Yawana Dive
Regular Diver
Diving the Solomon Islands
Posts: 45
|
Post by Yawana Dive on Jun 11, 2021 10:39:58 GMT -8
Yep that makes sense JB
I’ll take this thing apart today and post some pics. I’ll try to get a close up photo of the HP soft seat before I attack it with the Makita and clam shell.
Andrew
|
|
|
Post by herman on Jun 11, 2021 12:03:02 GMT -8
I am not familiar with the Navy but looking at my service manuals, some questions come to mind. First off, every Navy I see has a J valve, does yours? If so, then the SPG moving with your breath is normal with a properly functioning J valve in the "dive" position. I would expect some IP change as the tank pressure drops but I would think more in the 20-30 psi range, not 70. If I had to guess, I suspect a bad HP diaphragm or spring.
|
|
|
Post by james1979 on Jun 11, 2021 12:44:27 GMT -8
I’ll try to get a close up photo of the HP soft seat before I attack it with the Makita and clam shell. Not a particular help, but I just wanted to say that I love this forum..... Where else can you say something like that and nobody batts an eye!
|
|
Yawana Dive
Regular Diver
Diving the Solomon Islands
Posts: 45
|
Post by Yawana Dive on Jun 11, 2021 18:04:18 GMT -8
I am not familiar with the Navy but looking at my service manuals, some questions come to mind. First off, every Navy I see has a J valve, does yours? If so, then the SPG moving with your breath is normal with a properly functioning J valve in the "dive" position. I would expect some IP change as the tank pressure drops but I would think more in the 20-30 psi range, not 70. If I had to guess, I suspect a bad HP diaphragm or spring. Yes Herman it’s got a J valve but it doesn’t really seem to work. I’ve pulled it apart and the Jvalve seat and parts are all there and look to be in good shape, but I’ve dived with it in the down position until the tank was almost completely empty (100psi) and the breathing effort remains the same. I’m assuming it’s not working.
|
|
|
Post by herman on Jun 11, 2021 18:12:25 GMT -8
Well, the dipping of SPG while breathing is normal for a J valve in the dive position so maybe it decided to start working. Easy enough to tell, put it in dive, check to see what it does and then change to reserve and see what happens (should NOT have a SPG swing in reserve mode.
|
|
|
Post by cnotthoff on Jun 11, 2021 18:22:18 GMT -8
I am not familiar with the Navy but looking at my service manuals, some questions come to mind. First off, every Navy I see has a J valve, does yours? If so, then the SPG moving with your breath is normal with a properly functioning J valve in the "dive" position. I would expect some IP change as the tank pressure drops but I would think more in the 20-30 psi range, not 70. If I had to guess, I suspect a bad HP diaphragm or spring. Yes Herman it’s got a J valve but it doesn’t really seem to work. I’ve pulled it apart and the Jvalve seat and parts are all there and look to be in good shape, but I’ve dived with it in the down position until the tank was almost completely empty (100psi) and the breathing effort remains the same. I’m assuming it’s not working. The down position is normally the reserve position, as in the reserve mechanism is pulled back allowing all the air in the tank out. Almost all reserve mechanism work like a couple of knuckles pressed against each other. Rotating the stem 90° pulls the seat back. It's possible to assemble the reserve so that the dive position is down, but that will confuse most divers. When you are reassembling the valve, test it by blowing through the dip tube while the on/off knob is open all the way. Operate the reserve lever as you're blowing. Unless you've got some mighty powerful lungs, you won't be able to pass air with the reserve in the dive/up position. Good Dives, Charlie
|
|
|
Post by SeaRat on Jun 11, 2021 19:18:04 GMT -8
I'd like to clear up some "Sportsways Confusion" here. I have a Sport Diver, which has the same first stage with the J-valve. When the reserve lever is up, you have a restriction that saves about 300 psi of air in the tank. When it is down, there is not restriction, and therefore no reserve. But Sportsways, in their infinate wisdom, placed this ingraving on their valve.
.....OFF..... START DIVE .......| .......V ON OR FILL
So you start the dive with the reserve lever up, in the "OFF" or "START DIVE" position. This ensures that 300 psi will remain in the tank when you think you've run out of air. By pulling the J-lever, or using your hand to move the lever to the down position, you magically have another 300 psi of air to surface with.
You can test this another way, and that is to put the mouthpiece into your mouth, and with the lever up, try to inhale (no tank). Air will not flow through the regulator. Now put the lever in the down position, and inhale, and you can hear air coming through the sintered filter on the first stage. So in order to have a reserve, you need to have that reserve lever in the up "START DIVE" position. Sportsways feels that the reserve is "ON" when you can breath through it.
