RAM Problems

[treasureman]

What I like about this forum is the wealth of knowledge. I went from a Double hose user from back in the 1970's, to now knwoing what makes them tick, and while not an expert like some of you, the knowledge base increases as i read each post.

ther clearly are some tips and tricks that you pros use, and it is nice to hear of them. Knowledge when shared can never die. As we get older and kick, the next generation will know hopw these work and carry on for us. Not taht I am ready to kick or anything.. just pointing out that nothing is for ever. egads what a downers. time for a wee dram of some Ardbegh

[luis]

Wow, I am slow typing. Three new messages were posted since I started writing my response.

[Nemrod]

BUT, maybe it is just I broke my glasses and caanot see but that spring crown that is broken has a closed top which means it is for a RAM right? I don't have my manuals here in front of me since I cannot see them anyways, have I gone backwards?

James

[Nemrod]

OK, your right, me wrong, I am mixed up. The closed top should be the RAM and the open top the DA. Confusing huh? It is easier to do than to describe. Somehow I usually manage to get the correct parts in there and nothing explodes--usually. Luis is right--of course.

I am pretty sure this RAM I have is a very last one and it has a silver round crown that is closed on top to form the chamber.

Just a curious thought but in a rebuild, why replace this original part with a Conshelf part? It seems to be a very low wear item--normally.

James

[luis]

Nemrod

I forgot; the pin holder (mushroom cap looking part) looks like it is from a Conshelf. The RAM and DA Aqua Master ones are shorter. If you want to use a Conshelf pin holder on a RAM I think you may want to cut it so it doesn’t interfere or restrict the air flow inside the first stage nozzle.

The approximate maximum heights from the curve section to the top of the pin socket are as follow:
RAM or DA Aqua Master: 0.205”
Conshelf: 0.312”

[Nemrod]

I am sitting here working on my regulators because the shop a/c is broken and it is to hot outside to mow the field.

The white ring is indeed a back up ring. Oddly, all of my RAMs have a black one. I don't replace that part unless I had some reason to think it bad.

Weird huh how al these little bits mysteriously change over the years and yet perform the same function. Was it a design change, a vendor change, an engineer change (did USD even have an engineer?)

Well, here I go, delving into the mysteries of the Mistral---back in a bit.

James

[luis]

I am pretty sure this RAM I have is a very last one and it has a silver round crown that is closed on top to form the chamber.

Just a curious thought but in a rebuild, why replace this original part with a Conshelf part? It seems to be a very low wear item--normally.

James

I can’t keep up. You guys type too fast!

The old RAM spring block/ crown works fine, but the new Conshelf is taller (0.42” vs. 0.35”), the O-ring capturing groove has more room, and I believe it also guides the seat stem better.

The O-ring capturing grove in the new Conshelf spring block is the same diameters but deeper. This makes it a lot easier to replace the O-ring and the back-up ring (there is room for the rings to be pushed in and then turn to there working position). This a major advantage when servicing the regulator. With the old spring block it was sometimes a royal pain to replace that O-ring.

[treasureman]

if the new conshelf block is taller. would that mean that there would be more pressure (downward) applied to the ends oif the prongs on that block, as well as the corners of the block being driven into the second edge of the nozzle?

I have enclosed a pix of teh nozzle. Note at 11 o click, two oclock and four oclock the edged on the nozzle are for the lack of a better word burred downward from wghere the block was sitting. Is this normal. I do not recall seeing this sort of thing on a regular ram Crown.

[luis]

The extra height is only on the barrel were the O-ring is located and the depth of the LP chamber. The other interface dimensions should be the same (were the springs touch etc.). It is supposed to be a direct replacement.

I don’t think the spring block is normally supposed to go deep enough to touch that edge (except maybe during installation, if you are using the old pushing with a dowel technique).

The combination of a weakened corner hitting the inside of the nozzle during installation could explain this incident. Again this is total speculation, based on very little information and a few semi-clear pictures.

I will try to look more into the spring block position later.


PS. Sometimes I hate the English language. At first I typed weekend instead of weakened and of course the spellchecker didn’t catch it…LOL

[treasureman]

It was no doubt put together with the proper tool, as it was a complete set i bought from VDH. Can a old style block be used with a conshelf HP seat, or does the new block have to be used? Is there a performance difference from old to new block?

I looked at one of the old blocks and thought about replacing an oring, but it looks like a real pain in the butt

[Bryan]

When I put them together, I put the HP seat, main spring and crown in place and then push the assembly down with the center rod of the HP assembly block tool a time or two to make sure it moves freely and does not bind. If all is good I put the top spring and filter in place and then put it back together with the tool using the split ring clip. From looking at the whole thing, two possibilities come to mind......It snapped off when I did the final assembly and the small piece got out of whack then and worked it's way around the assembly as it was tested and or during diving....Why the problem did not show up right away I do not know?? Or it happend after it was under tension over a period of time?? Only guessing here....The grooves in the HP nozzle lead me to belive that it had been working off center for some time and thus wore the grooves ? Still only guessing here....

[Bryan]

You can use the old crown with the new HP seat.....The new crown is simply a superior design so I use it unless the RAM already has a crown with the nylon backup ring.

[treasureman]

How goes the diving Bryan? Any wrecks visited?