Snark III Navy...
- Since the United States Navy Seals use Snark III regulators for training, I decided to give this Snark III Silver I've been working on a "USN" mouthpiece. I bought a nice green curved one and gray hoses from Rob's Scuba Museaum. (Apologies for the photo quality, I finished it late last night.)
- This is the St. Vincent's regulator I've shown here previously. I was going to test dive it at the public pool but when I checked the IP with my home made IP gauge, the needle appeared to move really fast to high pressure and looked like it wasn't stopping until I turned off the air. I took it to the pool for submersion to see if the over pressure valve was leaking... And it wasn't. So, I set the reg aside for further thought, consideration, and repair.
- My first thought was that the high pressure seat was leaking. But if that was the case, the OPV should have been releasing bubbles. So then I thought "Maybe the IP is just set too high". I have two other working Snark regulators so I checked their IP to see what is normal. They were both dead-on set to 150 psi when mounted to a 300 psi tank. But when I checked this Snark III Navy, the IP was set to nearly 200 psi (175 actually) and the gauge only goes up to 200 so that's why it looked like it was going off the chart when I turned on the air.
- Long story short, I adjusted the IP to 150 like the other two Snark IIIs and it held dead-on steady and returned to that setting through several tank turn-ons and lever pushes. So, the HP seat isn't leaking and I think I'll leave well enough alone there. And the OPV isn't leaking either... But I noticed the OPV was adjusted right down to the highest pressure stop point... Worth noting. But everything is working and looking great so I closed up the patient and installed the new hoses and mouthpiece.
- Now this morning I found my PDF copy of the Snark III Silver service manual and was able to look up some proper settings: The IP is supposed to be 125 psi when attached to a 500 psi tank. Furthermore, the OPV is supposed to release when IP goes over 150 psi. So, I've got a littleways to go before I have this Snark III Navy all set up perfectly... Same with my other Snark IIIs. But at this point they are all breathing easily, consistently, and smoothly.
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Snark III Silver vs Older Snark IIIs
- My older Snark IIIs are very similar to DA Aqua Master regulators in the 1st stage. The nozzle unscrews to reveal an almost identical 1st stage system. On this new Snark III Silver, my attempt to remove the nozzle gave me nothing more than a nut and yoke... The nozzle is integral with the regulator body. The diagram in my Snark III Silver service manual does not show this arrangement... It still shows the removable nozzle.
- And, the Snark III Silver has an HP port for a pressure gauge where the older regs do not.
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How to Adjust the OPV and IP...
- I've been thinking on this and its explained in the service manual. First you adjust the Interstage Pressure (IP) to 150 psi. Then you adjust the the Over Pressure Valve (OPV) to release at the 150 psi IP setting. Finally, you re-adjust the IP back to 125 psi when mounted to a 500 psi tank. Stay tuned!