2 year service interval

[dougr52]

does any other mfg make a regulator with a recomended service interval of 2 years other than MARES ??

 

[Scott L]

Atomic...

 

[keyshunter]

Aqualung/Apeks uses 2 years as a full service interval to maintain their free parts "warranty", with LDS checkup on intervening years.

 

[Hallmac]

does any other mfg make a regulator with a recommended service interval of 2 years other than MARES ??

Most do, the reason is universal..... Flex life of o-rings.

The Society of Aerospace Engineers (SAE) issued Aerospace Recommended Practice (ARP) 5316 was issued in 1998 to supersede MIL-HDBK-695C (canceled) as the aerospace industry standard. ARP 5316 is often used as a guideline in determining useful shelf life of elastomers used in other industries.


5 years: Polyurethane (millable), SBR, Natural Rubber, Polybutadine, Polyisoprene
15 years: Nitrile, Neoprene, HNBR, Polyacrylate, Butyl
Unlimited: Ethylene Propylene, Fluorocarbon, Perfluorinated Elastomer, Silicone, Tetrafluoroethylene Propylene (Aflas®), Fluorosilicone.


Elastomer........................................... ASTM...............ARP 5316 Shelf Life
Butyl Rubber, Isobutylene Isoprene...............IIR........................15 Years.

Ethylene Propylene, EPDM or EP.....................EP.........................Unlimited

Fluorocarbon (Viton®)..................................FKM.......................Unlimited

Hydrogenated Nitrile, HNBR or HSN.................HNBR.....................15 Years

Nitrile (Buna-N or NBR)..................................NBR.......................15 Years

Polyurethane (Polyester or Polyether)...............AU / EU..................5 Years

Silicone.........................................................VMQ.......................Unlimited

Styrene Butadiene (Buna-S)............................SBR.......................5 Years

If you noticed the shelf life of Polyurethane and Buna-S are 5 years, that is just sitting around with no work load and only oxidation from air.

Once compressed, the memory and life span drop drastically. Both have been commonly used in low stress positions in the regulators to save money in mass production.

By using the 1/2 life of the weakest link it is easy to figure a safe recommendation to insure the unit performs as required.

 

[LeadTurn_SD]

does any other mfg make a regulator with a recomended service interval of 2 years other than MARES ??

Regarding Mares: The "Tri-Material" HP poppet in the 1st stage of the Mares diaphragm regs is designed as a 2 year / 200 dive component.

The service interval, however, is one year. At the annual service, the HP poppet is inspected, and if in good shape the numeral '"1" is carefully scribed on the back side of the poppet, indicating it is being reused once; this "1" scribed on the back of the poppet will alert the tech at the next annual service that it is "time" to change the HP poppet....

Having recited the "official" Mares policy from the tech manual.... I inspect very frequently, but don't service annualy. I've been getting well over 2 years with our 2 Mares MR-22's between full rebuilds (and 3 of my MR-12's are approaching 4 years and IP is still rock solid).

Most brands are probably similar. It all depends on amount of use and the environment the reg is used in, proper cleaning and storage, how well the internal "lube" retains its properties, and a little bit of "luck".

Best wishes.

 

[Mr Carcharodon]

Cleaning, re-lubricating seals and tweaking the low pressure seat adjustment is all more critical than replacing the o-rings. Of course the dynamic o-rings do wear in use, and springs do wear out over time. It is a mistake to think that o-ring elastomer shelf life is the only thing driving service interval. But a 1 year service interval is very conservative, and given how many failures occur due to mistakes that occur during servicing is of questionable benefit.

Most end users should be able to check their regulators for leaks (vacuum leaks in the second stage, and leaks of gas out), cracking pressure and intermediate pressure. Those checks should be enough to give a strong indication if service is needed or not. Assuming those checks are done pushing beyond 1 year is perfectly reasonable for all regulators. Of course the end user has to decide if they want to do those checks, or have their LDS do them. The warranty "free" parts that come with annual service also usually come with a $100-$150 labor charge. You can decide for yourself if a $100 free service is free or not.

 

[dougr52]

Regarding Mares: The "Tri-Material" HP poppet in the 1st stage of the Mares diaphragm regs is designed as a 2 year / 200 dive component.

The service interval, however, is one year. At the annual service, the HP poppet is inspected, and if in good shape the numeral '"1" is carefully scribed on the back side of the poppet, indicating it is being reused once; this "1" scribed on the back of the poppet will alert the tech at the next annual service that it is "time" to change the HP poppet....

