DIY Regulator Maintenance Discussion: MARES

[sambolino44]

Apparently there's some confusion as to the terminology. I was trying to use the terms from the parts list and exploded diagram in my Mares manual. I'm used to calling the fixed orifice that the air goes through the seat, and the moving rubber or plastic part that seals against it the poppet, and that's the way they're called by Mares. However, it looks like most people call the moving plastic part the seat. In the US Divers manual that part is called the HP Seat, and the orifice is called the Crown.

In the Abyss manual, both sides are called the seat. Go figure.

In reply to herman, I agree that the instructions don't seem to make sense to me, but I disagree with you on the seat adjustment having no bearing on the other parts except for lever height. Maybe the confusion comes from the above-mentioned confusion over the naming of the parts. The way I understand it, the orifice, or crown adjustment determines the amount of force needed to crack the valve open, and the locknut adjustment determines the lever height. But if by "seat" you mean what I was calling "poppet", then I agree with you, adjusting the locknut should not affect the other parts.

But the main point is that, if I followed the instruction to back off 3 turns, the hose connector won't go back into the body; you have to back it off more than that. I was wondering if anyone else has encountered a similar situation.

 

[herman]

Something is just not right.. let me try this way. I am looking at Abyss 2000 second stage Ref dwg E-19, Table 104 dated 30/10/2001. I will use the part reference numbers from that drawing.

The assembly should go like this. I will give very general adjustments.
1 Parts 47,30 and 31 (poppet seat , poppet and spring)are inserted into 32 (second stage case).
2 Parts 35,34 and 33 (lever, washer and nut) are installed next. The nut should be adjusted so a couple of threads are exposed.
3. Parts 21 and 27 (seat connector, oring) are installed into part 28 (case assembly connector). Part 21 is screwed all the way in and backed out 3 turns.
4. Part 28 and 29 (with part 27 and 21 installed inside it) are installed on to 32 and snugged up.

From here, you would install the hose (26), pressurize the second stage and adjust the part 21 (seat connector) for cracking pressure and then part 33 (nut) for proper lever height. You will likely have to back out 21 several turns to get into the balll park then tweek it by very small amounts to get it correct. To adjust 21, you must either depressurize and remove the hose, adjust 21, reassemble, repressurize and test again or use a special in line tool. This is going to take several attempts to get it right.
Lever height will be effected and you may need to return to the nut and readjust it.

 

[sambolino44]

I got my manual online, and I can't find a date on it anywhere, but the procedure you describe is pretty much what my manual says. Instead of "a couple of threads exposed" on the poppet body, mine says "until approximately 1/16" of the poppet stem is protruding from the nut."

The thing is, I don't want to turn the seat connector while it's rubbing against the new poppet seat, so I depress the lever, but the poppet seat bottoms out on the poppet before the case assembly connector is all the way into the case. So, what I did was back out the seat a few turns, snug up the case assembly connector, then turn the seat in until it contacts the poppet. On one reg, I then did what you describe in your last paragraph (I don't have the inline tool, so I was taking it apart every time). In other words, adjust the seat for cracking pressure, then adjust the nut for lever height. But on the other reg, there's no removable plug to get to the poppet nut without taking the diaphragm off, so I just adjusted the seat until the lever was the right height and then checked it. It turns out that the cracking pressure was OK, but that's actually a back-assward way of going about it.

So, you just crank the seat connector into your new poppet seat (Step 4)? Do you at least depress the lever while doing this? Also, can you check the cracking pressure without putting the diaphragm on?

thanks

 

[herman]

Yea, I press down on the lever to prevent rotating the seat (47) against the seat connector (21) while installing 28 (case assembly connector). If you can't fully seat the case connector without hitting the seat, just tighten up on the nut a few more turns, you are going to do a final adjustment on it later anyway.
The threads outside the nut are just a starting point, you are going to have to adjust it at the end.
Same goes for the setting of the seat connector (21), fully in and 3 back are just a starting point, where it ends up depends on a lot of factors like seat (47) thickness, spring (tension, age, ect) and the connector itself.

The only way cracking pressure can be tested is with the second stage fully assembled and the first stage IP set to it's final value. You can use the submersion method for a rough test or use a manometer or magnihelic for more accurate test. ......or you can use the " feels OK to me" adjustment, after all the value is really what you like as opposed to some required value.

