First full regulator rebuild under my belt.

[TN-Steve]

I'm rather pleased with myself. I started off with a Dive Rite 1208 First and a 2015 balanced adjustable second stage I got off of ebay. (supposedly had been serviced and was in good condition).

I think that the seller was a bit "optimistic" regarding their condition.

The 1208 blew past 180 psi intermediate pressure on the test bench before I managed to shut off the air supply. And I don't mean it was slowly drifting, that needle was still screaming.

The second stage, when attached to a good first, just wouldn't seal.

Figured I had my hands full, but armed with a couple of rebuild kits and the manuals I took to it.

The first was so corroded at the ambient end that I had to use PB Blaster and let it sit for 48 hours to take it apart. The spring was absolutely caked with white stuff.

Everything got ultrasonic cleaning in hot soapy water, good toothbrushing, then rinsed, and then any parts that really needed it got 3 minutes in the cleaner in a vinegar solution, and the same treatment. Rinse and dry.

Took me a lot longer to get it apart than to put it back together. (I made sure to take plenty of pics and taped o-rings to a piece of cardboard so I could correctly identify the right one come reassembly.

End of the day, I've got a reg that's holding 140 IP like a champ, that is cracking at 1 inch, (wish I could get it lower, but I'm happy with that), and on the flow meter with the lever in dive mode is sitting about 1.1 inches all the way up to 12.5 SCFM.

All in all, it was easier than I had expected, and considering what I started with, I'm pretty well pleased. I'll mate it up with one of my 1215 octos (Haven't rebuilt them yet, waiting on the kits to come in, but they work fine already) and dive it this coming weekend for my Rescue Diver class.

Looking forward to getting lots of good info here as I continue my trek toward "Equipment Repair Guy"

Steve

 

[victorzamora]

Congrats! That's a big deal!!

 

[Bob DBF]

Congratulations and welcome to the dark side.



Bob

 

[Jim Lapenta]

Depending on the seat material you may find that the 1 inch cracking pressure may drop a little after a couple dives as the seat gets a groove set in it.

 

[axxel57]

Congratulations and welcome.

One question.

Are you sure about your measurements concerning the Flow Test?

I have done over years more than two thousand Flow Tests, but I never had a case where the dynamic IP drop would translate only in 0,1 inch/O2 increased inhaling effort and be stable over the whole course of the test up to 12,5 SCFM.

The minimum I know is 0,3inch/O2 increase and this would not be stable,but starting to drop when the Venturi kicks in.

You can end up at almost any cracking effort at 12,5 SCFM depending how the Venturi is working on that particular 2nd stage, but that a cracking effort is just increasing by 0,1inch/O2 and then staying stable at the same level, is very unlikely.

With the increasing airflow the lever of the 2nd stage has to open more and more to be able to flow that high amount of air. While doing so the spring in the 2nd stage is more and more compressed, increasing normally the cracking effort until the Venturi kicks in which often is so strong that it overrides the spring pressure and the cracking effort drops under 0inch/O2, means sort of free flowing.

It is theoretically possible that the Venturi kicked already in when the cracking effort had just increased by 0,1inch/O2 and then kept the cracking effort at that level while the airflow was increased from 0 - 12,5 SCFM, but I have never seen that yet.

Which Flow Tester are you using?

 

[TN-Steve]

I'm about as positive as I can be with them. I ran it with the venturi in both dive and pre-dive settings. In pre-dive it was a steady progression up to about 4.5 inches at 12.5 CFM. In dive mode, it pretty much held steady all the way across the board. I didn't believe the numbers myself, so I ran the test a second time, same thing.

The flowmeter / test bench is the one from Scubatools.

Anything you can do to enlighten me would be most appreciated. Since I'm new at this, I don't have that "sense" of what readings would be questionable. The shop owner looked at my sheet and just said "Looks like it's breathing good".

Steve

Congratulations and welcome.

One question.

Are you sure about your measurements concerning the Flow Test?

I have done over years more than two thousand Flow Tests, but I never had a case where the dynamic IP drop would translate only in 0,1 inch/O2 increased inhaling effort and be stable over the whole course of the test up to 12,5 SCFM.

The minimum I know is 0,3inch/O2 increase and this would not be stable,but starting to drop when the Venturi kicks in.

You can end up at almost any cracking effort at 12,5 SCFM depending how the Venturi is working on that particular 2nd stage, but that a cracking effort is just increasing by 0,1inch/O2 and then staying stable at the same level, is very unlikely.

With the increasing airflow the lever of the 2nd stage has to open more and more to be able to flow that high amount of air. While doing so the spring in the 2nd stage is more and more compressed, increasing normally the cracking effort until the Venturi kicks in which often is so strong that it overrides the spring pressure and the cracking effort drops under 0inch/O2, means sort of free flowing.

It is theoretically possible that the Venturi kicked already in when the cracking effort had just increased by 0,1inch/O2 and then kept the cracking effort at that level while the airflow was increased from 0 - 12,5 SCFM, but I have never seen that yet.

