Mares new "tri-material" HP valve assembly

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Greg Barlow

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I have been using and servicing Mares regs since the days that the MR22 was considered to be a new model. One fairly common problem area was that of the HP valve assembly failing before 100 hours or so accumulated on the reg, particularly when pressures in excess of 200bar/3,000psi where used. The laminated material would often show evidence of a small "chunk" of material missing, thereby causing an increase in the intermediate pressure. Mares experimented with different laminates, and with various finishes but the problem persisted. They even marked the poppet with symbols to make a valiant attempt of determining which ones worked better than others.

I am very pleased to report that their latest strategy has taken a very different road. They are now using a poppet that is composed of three different materials. It has a much thicker pad of translucent polymer that mates to the HP orifice. The shaft is also covered with a synthetic material that should seal better to the O-ring in the balance chamber, and be less effected by normal wear.

After having obtaining a supply of these new versions, I carefully examined them to better comprehend the engineering changes. One very impressive point is the incredible consistency in tolerances from one example to another. I found that the exterior dimensions are held to within 0.001" in the six that I have in my possession. For those of you not familiar with that measurement, a human hair will often measure around 0.003". This is pretty darn impressive.

I am going to be installing these new poppets in a number of my Mares regs. I am also going to keep accurate records of their performance, and longevity. If I have enough interested readers, then I can even post the results every few months or so.

Greg Barlow
 
Greg, although I'm not that technically inclined, all bits of information are interesting to me. Even though it might never be of importance to me and my V16...

Cheers!
 
It's about time that Mares has addressed this problem which, to my knowledge, has been ongoing for more than 20 years.

When I was in the water almost every day, and diving a Mares MR 12, it was not unusual to go through 2 or 3 high pressure seats a year. Since the shop I worked for replaced them free, and since I was at the shop quite often, I put up with it. When I left and went on to other things, my Mares reg and I parted company.
 
This is certainly not only a Mares problem area. Manufacturers have been battling this headache for a long time. One need only look at all the HP valve changes that ScubaPro has made on their balanced piston models. It is probably the toughest design area in a regulator.

Greg Barlow
 
I am going to be installing these new poppets in a number of my Mares regs. I am also going to keep accurate records of their performance, and longevity. If I have enough interested readers, then I can even post the results every few months or so.

One year later, any news out there ?

-thanks-
 
One year later, any news out there ?

-thanks-

Yes, not a single one has developed any problems at all. The intermediate pressure is completely stable with no drift at all.

Greg
 
two years latter, any news out there ?

-thanks-


regards,

Yes. One needed to be replaced while on a cave diving trip last December. While checking the IP on my four regs prior to the dive, I discovered that the back gas right post MR12 demonstrated creep. It would initially stop at 140psi, and then began creeping slowly to 145 or so. I replaced the poppet, but could see no visible deformities. I also replaced the HP balance chamber, as I could see a small scratch on the interior wall. It is hard to determine as to what created the failure. Of course, back gas cylinder pressures of 3,600 or so might have played a role in it as well.

Another one of my deco regs displayed creep around 6 months ago. I saw a "chipped" spot on the face of the valve. After a complete rebuild, it began leaking again just a few dives later. Under magnification, I could see a small "burr" on the integral hard seat. Using a fitted polishing tool, and 800 grit compound, I refaced the surface. Since then, no more problems. I certainly can't blame either HP poppet for the problem. When I noticed that the second seat demonstrated the same type of "chip", I grew suspicious of the hard seat.

The back gas MR12 first stages have now been in service for literally hundreds of dives. I am planning to obtain two of the new MR12S (shorter body with satin finish) to use in their place. The older ones will likely go on deco/stage bottles.

Thanks for asking for an update.

Greg
 
I was speaking to a guy who used to service various regs. After mentioning that i have a Mares MR22 tri-metal FS and Abyss 2ndS/Octo. He also a lightened to the fact that they seem to have a high failure rate of the HP seats? Total Greek to me but it is a reason for me to start questioning my reg.

Would you say that this is something i should be concerned about?
 
I was speaking to a guy who used to service various regs. After mentioning that i have a Mares MR22 tri-metal FS and Abyss 2ndS/Octo. He also a lightened to the fact that they seem to have a high failure rate of the HP seats? Total Greek to me but it is a reason for me to start questioning my reg.

Would you say that this is something i should be concerned about?

Prior to the introduction of the "tri-material" seats, the Mares HP valves were inconsistent in their longevity. I had some regs that could go for hundreds of dives without issues, while others needed replacement in as few as fifty or so. Mares experimented with many different compounds and molding techniques trying to solve the issue. They even used symbol coding on the parts to see if different combinations were superior. It was after this testing that they decided to "think outside the box", and come up with an entirely new design. The great part is that the new valves retrofit the older regs.

I was always a fan of the Mares SCS system. This was used in a number of different models. I still have some regs using the system, as they have not been converted over to the tri-material assembly. Mares decided to make all of the diaphragm regs consistent. That is why they now all use the same system of HP components.

Greg
 
https://www.shearwater.com/products/teric/

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