 

[LeadTurn_SD]

I got my manual online, and I can't find a date on it anywhere, but the procedure you describe is pretty much what my manual says. Instead of "a couple of threads exposed" on the poppet body, mine says "until approximately 1/16" of the poppet stem is protruding from the nut."

The thing is, I don't want to turn the seat connector while it's rubbing against the new poppet seat, so I depress the lever, but the poppet seat bottoms out on the poppet before the case assembly connector is all the way into the case. So, what I did was back out the seat a few turns, snug up the case assembly connector, then turn the seat in until it contacts the poppet. On one reg, I then did what you describe in your last paragraph (I don't have the inline tool, so I was taking it apart every time). In other words, adjust the seat for cracking pressure, then adjust the nut for lever height. But on the other reg, there's no removable plug to get to the poppet nut without taking the diaphragm off, so I just adjusted the seat until the lever was the right height and then checked it. It turns out that the cracking pressure was OK, but that's actually a back-assward way of going about it.

So, you just crank the seat connector into your new poppet seat (Step 4)? Do you at least depress the lever while doing this? Also, can you check the cracking pressure without putting the diaphragm on?

thanks

Sombolino44,

I own and service Mares MR22/Abyss regs.

If I'm understanding your description, there may be an assembly problem you need to correct.

There should be no issues like the one you described with installing the hose connector, seat connector and poppet assembly if you follow the procedure in the repair manual.... unless the poppet assembly was not 100% correctly aligned.

This is difficult to do, but possible (to misalign it)... don't ask how I know .... so make absolutely sure that the squared edges of the poppet are lined up so that the poppet stem moves all the way through the opening when you fully compress the spring... you'll see maybe a 1/4" difference in depth? It is an obvious difference between "right" and "wrong" when you see it.

Don't go any further if you are not 100% sure that the poppet assembly is properly aligned.

If that turns out to be ok, then we'll continue.... but you should not have to back off the orifice ("seat connector") more than 3 turns from "bottomed out" to get a correct assembly....

Then of course you do need to tune the reg, adjusting both cracking pressure and lever height (together).

Best wishes.

 

[Happydives]

Hi Afishianado, can you tell me something about the other o-rings? You write the V-006 is 75 and is used in the first stage. But what about the BS610 / BS611 / BS 614 / AS568A -011 / AS568A -008. Can you tell me : are they Nitrile or Viton and what is their hardness, 70, 75 or 90?
Thanks a lot!!!
Happydives

 

[Afishianado]

Sorry for the delayed response, been a busy season for me.

all of the O-rings that I use are Viton. These days, I'm not sure why you would use anything else. They are cheap, durable, seal well, have a great shelf life, they are compatible with just about every situation, they are easy to get...I could go on

You will not notice a difference in performance between durometer 70 or 75, usually this difference is only from differing manufacturers. There are some applications where this difference is important, SCUBA regulators is not one of them.

You can use 70/75 for all of the Orings in these regs and have no problems 95% of the time. There is one exception however, sometimes the dynamic seals in some regs will last longer or seal better with a duro 90 O-Ring. This means seals where there is mechanical movement on that seal as part of the operation of the regulator. Personally, If I have the choice of 70/75 or 90 at the time of a bulk order I will choose the 90 for those specific cases but otherwise I just go with the 70/75 and replace as needed. It is cheap and easy to replace these if you are a DIY type.

 

[Afishianado]

Wow , so here we are a year later and 5000 views. Looks like at least some people are getting something out of it. I have been thinking about doing one for Aqualung/Apeks regs since I started this one. Any feedback on this thread would be appreciated going into the next one. What suggestions can you make for a better thread?

There are things I would have done differently knowing what I know now.

1. I cannot edit posts of mine that are more than 24 hours old on Scubaboard. Most internet forums allow this and my entire structure/layout would have ended up differently since that is how I normally do things like this on internet forums and planned to do in this thread, I will take that into account on the next thread.

 

[fjpatrum]

I am definitely getting something out of this thread Afishianado! Thank you very much for the detailed parts lists etc. And thank you Lucca Brassi for the Mares manual. Looks like a close match to my AMF MR12 so I think much of this information will be useful in my upcoming rebuild of an old one I got last year.

 

[acteg]

I read a couple of posts where people still had access to the factory rebuild kits. Anyone mind sharing the source via pm. Need to rebuild my mr22 and thought it might be easier to buy a kit then figure out o ring size and order bulk quantities. I already have a new diaphragm and I was going to reuse a HP seat from an mr12 I had serviced awhile back that is in perfect condition.