Removing the diaphragm from a second stage

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Here are some photos of the inside with the diaphram removed. The first is looking underneath the arm that is depressed by the purge button. In case it's not obvious there's a metal plate on the back of the diaphram that this lever rolls across.

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Looks similar to the inside of a Conshelf.

Adjustments are made by turning the nut you can see. You have to hold the end of the shaft from turning with a small flat blade screwdriver (you may have to bend the screwdriver to line up the blade correctly or you may be able to unplug the other side of the case and put the screwdriver through there).

Turn the nut counter clockwise 1/8 of a turn at a time and pressurize the reg to check for the leak between adjustments. It should take less than a 1/2 turn to make it stop leaking.

If it continues to leak, the seat may need to be replaced or the orifice might have a nick in it.
 
OK, made some baby-steps. I pulled the plug from the opposite side of the housing and I now have clear access. There was a distressing amount of sand between the plug and the housing. I'm guessing from my last dive in Carlyle Bay Barbados (tons of sand suspended in the water). Is it likely that there is sand in the demand valve itself? If so is there anything special I should do to avoid (further) damage?
 
Welcome to the Dark Side!

It won't hurt your second stage to remove the hose (use two wrenches.) Then in a clean sink dunk it, swish it around, and exercise the purge button. Reattach the hose and blow it out. Test it again.

Having said that, it's not likely that sand got into the demand valve, but salt has a tendency to appear where it seems impossible. After each day of diving be sure to rinse both the first and second stages. At the end of a dive trip soak all of your equipment overnight if possible to dissolve any salt crystals that may have formed. Agitate if possible.

I'm more of a Scuba Pro man, so I'll let the guys who are most familiar with Conshelfs advise you on making minor adjustments. Take note of the lever height before making any changes.

@herman @GJC @Nemrod @Luis H @Bryan@Vintage Double Hose
 
I read through this and I am trying to understand, why are we taking our regulator apart? Did I miss the reason? And what is the regulator again?

To remove a stuck diaphragm, you could just blow forcefully into the mouthpiece. That usually pops it out. Especially with warm, soapy water.

Yes, by all means, remove theLP hose. The hose attaches to the low pressure orifice/knife edge which screws into the regulator body. You will need to restrain the orifice with one wrench and break the hose (nut) with the other. Then remove the LP orifice from the regulator housing. When you do so it is customary to depress the lever. Depressing the lever raises the LP seat from the orifice preventing the knife edge of the orifice from being damaged and possibly cutting into the LP seat material as it is rotated to screw out or in.

The 120 psi is not terribly low, especially if the regulator is used for cold water diving but I would probably bump the IP up to 135 psi or close but no higher. That is a first stage adjustment.

Since it is apart, put in a new seat.

N
 
why are we taking our regulator apart?

Hi @Nemrod The op removed the diaphragm to see if there was anything in the box that could be causing a minor hiss he hears coming from the demand valve. The second stage only has a few dives on it, so at this point it may just need a bit of soaking and perhaps a small adjustment to the cracking pressure. I summoned you guys that have experience with Connies as the OP's reg looks like it has a similar demand valve.
 
Since it is a new second stage I suspect the LP seat has taken a set. Probably turn the seat out about a 1/4 turn or whatever it takes to stop the hissing. The lever will drop a little as a result. I am not awake yet. Maybe before doing anything now that it is rinsed out, see if that alone fixes the issue. I doubt sand got in the LP seat but it could get in and around the other parts like that odd roller.

Oh, and then go get yourself a real Conshelf XIV!

James
 
The valve assembly looks like an older Sherwood with the roller on the lever. My GUESS is the LP seat has taken a little set and needs to be adjusted. A slight turn of the orifice may do it but that can also affect lever height which would then may need adjustment. How that is done and to what degree varies with regs so a manual would be helpful, otherwise it's a educated guess.
 
Could be some sand or salt in the washer against the lever. Thorough soak and flush may help.

If adjusting the nut doesn't create a good seal, I think it needs to be completely taken apart and serviced.
 

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