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Post by vance on Apr 20, 2022 14:43:22 GMT -8
The one with the drill bit shaft doesn't work well. I believe the blue puck is too soft and doesn't allow enough opening for airflow. The originals use a material that is quite hard. The HW seat looks as if it's made out of a chunk of plastic, without a metal cup. Anyone know of a harder rubber to use? This might be a good place to use a hardened old seat, if it has a good side! Rather than harder material, what if you use thinner material (shave the blue puck down)? Same hardness, less total give, may work? That might work, but was trying for a simple, replaceable solution. Punching some harder, thinner stuff to use in a thinner cup could do 'er. But what stuff?
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Post by vance on Apr 20, 2022 14:50:17 GMT -8
I tried machining a DA HP seat for this project, but the flat separated from the shaft when I turned the spring seat down to match the tilt valve's cone. It was close to the size needed for the conical spring, but not quite there when it separated.
Turns out, the nylon (or whatever) seat is the same thickness as the flat. Got me to thinking one could replace the seat material....
Has anyone tried that?
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Post by antique diver on Apr 20, 2022 14:50:21 GMT -8
Installed and tested the Aqualung HP seat conversion to tilt valve. It was the easiest to make and can be done without a lathe by careful cutting or filing the outer diameter to same dimensions as the original tilt valve. Seals up fine and hopefully will work for a long time.
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Post by vance on Apr 20, 2022 14:55:49 GMT -8
James, you've got the right idea, as the original material was, I'm guessing, about 1/3 the thickness JB But they seem much harder. The used valves I have show very little indentation, and when prodded, have much less give than a blue puck. Maybe the hardness is due to age, but I believe the original seat material was harder than the usual stuff.
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Post by vance on Apr 20, 2022 15:04:22 GMT -8
Installed and tested the Aqualung HP seat conversion to tilt valve. It was the easiest to make and can be done without a lathe by careful cutting or filing the outer diameter to same dimensions as the original tilt valve. Seals up fine and hopefully will work for a long time. Looks great! I hope this helps those who need a tilt valve in future. Nice work, Bill! It's been really great to have you on the board, pushing us to do interesting stuff!
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Post by nikeajax on Apr 20, 2022 15:24:17 GMT -8
OK... what about... PVC? Or, or, the stuff they use for blister-packs? Just brain storming, eh?
JB
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Post by vance on Apr 20, 2022 15:50:55 GMT -8
What about a 90 duro 1/16" silicone sheet? Maybe even a higher duro #? Suggestions?
I like Bill's HP seat mod a lot. This is the answer to those who need a relatively inexpensive tilt valve, and don't have machine tools.
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Post by vance on Apr 23, 2022 14:56:31 GMT -8
I tried machining a DA HP seat for this project, but the flat separated from the shaft when I turned the spring seat down to match the tilt valve's cone. It was close to the size needed for the conical spring, but not quite there when it separated. Turns out, the nylon (or whatever) seat is the same thickness as the flat. Got me to thinking one could replace the seat material.... Has anyone tried that? I know. Quoting myself again. I punched the nylon? seat out of the flat section. It didn't give up its secrets easily. It got a bit deformed, but appears to be a barbed nylon? cylinder that is driven into the seat. It seems to have 2 angled cuts in the side that will resist coming out of the bore. This might need a new thread, if it has legs.
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Post by vance on Apr 23, 2022 15:18:49 GMT -8
Installed and tested the Aqualung HP seat conversion to tilt valve. It was the easiest to make and can be done without a lathe by careful cutting or filing the outer diameter to same dimensions as the original tilt valve. Seals up fine and hopefully will work for a long time. Just to clarify: You removed the flat, then turned the od of the seat part to size. Then, you drilled into the pin bore a little ways with a #53 bit, and drove a section of 1/16" stainless rod into the cup? If so, this is the One. Keanu would be proud! Kudos, Bill!
