Showing off my newly rebuilt Conshelf 20

[Scuba Lawyer]

I just rebuit a Conshelf 20. Man, with that side 2nd stage adjustment port the thing breathes beyond belief. Cracking pressure is 0.5" H20 so I'm a bit worried about freeflow on a dive. We will see.

Hoping to get out and test this reg, and others, soon.

Here are a few SHR I've rebuilt lately. The Conshelf 20 is the only one I haven't taken into the ocean yet.

 

[rsingler]

Cut the finger off a rubber glove, and after removing the mouthpiece, pull it over the mouthpiece tube to provide a little backpressure. Maybe add a rubber band to hold it. Put the pressurized reg into the sink and see whether when you roll just past face down (i.e., exhaust valve highest) she bubbles. IMO, 0.5" is a tad light.

 

[rsingler]

Forgot to mention...
That was 0.5" at full tank? Remember that IP will rise on the Conshelf as tank empties. With a downstream second stage at IP 130 with a full tank, you may have 0.5" cracking effort.
But with a tank at 300psi, and an IP that has risen to 138, you may now have freeflow right when you really need that last bit of gas.

 

[Scuba Lawyer]

Forgot to mention...
That was 0.5" at full tank? Remember that IP will rise on the Conshelf as tank empties. With a downstream second stage at IP 130 with a full tank, you may have 0.5" cracking effort.
But with a tank at 300psi, and an IP that has risen to 138, you may now have freeflow right when you really need that last bit of gas.

All good info. Thanks.

IP is 135 psi on 500 psi tank pressure and that is where I measured the 0.5" cracking effort. I recall IP was slightly different at 2400 psi (which is the highest pressure tank I have and use), but not by much.

 

[Couv]

...I just sold (damn near gave away) a yeller one just like that. If I had known you were into those I'd have sent it to you.

 

[Scuba Lawyer]

@couv

Well Robert, I appreciate the thought!. I'm not exactly "into them" but a dive buddy of mine bought this one when they first came out and maybe used it once. He is now in declining health and confined to a rest home so he gave me the reg. When I got the 1st stage apart I could see the crown block was highly corroded so he must have gotten water in there somehow; otherwise, the reg looks like it just came out of the showroom. Fortunately I have a good supply of NOS crown blocks so now the reg is good as new (after replacing all the soft parts except for the main 2nd stage diaphragm). The 2nd stage diaphragm looks like maybe it was left in the heat a tad too long so if I ever run across a replacement diaphragm I'll swap it out for the original. Still works though. M

 

[ND5342]

Good find and nice job. However I may be mistaken but is that first stage a polished chrome? I thought the Conshelf 20 first stage used more of a satin finish like the first generation Titan that followed the Conshelf series.

 

[Scuba Lawyer]

Good find and nice job. However I may be mistaken but is that first stage a polished chrome? I thought the Conshelf 20 first stage used more of a satin finish like the first generation Titan that followed the Conshelf series.

All I know is that the yoke knob and the 2nd Stage cover say "Conshelf 20" on them. You may be correct, but the one I have is all shiny chrome. I like shiny things.

 

[ND5342]

All I know is that the yoke knob and the 2nd Stage cover say "Conshelf 20" on them. You may be correct, but the one I have is all shiny chrome. I like shiny things.

I don't blame you...shiny chrome is addictive!

 

[GJC]

...I just sold (damn near gave away) a yeller one just like that. If I had known you were into those I'd have sent it to you.

View attachment 612374 View attachment 612375

You should send it to him. He should have a matching octopus, no?