I posted this over at VDH but it needs to be here as well. There are several members here whom took the time to help me bring my Hydro Twin II back to life and I am extremely grateful. When people take time out of their lives to pass on tips, advice, knowledge and parts they deserve to be recognized. John Ratliff, Jerry Lang, Charles Notthoff along with Allan Klauda, The Scuba Museum and Bryan at Vintage all helped and I am thankful.
Last Edit: Aug 3, 2017 17:28:06 GMT -8 by thomas8294
Aquala, I am not sure of the manufacturing date as the label came to me as a reproduction and I could not find any other serial numbers to try and base it off of. Everything that I have seen so far seems to point to the years 63'-69' but that is as close as I can narrow it down. I will say we put it on the bench last night and it held 140 for about 20mins and dove very nicely but that was only to 8ft!
Hello: Is there any service manuals out there on the Internet for the Hydro twin II? I just recently purchased a Hydro twin II, You can just barely read the serial numbers on the label of 02848. I hooked it up to one of my tanks and it's leaks air. Last week in Searat showed me how to open up the Hydro twin and take out the first stage seat and the high pressure diaphragm which helped. It would really be nice if there was some service manuals out there on the Internet that we could look at. I know parts are really Scarce for these regulators but I did manage to pick up a new NOS diaphragm which is still in new condition. Next I just need to take a closer look at the first stage seat and see if that is still in good enough condition to use. Marion
Nikeajax, The seat and plunger on mine are different then the ones you have pictured. I don't have a third party host to hold my photos or I would try to link one to show you what I have but needless to say it is different. ScubadiverBob mentioned to me awhile ago that Sportsways put three different seats and I will assume plungers in these regs. I wish I had more info but I did get the help I needed here from those I mentioned earlier.
Thanks for the compliments; that is the original label on my Hydro Twin, and I haven't been too careful with it either. Because it is recessed, it seems to last well.
A couple of things when you tear this regulator apart. The first stage is a balanced design, which means there are several O-rings that need lubrication and/or replacement (though I have not needed to replace mine). This may be a source of more resistance too. I had a hard time getting the HP pin out. I may have also tried to get the HP diaphragm out too; I cannot recall. What I did was to decide to use high pressure air from a tank to do so--DON'T DO THAT! When I put the HP air onto the partially disassembled regulator, that pin was blown to the ceiling with amazing velocity. It took me about twenty minutes to find it on the cement floor. But if my head had been in the way, it would not have been pretty.
You mention that you have a different diaphragm on this regulator. Realize that the original diaphragm probably is a pretty good one, and may only need some silicone grease to restore it. There are four rivets on the original diaphragm, and a small tab at a 45 degree angle from the rivets. That tab is meant to fit over the center of the mushroom exhaust valve to keep the diaphragm from pushing the exhaust valve shut if you loose the intake non-return in the mouthpiece. I found out about this characteristic of mushroom valve double hose regulators on the second generation Healthways Scuba regulator, which lack this tab. I tried using it without a mouthpiece mushroom valve for easier breathing, and found that I could not exhale through it. For that regulator, I glued a nut onto the exhaust case just above the moushroom, and that fixed the problem. Sprotsways anticipated this problem and put the tab on the diaphragm (Healthways, on their Gold Label Scuba double hose regulator, put a tab on the exhaust case).
I don't have my IP gauge available (kind of misplaced it somewhere), so I don't know the IP of my Hydro Twin. I do have a Sportsways Sport Diver II regulator (same first stage, downstream second stage), and i put that regulator on the tank and it was breathing fine. I then mounted the Sport Diver II on my Hydro Twin, and it free flowed very badly, so I have the IP set very high on the Hydro Twin. But at that setting, the regulator have great venturi, and I can initiate flow and pull it out of my mouth and it continues flowing. I need to exhale to stop it. One thought I have is that there is a hex nut over the LP assembly, and I have mine tightened all the way down. This may be a means of lessening the spring tension by unscrewing that nut until the spring tension matches the interstage pressure. I don't know that for certain, but may try it tomorrow evening just to see. It does not seem to need to be tightened all the way down for sealing purposes, but this will be an experiment.
Concerning the opening for the second stage, it is the large opening that is to be pointed down the intake hose. The small opening goes back into the case.
The Sportsways Hydro Twin is a great regulator, and I have had it to about 50 feet in the North Umpqua River. It probably cannot out-perform a RAM (or Mossback Mk 3, or Phoenix) because of internal openings and design, but it is close, and way ahead of the RAM time-wise. I understand that legal action (or the threat of such) from US Divers made Sportsways discontinue this ingenious double hose regulator. It is still the only one to utilize its design to decrease the height of the regulator above the valve, which cuts off about 2 inches of water pressure differential between the regulator and the diver's lungs, making it easier to breathe by 2 inches of water without any mechanical adjustments. Here's a few more photos of mine: vintagescuba.proboards.com/thread/2654/tuning-sportways-hydro-twin?page=1&scrollTo=19826
Marion, if your soft-seat is more like the US Divers or Dacor, you may be able to polish it out: I have done so VERY successfully with both kinds. I put some masking tape on the shaft, then lock it down, GENTLY, in a drill's chuck, then lock that down in a vice. With a bit of 1500 wet-dry paper, gently touch it to the rapidly spinning seat: it doesn't take much. I tried this with a POS-Voit seat: the material they used gets very brittle over time and he high pressure blew it all to pieces when I put it back together, as I said, POS!
Marion, before trying any polishing, lubricate the internal O-ring I showed you, as that is the most likely source of the leak. The seats are usually in pretty good shape. But this O-ring is a dynamic O-ring, which means the shaft of the seat plunger moves with each breath, and each time to turn on or turn off the air. That translates into a more rapid wearing, or drying, of this O-ring than any of the other Orings.
Post by Seahuntjerry on Aug 6, 2017 8:13:53 GMT -8
The 1964 Hydro Twin 11 is a completely balanced first stage.The parts for the dual air will Not work period.Sportsways made 2 different styles of Hp seats for this regulator. I just Sold Paul the parts that corrected his intermediate pressure leak.
For "pizza mind" (peace of mind) I'd replace the o-ring: lubing it up might bring it back to life, but how long has it been in there, and how much long might it last--if it fails then you get to string out chains of four letter words trying to figure it all out again--YIKES! Get a strong magnifying glass and inspect the soft-seat where it comes into contact with the hard-seat: if you find anything in that landing-area, and it doesn't take much at all, you may have damaged seat, smaller than that of the diameter of a human hair...