Which Flow Tester are you using?

 

[axxel57]

I'm using a GMC Flow Module, so I cannot compare your tester really with mine, it's just puzzling me that you were able to conduct a flow test in which the increasing cracking effort is exact compensated by the increasing Venturi.

Did you notate the dynamic IP at 10 SCFM?

Would be interesting to read if you would have in future flow tests similar results.

Anyway, it's nice to have somebody new and enthusiastic in the DIY section like you.

Again, congrats and I hope to hear more from you in the future.

 

[TN-Steve]

I was pulling the numbers off my head, I may have been a bit optimistic, I've got the test sheet in front of me now.

Static IP was 138 at both 500 and 3000 psi, no drift

MAX Venturi

• Static Cracking: 1.1 In/H2O
• 5 SCFM: 1.4
• 7.5 SCFM: 1.1
• 10 SCFM: 1.3
• 12.5 SCFM: 1.2

MIN Venturi

• Static Cracking: 1.1
• 5 CFM: 1.8
• 7.5 CFM: 2.8
• 10 CFM: 3.5
• 12 CFM: 4.0

Dynamic IP pressure at 10 CFM was 130 PSI,
same reading for both venturi ON and OFF. (Which I "Think" would make sense, since the first stage is simply supplying X amount of air, it is unaware of cracking pressure / inhalation effort from the second stage. It wouldn't care if I had the end of the hose connected to a needle valve and was controlling it that way).

Do these numbers fit better into the "Common Sense Test"? Little bump at 5 CFM, and then the venturi effect really kicks in?

Thanks again for the feedback. Without experience it's hard to know if something isn't making sense, but I have to say that the copy of "REGULATOR SAVVY" went a HUGE way in helping me understand the "How and Why" and the the interactions / relationships between the various elements.

Here is the test equipment at the shop I'm in A.I.R. Flow Analyzer, Four SpinOns, & Floating Wall Bracket Assy They also have the HP Manager, so I can dial in any pressure to the first stage from 0 to whatever is in the bank tank.



Steve

I'm using a GMC Flow Module, so I cannot compare your tester really with mine, it's just puzzling me that you were able to conduct a flow test in which the increasing cracking effort is exact compensated by the increasing Venturi.

Did you notate the dynamic IP at 10 SCFM?

Would be interesting to read if you would have in future flow tests similar results.

Anyway, it's nice to have somebody new and enthusiastic in the DIY section like you.

Again, congrats and I hope to hear more from you in the future.

 

[axxel57]

I was pulling the numbers off my head, I may have been a bit optimistic, I've got the test sheet in front of me now.

Static IP was 138 at both 500 and 3000 psi, no drift

MAX Venturi

• Static Cracking: 1.1 In/H2O
• 5 SCFM: 1.4
• 7.5 SCFM: 1.1
• 10 SCFM: 1.3
• 12.5 SCFM: 1.2

MIN Venturi

• Static Cracking: 1.1
• 5 CFM: 1.8
• 7.5 CFM: 2.8
• 10 CFM: 3.5
• 12 CFM: 4.0

Dynamic IP pressure at 10 CFM was 130 PSI,
same reading for both venturi ON and OFF. (Which I "Think" would make sense, since the first stage is simply supplying X amount of air, it is unaware of cracking pressure / inhalation effort from the second stage. It wouldn't care if I had the end of the hose connected to a needle valve and was controlling it that way).

Do these numbers fit better into the "Common Sense Test"? Little bump at 5 CFM, and then the venturi effect really kicks in?

Thanks again for the feedback. Without experience it's hard to know if something isn't making sense, but I have to say that the copy of "REGULATOR SAVVY" went a HUGE way in helping me understand the "How and Why" and the the interactions / relationships between the various elements.

Here is the test equipment at the shop I'm in A.I.R. Flow Analyzer, Four SpinOns, & Floating Wall Bracket Assy They also have the HP Manager, so I can dial in any pressure to the first stage from 0 to whatever is in the bank tank.

View attachment 206701

Steve

Yeah,well that is quite something different and much more normal.

Usually is the Venturi increasing with the higher laminar air flow, lowering the cracking effort continuously,but it is also relatively common that the cracking effort increases in between a bit before lowering again.

The only 0,3 increase is pretty excellent,but it makes sense in comparison to the 0 increase you were writing about before.

The 8psi drop of the dynamic IP is good, but not excellent,but a 0 difference in the static IP at 3000 psi and 500 psi is unusual.

I see this only sometimes on Legends and, strange enough, on Mares MR12 once in a while.

Normally should the IP be at low tank pressure higher in those diaphragm types.

I have never seen that on Dive Rites, but my experiences with the Dive Rites are limited (just around 15 services or repairs over the years), so I don't know really.

Thanks for sharing your numbers, if you ever should come across with weird numbers in your future tests, you can contact me, I have a pretty big data bank with lots of models and brands tested for comparison.