Other manufacturers state it in the opposite manner, that the J-reserve is "ON" when the lever is up, indicating that you have a reserve awaiting you to trip the reserve lever.
John
PS, my inverted arrow above is what is engraved on the first stage, but doesn't look nice above.
|
|
Yawana Dive
Regular Diver
Diving the Solomon Islands
Posts: 45
|
Post by Yawana Dive on Jun 11, 2021 20:22:30 GMT -8
I’m sorry to sow confusion. I meant to say I dived it with the lever in the up position until the tank was low and didn’t notice any breathing resistance. Unlike my Healthways Scubair which really lets me know when it’s time to be heading back to the homestead. Here’s the Navy Unit 1st stage disassembled. The HP seat is quite different from the Hydronaut I was working on earlier. It doesn’t have the ‘balance chamber’ gizmo behind the spring. This is probably an earlier model. The seat appears to be in very good shape examining it under a magnifying glass, so I haven’t take a close up photo as there really isn’t anything to see. So I’m thinking the problem must be the diaphragm. I’ve got a new SP diaphragm from a Mk11 kit I’ll trim and fit and see if I don’t blow the roof off the workshop. 3A1C4834-F7F9-4329-BC4C-A56807D7BA3C by Andrew Trahair, on Flickr
|
|
|
Post by snark3 on Jun 11, 2021 22:45:26 GMT -8
Andrew the parts you have in the picture above are the same as what I found in my Hydro Twin I, which is an unbalanced first stage
|
|
Yawana Dive
Regular Diver
Diving the Solomon Islands
Posts: 45
|
Post by Yawana Dive on Jun 11, 2021 23:28:05 GMT -8
Weeeeell... that didn’t fix the problem. Changed the diaphragm and there’s still 30psi ip difference between a full tank and an empty one. So it must be the seat - but it looks brand new! Snark3 - do you have such a huge shift in ip with your Hydro Twin I ? Could this be how things are? Perhaps the HP seat spring is faulty? Lost some of its mojo?
Hmmmm...... thinking......
|
|
|
Post by snark3 on Jun 12, 2021 0:57:30 GMT -8
Weeeeell... that didn’t fix the problem. Changed the diaphragm and there’s still 30psi ip difference between a full tank and an empty one. So it must be the seat - but it looks brand new! Snark3 - do you have such a huge shift in ip with your Hydro Twin I ? Could this be how things are? Perhaps the HP seat spring is faulty? Lost some of its mojo? Hmmmm...... thinking...... I don't remember ever checking the Sportsways. I'll put it on a couple of tanks today and check it.
|
|
|
Post by herman on Jun 12, 2021 4:00:30 GMT -8
If you now have the IP swing in the 30 psi range (high at low tank pressure and lower at high tank pressure) I would think that is normal for that reg. Remember this is an unbalanced reg. A DAAM which is also an unbalanced diaphragm reg swings around 20-25 psi and with the different seat design 30 psi doesn't surprise me. At this point I think you are trying to fix something that is not broke.
|
|
|
Post by nikeajax on Jun 12, 2021 8:13:33 GMT -8
Andrew, those HW/SW HP diaphragms are VERY robust, and don't usually go bad: if you do replace it, you need to make sure it's the correct thickness.
Did you try the test I suggested? That should be the first place to start.
JB
|
|
|
Post by snark3 on Jun 12, 2021 10:20:01 GMT -8
OK guys as promised I put my Hydro Twin I on some tanks today. Tank 1 2200 PSI - IP 105 Tank 2 1300 PSI - IP 130 Tank 3 200 PSI - IP 160
|
|
Yawana Dive
Regular Diver
Diving the Solomon Islands
Posts: 45
|
Post by Yawana Dive on Jun 12, 2021 11:07:54 GMT -8
Ok, so I’m thinking I’ve reduced the ip swing by replacing the diaphragm, and that’s good enough. If 30psi swing is normal then I’m happy with that. The reg performance is just fine for my needs.
JB, I did as you suggested and turned on the air after I removed the diaphragm. Nothing happened. I was a bit hesitant to start poking things down the pin hole to see if the HP seat was doing it’s job as I didn’t want to damage anything. I sure wasn’t going to use the tiny pin in case it went flying across the room. (Then I would be in the throws of cursing that damned Jaybird!) So I swapped out the diaphragm and reassembled the reg and that’s where things are now. The rubber of the SP diaphragm I used is a tiny bit thinner than the Sportsways original but definitely more flexible. Surely that would improve performance a bit? Either way I’m happy with things if the ip swing is in the acceptable range for a non balanced diaphragm regulator.
Now it’s time to get it wet again....
Thanks again for the interest, input, advice and suggestions.
Cheers
Andrew
|
|