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antique diver
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Re: RIX SA3E

Fri Aug 26, 2016 7:36 pm

SurfLung wrote:I have a NEW Issue with my RIX SA3E...
- After servicing the 3rd stage head, I've pumped quite a few tanks just fine and I think it has even been pumping a little faster than it used to.
- But recently, it takes a little while for the compressor to start building pressure. When I switch it on, I can hear a leak for a little while and it doesn't build pressure. Then the leak stops and the pressure builds normally.
- The leak sounds like it is coming from the open bottom of the third stage cylinder. The manual says the 3rd stage piston is the one that needs new rings more frequently. I'm thinking the newly serviced cylinder head is sealing so well it may have put just enough more pressure load on those well worn 3rd stage rings to push them into overhaul condition?
- The compressor seems like it leaks until it warms up enough to seal the leakage. Once, opening and closing the 3rd stage moisture valve seemed to flick it to stop the leaking. Other times it just has to run awhile and then it seals.
I think you could be right about the blow-by being air passing worn rings. While I have a Rix, I don't have any experience with worn rings yet... but in conventional oiled compressors there can be be more blow-by until the machine warms up and parts expand some.

Another cause for leak you hear could be a leaking tubing or pipe fitting that seals up somewhat for the same reason - from expansion of the parts upon warmup. As you know, the source of even an audible air leak is often very difficult to discern!

You probably did not cause the problem by servicing the head valves and seals... could just be time is up on the rings, or you have another leak source.
The older I get the better I was.

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SurfLung
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Re: RIX SA3E

Mon Aug 29, 2016 1:15 pm

Thanks Bill! I'll re-check the fittings... That'd be nice if I just have to tighten something up. Otherwise I'll be planning to re-Ring the 3rd stage.
SurfLung
The Freedom and Simplicity of Vintage Equipment and
Vintage Diving Technique are Why I Got Back Into Diving.

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SurfLung
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Re: RIX SA3E

Thu Dec 15, 2016 11:36 am

Update on Re-Ringing my RIX...
- I was able to keep filling tanks until the end of our dive season by allowing my compressor to pump while leaking for a few minutes until it warmed up and sealed the leak. So now I'm getting set to re-ring the 3rd stage and I thought I'd post my progress on this forum.
- I began by reading my RIX service manual. This has proven to be very helpful with an illustration, explanation, and instructions. The third stage piston is free floating... It's not actually connected to the piston rod. It has two "Rider Rings"... one on each end plus a rider ring on the end of the piston rod. Between the two Rider Rings, there are 5 piston rings. And, each piston ring has an O-Ring Expander. Finally, there's a piston storage tube that's used to compress the rings as you insert the piston into the cylinder.
- The manual explains how the third stage rings wear out one by one and the remaining rings continue to seal until the last one gives out. Being a used machine when I bought it, I had no idea how many hours of operation were on this 3rd stage piston. Ideally, I should be re-ringing it before all 5 rings give out and it starts leaking... Like it is leaking now!
- I ordered new Rider Rings, Piston Rings, O-Ring expanders, and a Piston Storage Tube from RIX. Cost was $218. I'll try and take some photos as I do this bit of re-ringing service. Hopefully I'll do it right and have my compressor running like new for next Spring.
Image
SurfLung
The Freedom and Simplicity of Vintage Equipment and
Vintage Diving Technique are Why I Got Back Into Diving.

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antique diver
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Re: RIX SA3E

Thu Dec 15, 2016 8:56 pm

Eben, I'm looking forward to following your rebuild adventure. I'm sure it will help me be better prepared for working on my Rix when that time comes.
I have rebuilt two of their tiny (0.5 cfm) Oxygen generator booster pumps in fire departments, and they were mechanically pretty simple.
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SurfLung
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Re: RIX SA3E

