How often to replace hp seat?

[halocline]

A scratch in the balance chamber could easily happen with a careless removal of that o-ring during overhaul. It's a little like the HP o-ring in the MK5/10 in that you have a relatively small o-ring in a tight space that has to deal with a big pressure differential.

It is very bizarre to me, though, that the HP seat is not included in the kit or replaced at annual service.

 

[LeadTurn_SD]

A scratch in the balance chamber could easily happen with a careless removal of that o-ring during overhaul. It's a little like the HP o-ring in the MK5/10 in that you have a relatively small o-ring in a tight space that has to deal with a big pressure differential.

It is very bizarre to me, though, that the HP seat is not included in the kit or replaced at annual service.

I have to agree.

While I like Mares diaphragm first stages, and find them really easy to service and pretty bullet proof, I really dislike their service kit philosophy. (Also, no diaphragm in the "annual" kits either... strange).

My guess (only a guess, since I'm just a DIY guy, not a tech or dealer) is that it saves Mares a little money to not include the "replace only when necessary" parts.... and just include the parts that always get replaced (some o-rings and the filter).

I'd guess the dealer has a parts bin full of 1st stage "annual" kits, another full of diaphragms, another full of the individually shrink-wrapped HP seats (that is how they are packaged when I've bought them).

During many "annuals" he/she will not need to dip into the diaphragm and HP seat bins since these parts have an "Official Blessing" to be reused if in good shape.

Now I actually like and approve of the idea of reusing perfectly good parts.... but I'd rather Mares included the HP seat and diaphragm, and let me have them as spares!

As a result, I've purchased several Aqualung Conshelf/Titan 1st stage service kits instead of Mares kits, since the Aqualung Conshelf/Titan kits DO contain the HP seats and diaphragms (and will work in the Mares regs I have).

Sorry for the derail and rant.

Best wishes.

 

[mbs]

+1 on why not including the seat in the kit... The replace every other year philosophy works if a - you go back to the same lds and b - that lds keeps track. And I guess c - if the lds listens to your request to replace it.

 

[redacted]

+1 on why not including the seat in the kit... The replace every other year philosophy works if a - you go back to the same lds and b - that lds keeps track. And I guess c - if the lds listens to your request to replace it.

Why would you want to replace something every year when it has demonstrated the capability to reliably last 2 or more years?

If the tech marks the seat when it passes inspection, it should get replaced the next year. If they do not mark it and it passes inspection the 2nd year it may well be good to go for another year. The common failure mode is some IP creep. If you are monitoring your regulator's IP, you can see the performance degradation before it becomes a problem. And, if you add a backup regulator to your kit, You can pretty much avoid any problem and still not waste $$ (and risk break in failures) due to unnecessary service.

 

[mbs]

Why would you want to replace something every year when it has demonstrated the capability to reliably last 2 or more years?

If the tech marks the seat when it passes inspection, it should get replaced the next year. If they do not mark it and it passes inspection the 2nd year it may well be good to go for another year. The common failure mode is some IP creep. If you are monitoring your regulator's IP, you can see the performance degradation before it becomes a problem. And, if you add a backup regulator to your kit, You can pretty much avoid any problem and still not waste $$ (and risk break in failures) due to unnecessary service.

Well time will tell on the new design seat... I'll certainly consider a backup 1st, but in the mean time that additional $22 added in to my annual seems like smart money to me. The last failure the ip was rock solid before vacation and then a dozen dives or so into the week my 2nd starts to bubble... So at least with the old design it was a fairly rapid onset of the problem. Also, the old seat design definitely did not "demonstrated the capability to reliably last 2 or more years." Quite the contrary which is the point of this thread. If the new design proves to be more reliable I'll happily reuse it till the cows come home

 

[Fishpie]

Just another observation.
The Proton 2nd stages that I have experience with needed frequent tweaking to stop the occasional burp and bubble unrelated to creeping IP.
Probably a combination of soft seat material, weak spring pressure and sharp seat edge.

 

[ajduplessis]

Once a year

 

[Nemrod]

Well time will tell on the new design seat... I'll certainly consider a backup 1st, but in the mean time that additional $22 added in to my annual seems like smart money to me. The last failure the ip was rock solid before vacation and then a dozen dives or so into the week my 2nd starts to bubble... So at least with the old design it was a fairly rapid onset of the problem. Also, the old seat design definitely did not "demonstrated the capability to reliably last 2 or more years." Quite the contrary which is the point of this thread. If the new design proves to be more reliable I'll happily reuse it till the cows come home

If that regulator is that unreliable that it cannot go hardly a year without failure of the seat, then I would not stop with a new seat, I would just get a new, non Mares regulator.

N

 

[Bigd2722]

Regardless, considering your request/instruction to replace the seat, the LDS should have tried to discuss it with you before just assuming he did the right thing. "I" probably would have agreed with his decision, but it was your money.

 

[halocline]

Why would you want to replace something every year when it has demonstrated the capability to reliably last 2 or more years?

If the tech marks the seat when it passes inspection, it should get replaced the next year. If they do not mark it and it passes inspection the 2nd year it may well be good to go for another year. The common failure mode is some IP creep. If you are monitoring your regulator's IP, you can see the performance degradation before it becomes a problem. And, if you add a backup regulator to your kit, You can pretty much avoid any problem and still not waste $$ (and risk break in failures) due to unnecessary service.

I think the issue here is that the kit does not include the seat, which means you're rebuilding the regulator without replacing the seat. Why rebuild at all if that's the case? Usually the whole reason to rebuild a 1st stage is, as you mentioned, to stop IP creep which means replacing the seat. To me, not including the seat is actually encouraging more unnecessary service.

Anyhow, mares is a weird company. Good for fins....