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Post by antique diver on Apr 23, 2022 18:39:33 GMT -8
Installed and tested the Aqualung HP seat conversion to tilt valve. It was the easiest to make and can be done without a lathe by careful cutting or filing the outer diameter to same dimensions as the original tilt valve. Seals up fine and hopefully will work for a long time. Just to clarify: You removed the flat, then turned the od of the seat part to size. Then, you drilled into the pin bore a little ways with a #53 bit, and drove a section of 1/16" stainless rod into the cup? If so, this is the One. Keanu would be proud! Kudos, Bill! Phil, Your description of the process is correct. Pretty simple compared to the other things I tried.
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Post by antique diver on Oct 20, 2022 6:04:08 GMT -8
This is not about tilt valves as such, but about a critical component of the first stages that feed tilt valve second stages... the important relief valve. I have tended to neglect testing and servicing those since I haven't taken one of those regs for a dive in many years, but recently putting a Healthways Scuba Star in diving condition I wanted to be sure the relief was working. It wasn't. It didn't leak, but the seat was stuck shut and did not relieve even when tested on higher than normal pressures. That condition could leave to a ruptured hose if the HP seat was not holding.
I decided to test 5 of the relief valves from vintage regulators, and 4 new/unused ones that I have had in stock for about five years. Some of older ones were stuck shut, and all the others seeped air at almost any IP. All four of the new ones leaked badly due to badly deteriorated seats that must have been made in China from melamine and pig poop. Shown here is how I am attempting to make new seats for the simply made reliefs: Testing the rebuilt valves gave various results, but the seats had to set in under spring tension for a day or two to give a good seal. Adjusting them to appropriate relief pressure was done with a specialized regulator that can be finely adjusted in 1 psi increments from zero to 3500. This wasn't a simple as I had hoped because some of the older springs seem to have lost some of their tension over time. I could get a fairly good adjustment on some of them to start relieving at 150 psi and going full blast by 200 psi, so that should work out ok on the Scuba Star and the Sportsways. I'll test again after they sit for a week or two.
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Post by nikeajax on Oct 20, 2022 8:19:58 GMT -8
Bill, thank for sharing that with us. It would indeed be a good idea for those of us with tilt-valve to service them: I have I think four or five regs that use them, most are Scuba Stars, but I do have a first gen Scubair too! JB
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Post by SeaRat on Oct 20, 2022 12:11:30 GMT -8
[quote author=" nikeajax" source="/post/55524 /thread" timestamp="1666282798"] Bill, thank for sharing that with us. It would indeed be a good idea for those of us with tilt-valve to service them: I have I think four or five regs that use them, most are Scuba Stars, but I do have a first gen Scubair too! JB[/quote] Fred Roberts, in Basic Scuba, talks about adjusting the ORV on tilt valve regulators, and states that you should put the regulator on a tank, at full pressure for piston first stages, and turn the adjusting nut out until the air leak starts, then in just a bit (1/4 turn), just enough so it doesn’t leak at full tank pressure. For diaphragm first stages (original Healthways Scubair), this should be done at low tank pressure, as the interstage pressure varies inversely with the tank pressure on diaphragm first stages. On piston fist stages, it varies directly, and so the IP is highest at full tank pressure with a piston first stage. John
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Post by antique diver on Oct 20, 2022 14:07:21 GMT -8
[quote author=" nikeajax" source="/post/55524 /thread" timestamp="1666282798"] Bill, thank for sharing that with us. It would indeed be a good idea for those of us with tilt-valve to service them: I have I think four or five regs that use them, most are Scuba Stars, but I do have a first gen Scubair too! JB With me having two copies of BASIC SCUBA you would think I should remember to check there on stuff I wasn't sure of. I was just flying untrained on the relief valve adjustment, but I did notice that the adjustments were not linear, and sometimes not repeatable at a given setting! So I just did what seemed ok for me.
Thanks for the info!
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Post by nikeajax on Oct 21, 2022 17:18:59 GMT -8
Bill, you could also hook them up to the first stage of diaphragm reg set the IP to 150, then adjust it to where it just stops to free flow... JB
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