank up to full pressure, emptying it down to 500-700 psi, refilling it, etc., puts stress on the tank. Each full cycle results in some measurable flexing of the side walls, and the constant flexing back and forth is what causes the metal to weaken. Like airframes, it is the number of cycles on an airplane, taking off, pressurizing the cabin, landing and depressurizing, that governs when parts are required by the FAA to be inspected and replaced - it is the cycles, not the age of the plane, that causes flexing on all the metal parts which leads to metal fatigue. So for Dave to say that he only gets three years, if the tanks are used and refilled 6 times a week, that puts nearly 900 cycles on those tanks. I bet that's a lot more cycles than are ever put on a tank that someone owns and just uses maybe 8-10 days a year.

Except that in Dave's world aluminum tanks get filled just as often and last for decades. I'm willing to bet that the steel tanks are not failing for too many cycles. I'm wondering if it is corrosion outside or inside that is taking them out of service.

 

[tbone1004]

bullsh!t on cycles for steel tanks, even for aluminum. Luxfer takes their aluminum cylinders to 100,000 cycles to hydro pressure. For reference that means the tanks would get filled 3x/day to hydrostatic pressure *5000psi*, 365 days/year for 91 years before they would even think about having a problem, this has absolutely nothing to do with fill speed, or number of cycles, it is 100% operator error, I'm sorry if this is offensive, but if tanks are becoming obsolete in 3 years then you need to look in the mirror and at your staff, not the bottles.

Improper tank maintenance by the operators is what is killing your tanks. You aren't VIPing them often enough, tumbling them often enough, ensuring that you are utilizing proper filling procedures by blowing off the valve and blowing out the fill whip before filling the tanks, doing adequate compressor maintenance to ensure your filters have the moisture content low enough, etc. That blows salt and moisture into the bottles and eats them from the inside out. Hot dipping is going to do a God damned thing about that.
With Fabers you probably aren't cleaning them properly and removing the boots regularly enough to wash them off or touching the paint up when they get scratched so they rust from the outside in. Hot dip will help from that aspect, but not from the problems above.

Again, if your tanks are only lasting 3 years as a dive operator, then you need to check back in on your operation because you are abusing your equipment and frankly you saying that a 3 year service life for a steel tank has me real hesitant to consider renting any gear from you

 

[kixy1]