First stage keeping pressure after disconnect

[ERV]

Dear experts,

I started two years ago servicing my own Dacor regs as many shops refused to service them (too old; no parts). I started with the seconds as all tests were fine for the first stage.

This week I did a complete overhaul of first (balanced diaphragm similar to Dacor D16) and seconds (Dacor Fury and Fury adjustable) and noticed that after closing the tank valve, purging the system takes a few seconds; more than it used to.

All specs I can measure reliably (IP at 3K and 500 psi, cracking pressure of both seconds) plus leak and vacuum tests are fine and it breathes well (on the surface; no dives yet). However, when I close the tank and purge the system with the second stage purge button, it takes a while to purge. Furthermore, when I discunnect the tank, there is still some air that comes out of the first for, again, 4-5 seconds.

Is this a symptom of something wrong? E.g., pin lubrication, diaphragm sticking.

Your opinion is much appreciated.

Cheers,
ERV

 

[tbone1004]

it is likely either one of two things. second stage isn't actually purging all the way with the purge button, or the internals of the 1st stage are letting some tank pressure into the IP side after you are done with the purge. It isn't that abnormal and isn't something that I'd worry about as long as the IP is creeping. If it is the first stage though, I would keep an eye on the IP as it could be a sign of pending IP creep.

 

[ERV]

Thanks a lot tbone.
No IP creep so far... we'll find out

 

[redacted]

Some HP ports have such a small hole that it may take a while to emply the HP hose and SPG. If you want to verify that is what is going on, remove the HP hose and install a plug.

 

[emoreira]

Some HP ports have such a small hole that it may take a while to emply the HP hose and SPG. If you want to verify that is what is going on, remove the HP hose and install a plug.

Just to add my 2 cents, sometimes it's not the HP port, but the HP hose connector (the hose to the SPG) that has such a small pin hole that it takes a few seconds to relief the pressure inside the hose and SPG.

 

[tbone1004]

Some HP ports have such a small hole that it may take a while to emply the HP hose and SPG. If you want to verify that is what is going on, remove the HP hose and install a plug.

this could be it, and since it used to not do that, it could be something blocking that itty bitty pin hole. You can take it out to visually inspect. If you have an ultrasonic cleaner, it wouldn't hurt to put the first stage side of that hose in the ultrasonic to clean it out a bit

 

[sea_ledford]

I know noting about dacor regulators, however on a scubapro there is an oring that goes in one spot on a mk2 and goes in another spot on a Mk25, but otherwise all the parts look the same. The result of putting in the wrong place is exactly as you mentioned, weird SPG readings (full when disconnected or empty when charged slowly). Maybe check to see the HP port isn't being blocked by an o-ring?

-Chris