What are the symptoms of a too-short pin in RAM?

[FlyernDiver]

I am chasing my tail with IP creep in my RAM at tank pressures of 2500psi or higher. I had originally hypothesized that I had scratched my balance chamber, so I spent a lot of time buffing the interior of the chamber to near-perfection, my woes did not end however. Then I thought I should really get a spring block that accommodates a backup ring , so I pulled some parts out of a recently overhauled and working Conshelf with the same results. I put in a brand new HP seat--no change. The nozzle orifice looks great. So now I'm back to square one, and mostly fishing, I have about 1/16" gap under the mushroom, perhaps a fuzz less, it's tough to mic it...

Will a slightly short pin cause IP creep and a fluttering/honking noise at tank pressures above about 2500psi? It wants to lock-up, at whatever I set, but then the IP continues to slowlllyyyy rise (maybe 1psi per second) to about 160 before the leaking starts...

Thanks for any light you can shed on this mystery!

 

[duckbill]

Maybe the "fluttering/honking noise", but not IP creep.

 

[FlyernDiver]

Well I will cut a new pin then for good measure. 3/32" gap is what is called out if I recall correctly? Any other guesses on the creeping IP?

 

[Nemrod]

Well, let me ask you this, what HP seat do you have? I have had horrid luck with even NOS RAM seats and unstable IP and IP creep. The blue Titan seats generally cure exactly what your describing.

N

 

[FlyernDiver]

I have now put in two of the blue Teflon seats. The first one looks okay still, but I figured 'what the hell'. Maybe at this point I will let it sit overnight and think about the grief it's caused me.

 

[Paladin]

How about a nick in the volcano orifice that lets air leak past?

 

[Nemrod]

I am somewhat concerned about "polishing" the volcano orifice? I like to leave that alone, rounding it over or causing an uneven rim can result in permanent and irreparable IP creep.

Are the diaphragm spring coils touching (the big spring that adjusts IP)?

You have confirmed the order of parts?


Quote:
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Then I thought I should really get a spring block that accommodates a backup ring , so I pulled some parts out of a recently overhauled and working Conshelf with the same results.
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I am not understanding this above statement exactly? You should use the correct spring block and springs.

The little O ring and Teflon backup washer, you got a new O ring in there of the proper type and the back up is correctly placed?

A short pin will not cause creep, it is conceivable a pin way too long might.

Just trying to help you figure.

James

 

[FlyernDiver]

I will take a good look at the volcano orifice with a loupe in some good light tomorrow, but it has been perfect every other time I looked at it. I am also wary of touching it with any abrasive...

The main spring is in good shape--not even close to binding. The adjusting screw is protruding .0935 inches give or take a few thousandths. It is the original, when I ordered the platinum kit from Bryan, this was the one part he did not have any of. However, because it's not binding I don't really see how that could be an issue... Can a spring's yield curve be bell shaped???

As to installation order, I put the backup ring into the spring block first (curved recess out) and then the o-ring, very slight Christo lube sheen on the o-ring. This is actually counter to the way it is shown in the USD double hose manual I downloaded from VDH, but it jives with the Conshelf manual and with everything I've read on the various forums, and it jives with what I understand the parts do. This is the correct installation order I hope?

As to the confusing statement: I was trying to summarize my troubleshooting already done. The OEM spring block that was installed when I took possession of this reg was the early style with room for only an o-ring. As I understand it, later models are slightly larger in order to accommodate an o-ring as well as a backup ring for the purpose of withstanding higher pressures. So in my research I found that the Conshelf part is the same--so I borrowed a "known good" part from one of my other not-quite-vintage regs. I put it into the RAM. The problem persists, but maybe at a slightly slower rate of creep.

I have attached a photo. I circled the original parts in red and what I am working with now in green--again borrowed from a recently overhauled, well performing Conshelf. The photo is from a doc at VDH and it shows the lineage of the RAM spring block/balance chamber.

I have zeroed in on the balance chamber because it wants to lockup and it only creeps on a full AL 80, half full-okay, and 200psi-okay. From the suggestions you are giving me, it sounds like I am on the right track and I must be missing some defect somewhere...

Thanks for all your help guys!

 

[captain]

I would bet on a nick in the volcano orfice, you seem to have covered everything else. You wouldn't believe how small a nick can be and cause a problem.

 

[captain]

I will take a good look at the volcano orifice with a loupe in some good light tomorrow, but it has been perfect every other time I looked at it. I am also wary of touching it with any abrasive...

The main spring is in good shape--not even close to binding. The adjusting screw is protruding .0935 inches give or take a few thousandths. It is the original, when I ordered the platinum kit from Bryan, this was the one part he did not have any of. However, because it's not binding I don't really see how that could be an issue... Can a spring's yield curve be bell shaped???

As to installation order, I put the backup ring into the spring block first (curved recess out) and then the o-ring, very slight Christo lube sheen on the o-ring. This is actually counter to the way it is shown in the USD double hose manual I downloaded from VDH, but it jives with the Conshelf manual and with everything I've read on the various forums, and it jives with what I understand the parts do. This is the correct installation order I hope?

As to the confusing statement: I was trying to summarize my troubleshooting already done. The OEM spring block that was installed when I took possession of this reg was the early style with room for only an o-ring. As I understand it, later models are slightly larger in order to accommodate an o-ring as well as a backup ring for the purpose of withstanding higher pressures. So in my research I found that the Conshelf part is the same--so I borrowed a "known good" part from one of my other not-quite-vintage regs. I put it into the RAM. The problem persists, but maybe at a slightly slower rate of creep.

I have attached a photo. I circled the original parts in red and what I am working with now in green--again borrowed from a recently overhauled, well performing Conshelf. The photo is from a doc at VDH and it shows the lineage of the RAM spring block/balance chamber.

I have zeroed in on the balance chamber because it wants to lockup and it only creeps on a full AL 80, half full-okay, and 200psi-okay. From the suggestions you are giving me, it sounds like I am on the right track and I must be missing some defect somewhere...

Thanks for all your help guys!

Put all the 1st stage internals in the other regulator you got the balance chamber from. If it doesn't creep it's the volcano orfice.