Wed Dec 21, 2016 10:40 am

$218 Worth of RIX Stage 3 Parts...
Image
- My RIX 3rd stage re-ring parts came today. They don't look like much but there's an elegance to the simplicity. The 5 rings themselves are some sort of self lubricating Teflon material... Part of the RIX "oil-less" system. These rings are a flat spiral that compresses. Under these are simply O-Rings... I'm thinking the Teflon rings maybe don't have as strong of spring tension as steel rings, so the O-ring expanders give them an assist to ride the cylinder walls with sufficient tightness to give a good seal.
- The three "rider" rings keep the end of the piston rod and the ends of the free floating piston from having metal on metal contact when the piston rings wear out.
- The brass tube with the tapered end is called the "Piston Storage Tube"... It's actually an assembly tool. You use the tapered end to roll the O-Ring expanders into the piston ring slots. I'm not sure yet if there is a special procedure to get the piston rings into their slots. But, once they're in, you slip the whole piston into this tube to pre-compress the rings. Then you stick the tapered end into the bottom of the cylinder and push the piston into the cylinder. The whole process is intended to preserve and protect the sealing edges of the Teflon piston rings.
SurfLung
The Freedom and Simplicity of Vintage Equipment and
Vintage Diving Technique are Why I Got Back Into Diving.

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SurfLung
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Re: RIX SA3E

Tue Jan 31, 2017 4:52 pm

- I finished re-ringing the 3rd stage piston and it was so easy that I decided to send off for new ring parts for the 1st and 2nd stages. Cost was quite a bit less: $120... $60 per piston. Much less because (unlike the 5-ring 3rd stage) there is only one rider ring, O-Ring, and Piston Ring for each of these two stages. Might as well do the whole job while I'm at it. :idea:

P.S. The parts lady at RIX is Christa Aguon. She was very helpful. I asked her what a new RIX SA3 like mine would cost and she said they start at $6,000. Add another $3,000 if you want the RIX add-on filter system. Yikes. Anyway I think it is awfully nice that I can call up and order replacement parts for my $750 used RIX... And, that doing this sort of service is so easy for a do-it-yourselfer.
SurfLung
The Freedom and Simplicity of Vintage Equipment and
Vintage Diving Technique are Why I Got Back Into Diving.

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SurfLung
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Re: RIX SA3E

Fri Feb 03, 2017 2:09 pm

The Culprit...
Image
RIX SA3 2nd Stage Piston
- I hand rotated the compressor after replacing all 5 rings in the 3rd stage piston and it sounded like I was still hearing air poofs out of the bottom of either the 1st or 2nd stages. Well, changing rings on the 3rd stage was so easy, I figured I might as well spend a few more bucks and re-ring the 1st and 2nd stages. I started with the 2nd stage piston (pictured above). You can see from the photo it looks bad. Re-Ringing was easy. And after I hand rotated it with new rings, the air poofs were gone. So it was the 2nd stage piston that was the culprit.
- Surprisingly, the big huge 1st stage piston was the only one that gave me any trouble... And that was just with trying to get it back into the cylinder after re-ringing. The one big Teflon ring is kind of hard to squeeze down small enough to fit back into the cylinder. I definitely did not try to force it as the Teflon ring is quite fragile. It finally occurred to me to lubricate it with the food grade watery Trident silicone from a pump bottle and then it finally squeezed down small enough to slide into the cylinder.
- Hand Turning Test - Amazingly, 1-2 hand rotations will now build enough pressure to bleed off thru the drain valves.
- Full Power Test - Pressure now starts building immediately and fast on the pressure gauge.

I think I might just fill some tanks this weekend! :)
SurfLung
The Freedom and Simplicity of Vintage Equipment and
Vintage Diving Technique are Why I Got Back Into Diving.

swimjim
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Re: RIX SA3E

Fri Feb 03, 2017 10:38 pm

Sweet! Way to go Eben!!!!

Tommy
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Re: RIX SA3E

Sat Feb 18, 2017 6:55 pm

Can you post a drawing of how to wire in the pressure switch and relay to a standard on/off switch??
Tommy

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SurfLung
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Re: RIX SA3E

Mon Feb 27, 2017 3:07 pm

- There's a wiring diagram in the RIX SA3E manual. I received a PDF copy of the manual and the valve service guide plus a parts price list via email directly from the RIX company... Mine came from Eric Zensius. The person I have been deal with for the last couple of years is Christa Aguon. Perhaps if you contact her she can send the same documentation that I got.


Spare Parts Sales

Christa Aguon


Phone: 707.745.7177
Fax: 707.748.0398
[email protected]
SurfLung
The Freedom and Simplicity of Vintage Equipment and
Vintage Diving Technique are Why I Got Back Into Diving.