Having recited the "official" Mares policy from the tech manual.... I inspect very frequently, but don't service annualy. I've been getting well over 2 years with our 2 Mares MR-22's between full rebuilds (and 3 of my MR-12's are approaching 4 years and IP is still rock solid).

Most brands are probably similar. It all depends on amount of use and the environment the reg is used in, proper cleaning and storage, how well the internal "lube" retains its properties, and a little bit of "luck".

Best wishes.

hey leadturn,
i have a mr 12, been over 100+ ft several times, breaths great at all depths, never any problems, but i am looking at a 22 is it really any better ??

 

[Hallmac]

Mr Carcharodon maybe I should have worded that as: Why or Where the two year recommendation originally came from.

I can agree with your practical assessment other than re-lubricating old o-rings as more important. One thing I definitely agree with is everyone should have the option to service their own gear and know the basic checks.

The two year or 50 dives whichever comes first recommendation has been around for a long time, and is simply based on the materials used or even worse what the other guys have always done and seems to work for them. It is a small community after all.

The weakest link at the time I first remember seeing it was the Buna-S material. It is rarely used today by the way. I can't even come up with a number of times I have removed a well lubricated carbonized o-ring from a malfunctioning reg. It has happened a lot. Half life was an easy sale to the lay person who did not have engineering or mechanical foundations to drawl from. Legal departments liked the half life reliability numbers and were comfortable with it for warranty and liability concerns.

There are several manufactured Regulators that in real life can exceed triple the use and age of that recommendation and still function reasonably well. Right now, there are people buying regulators, "brand new" in the box from dealers that were actually manufactured and boxed 5 to 10 years ago. They will dive them for a couple of years before they are serviced never knowing the truth. That is the actual reality, it is known and hushed.

Personally, I am willing to bet the failure rate of so called "new" regulators is largely due to the oxidation of parts while they sit around waiting on being sold and not as much the failure in manufacturing quality, although that does happen.

 

[LeadTurn_SD]

hey leadturn,
i have a mr 12, been over 100+ ft several times, breaths great at all depths, never any problems, but i am looking at a 22 is it really any better ??

Short Answer: Yes, I think the MR-22 is better.... but no, you probably will not notice any difference if you upgrade from an MR-12 (assuming the same 2nd stage).

Long Answer: And here is why

I believe MR-22 is capable of higher flow rates at depth.... But few divers will ever be in a situation to use this extra capability. On a normal dive, I honestly cannot tell the difference between the MR-12 and MR-22. They both supply more air than I can use.

I like the hose routing a little better with the MR-22.... my MR-22 is a slightly older model, not the current "light weight" MR-22 (same regs, the newer MR-22 was just shaved down a bit to save weight).

The stage that makes the biggest difference in breathing performance is the 2nd stage. I really like the Mares Abyss 2nd stage. It is my "go-to" 2nd, and is the favorite 2nd stage I own (I currently own Mares, Scubapro and Zeagle regs). But like all classic downstream 2nd's, it needs to be "tuned" properly by the tech.

Anyway, the MR-12 is a "tried and true" workhorse, like the Aqualung Conshelf. If you couple it with a Proton Metal or Abyss 2nd stage you'll have a terrific reg.

You can also mix and match firsts and 2nds.... I've run Scubapro and Zeagle 2nd's on my MR-12 1st stages... But as is good practice with any 2nd stage, you need to "tune" the 2nd stage to match the intermediate pressure of the 1st stage.

Best wishes.

 

[LeadTurn_SD]

.... Right now, there are people buying regulators, "brand new" in the box from dealers that were actually manufactured and boxed 5 to 10 years ago. They will dive them for a couple of years before they are serviced never knowing the truth. That is the actual reality, it is known and hushed.

Personally, I am willing to bet the failure rate of so called "new" regulators is largely due to the oxidation of parts while they sit around waiting on being sold and not as much the failure in manufacturing quality, although that does happen.

Good points.

If I had to guess from just my own limited DIY experience, the "shelf life" of the original lubricant from the factory might be a big factor. I'm getting longer intervals between rebuilds now compared with the initial out-of-the-box lifespan of my regs... and I think this was simply due to my regs having sat in the box for a few years before I bought them...

I'd love to say that their improved lifespan between rebuilds is due to the care I take in rebuilding them, but it probably is just the "freshly lubed" parts

Best wishes.