How often to replace hp seat?

[mbs]

History: I have had my mares proton for about 8 years and have had 2 hp seats fail (major creep) in that time. My old lds told me the hp seat needed to be replaced every other year. Just got our rigs back from my new (semi) lds and I had asked to make sure the hp seats were replaced in both. Well he did not replace mine because he said it was replaced with the new design (true - bruce at carib inn did it 2 years ago) and even showed me no ip creep. So my question is, a) was I right to be annoyed and b) what is the correct interval or even number of dives to replace the hp seat BEFORE it becomes a problem? I do maybe 40-50 dives/year and service annually.

 

[redacted]

I replace mine when it no longer hold IP the way I want it to. I check often and usually allow about 10 psi of creep before I replace them. I set IP on the low side to make plenty of room for some creep. Creep happens but normally progresses quite slowly so just check often. I always have a spare regulator so I can push it if I want to. My BP HP seats tend to last 5 years or more with satisfactory performance.

 

[flots am]

History: I have had my mares proton for about 8 years and have had 2 hp seats fail (major creep) in that time. My old lds told me the hp seat needed to be replaced every other year. Just got our rigs back from my new (semi) lds and I had asked to make sure the hp seats were replaced in both. Well he did not replace mine because he said it was replaced with the new design (true - bruce at carib inn did it 2 years ago) and even showed me no ip creep. So my question is, a) was I right to be annoyed and b) what is the correct interval or even number of dives to replace the hp seat BEFORE it becomes a problem? I do maybe 40-50 dives/year and service annually.

Regardless of any technical details regarding the exact state of your existing HP seat, you paid for service and you paid for a service kit and they should have done a proper job which includes complete disassembly, cleaning and replacement of everything in the parts kit, as well as everything else that needs replacing.

While I have no direct experience with Mares, I would expect the HP seat to be included with the first stage service kit and should have been replaced at service time. Even if it wasn't included with the kit, the parts cost for a new seat is insignificant when compared to the cost of service, so they should have replaced it anyway.

If they didn't change the seat, I'd want to know what they did change. Did you get back a bag containing your old o-rings, etc.?

flots.

 

[Fishpie]

I know that Mares only requires replacement of the HP seat every other year and inspection every year.....the seat is not in the kit and is expensive.
The old seat was terrible and frequently wouldn't last a single year. The newer tri-material seat is much better.
Can't tell you how much better as I only use the blue AquaLung seat in my mares reg after the old seat problems.....these will last at least 4 years.

 

[Zung]

Actually, Mares doesn't include the HP seat in their annual kit: it's a separate order/extra cost item. See here. The kit contains a snap ring, a backup ring, a filter and some o-rings, that's it. I guess the packaging costs as much as the content.

 

[mbs]

Thanks folks. Of course each time it failed I was away on vacation and not in the local quarry So I thought that the every other year replacement rule made sense to avoid the problem. I have an ip gauge since the first failure so I do check it. Yes I did get the parts bag back. Cost seems irrelevant since they were just going to pass that charge on to me anyway. I have heard from several folks that the new seat is dramatically better than the old so I'm hopeful that it won't become a problem!

 

[herman]

As to how long they will last....who knows, I have seen some very old Conshelfs (same style seat) and even older DA Aquamasters (similar seat) that are in perfect working order after decades of use. Unless they are giving trouble, are the old black hard material (which still works but is more prone to problems) or for some other reason look bad I don't replace them on my regs. Most of us that DIY service press the interval a lot longer than 1 or 2 years. I tend to go 5+ unless the reg is giving me issues, which is rare. Most failures come one slowly so frequent IP checks will catch most problems before they become a big deal and I carry a spare reg so swapping to a backup is easy.
While you could be annoyed that your LSD did not replace them as you ask, another way to look at it is he did a proper inspection, detemined that you did not need an expensive part (that he would have made profit on) and he believed he was doing the right thing by saving you money....he could have just as easily not replaced it, told you he did and if ask, gave you an old seat he had laying around. If they came with the service kit, that would be a different matter but since Mares HP seats don't, IMO your LSD did you right.

 

[mbs]

...While you could be annoyed that your LSD did not replace them as you ask, another way to look at it is he did a proper inspection, detemined that you did not need an expensive part (that he would have made profit on) and he believed he was doing the right thing by saving you money....he could have just as easily not replaced it, told you he did and if ask, gave you an old seat he had laying around. If they came with the service kit, that would be a different matter but since Mares HP seats don't, IMO your LSD did you right.

Yea, you are right... I was just sensitive since I have had 2 failures already and explicitly told him to change it... Now if you hear back from me next month from Bonaire, posting because I'm not diving while Bruce replaces another hp seat...

 

[ams511]

I would express your concerns to the LDS and ask to purchase a HP seat before your trip to Bonaire or buy one from NESS. BTW, the Aqualung seat is less than half the price of the Mares seat.

 

[herman]

Not to go off track here but a balance chamber oring can also cause some major creeping and frankly I tend to suspect them first before the HP seat. Any good tech is going to change them anyway when he is in there which can cover up a balance chamber problem for a while. One failure mode that is hard to find is a scratched balance chamber. How long it goes before being an issue is a matter of scratch size, placement, oring condition/durometer, lube viscosity, temperature and plain old bad luck. When a balance chamber oring is replaced it is usually lubed fairly heavily. That lube can fill a minor scratch in the chamber for a while but it will evenutally work it's way out causing a fairly quick and at times significant creep/freeflow. Unless the tech is actually looking for the problem as opposed to shotgunning it (swapping all the parts and hoping) he will likely never find the issue until you chew him out over it and even then it's going to take a good tech to find it as opposed to a parts swapper. Moral of the story, all creeping is not due to the HP seat.