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Re: RIX SA3E

Wed May 24, 2017 10:19 am

- I've been tinkering with my RIX compressor again. The air intake filter it came with looks like a make-shift affair made out of some other filter epoxied to a compatible threaded tube. I replaced this air intake filter with a Solberg 20 micron breathing air compressor filter and discovered that it is puffing a little air OUT with each cycle. I think had a similar issue with the 2nd stage setting off the over pressure relief when the 3rd stage was leaking high pressure back to the 2nd stage. So, I'm figuring the 2nd stage is leaking high pressure back to the first stage?
- Servicing the 3rd stage head with general cleaning and new O-Rings solved the earlier issue. So, I'm servicing the other two heads. Finished Head #1 and now waiting on delivery of Viton O-Rings for #2. I don't like not being able to pump tanks, so I hope I'm back up and running by this weekend.
- The 1st stage head was pretty clean inside. But the 2nd stage head has quite a bit of soot or some other corruption.
SurfLung
The Freedom and Simplicity of Vintage Equipment and
Vintage Diving Technique are Why I Got Back Into Diving.

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Robohips77
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Re: RIX SA3E

Wed May 24, 2017 3:04 pm

I felt the same way about not being able to pump air. so I bought cascade bottles !. then I bought another compressor and then I bought more cascade bottles and then I bought a trailer. OMG I've lost my mind BUT I have plenty of compressed Air for my tanks.
First dives? 1967 and I never lost the fever.

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SurfLung
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Re: RIX SA3E

Tue May 30, 2017 10:11 am

Rebuilding RIX SA3E Heads
- I don't thinks its accurate to say "Re-Building" the heads. Disassembly, cleaning, and replacing the O-Rings is what's involved. The reed valves are all metal and mainly they're just dirty... In need of cleaning, not replacing. You can see some of the sooty residue here:
Image
- There's a little threaded hole in the center that serves as a holding point for a "PULLER" to facilitate disassembly. I made a puller tool from a machine screw, a nut, and some washers.
Image
- I used this same type of tool to disassemble the 3rd stage head last winter. But the 2nd stage guts were stuck so bad the puller stripped the threads on the screw. I soaked it all overnight in Simple Green and made another puller... This time it worked and pulled the guts out.
Image
- The RIX manual says to use "Joy" dish washing detergent. As mentioned above, I used Simple Green. I also gently "wiped" some of the parts and reed valves across some 1500 grit wet sanding paper on a flat surface... To remove encrusted fouling. I used just a little high pressure (breathing gas) grease on the 024 Viton O-Rings to facilitate easier assembly.
Image
- Test by blowing into the "IN" and "OUT" ports to confirm air only moves one way.
- I re-assembled everything and pumped tanks yesterday... It all still works fine except I am still getting the little outpuffs of air from the intake filter. I put my finger over the hole and it sucks like crazy. But it puffs a little out, too. I think I might ask the folks at RIX about this.
SurfLung
The Freedom and Simplicity of Vintage Equipment and
Vintage Diving Technique are Why I Got Back Into Diving.

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Re: RIX SA3E

Tue May 30, 2017 11:10 am

Eben, try this test on the intake situation. Briefly put a business card over the opening of the intake filter ( if it has a distinct inlet and not just bringing air in around the whole perimeter). While it is running the card should stay in place. If it does, I would suggest that you have no problem. Let me know.

BTW, if your inlet is on a hose away from the actual compressor intake it is common to have the feel of alternating air flow. You would need to take the above test with the inlet filter mounted at the head.
The older I get the better I was.

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SurfLung
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Re: RIX SA3E

Tue Jun 06, 2017 12:43 pm

The Business Card Test...

- After rebuilding the RIX SA3E heads, I could feel puffs of air coming out of the intake filter. I asked RIX about it and they said some small amounts of that are normal. Antique Diver Bill has a test to see how much is normal and acceptable by seeing if the intake will suck and hold a business card... If its back flowing too much, it will blow the card away.
- Voile... It's sucking the card solid!

P.S. Eric Zensius of RIX sent me the following email: "Glad to hear your SA-3E is running and serving you well.
The slight puffing you mention is normal due to the large 1st stage piston pulling and pushing ambient suction pressure. You might remove the filter during operation and see if you have any change you might possibly be restricting suction. Compare the before and after.
SurfLung
The Freedom and Simplicity of Vintage Equipment and
Vintage Diving Technique are Why I Got Back Into Diving.

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