SA rix compressor and nitrox continuous blending

**jmurba** · 2nd April 2007, 13:53

Quote: (Originally Posted by gkndivebum)

I continuous blend using my SA-6. As stated, heat is a problem, particularly here in
the middle of the Pacific. I try to blend when it's "cool" out - early morning, evening.
I have a fan that I use to force air across the compressor.

It works Ok, but I have to service the 3rd stage head every 50-70 hours. I've taken
to using teflon o-rings in the 3rd stage head (they're 018s if you care) and seem to have
better life out of them, at the expense of being a pain in the backside to install.

I haven't found a good solution to the o-ring on the head plug - it's an 012, but the
teflon 012s don't have enough stretch to fit over the threads on the plug and
retain their integrity. So I'm still using viton there, but they don't last worth beans.

YMMV, but probably not by much.

Hi,
thanks for details
what is the noise level of a rix compared to a bauer for example ?
regards
jean mi

iain-hsm · 2nd April 2007, 15:09

Quote: (Originally Posted by gkndivebum)

I haven't found a good solution to the o-ring on the head plug - it's an 012, but the teflon 012s don't have enough stretch to fit over the threads on the plug and retain their integrity. So I'm still using viton there, but they don't last worth beans.
YMMV, but probably not by much.

Your using the wrong size o-ring. 012 is NOT the correct part for the 3rd plug. You may want to check your 2nd stage inter stage pressure 30-35 bar at 200 bar discharge pressure is where you should be anything less is staving that 3rd stage of inlet pressure and overheating the o-rings. Use soapy water froth and check all the pipe work for leaks. I guess you could also have a leak in the cooling coils or fittings starving the 3rd stage of pressure.

If you still have low 2nd stage pressure check the reed valves are correctly seated on the 2nd valve, with the head off and in your hand, blow and suck through the inlet/outlet connections, the valves should seat and seal, if they leak, change the 0-rings out or the valve reeds. Take 20 minutes max.

iain-hsm · 2nd April 2007, 15:20

Quote: (Originally Posted by jmurba)

Hi,
thanks for details
what is the noise level of a rix compared to a bauer for example ?
regards jean mi

Jean
Depends on the application, the gas, discharge pressure and climate, four six and eight bladed fans are availible although the 8 blade is what is supplied mostly. Of this size two pitch angles, a 30 degee (quite) and a zero degree (noisy but cooler) pitch angle, assuming a 1500 rpm at 1 meter this equates to a 85dba

iain-hsm · 2nd April 2007, 15:28

Quote: (Originally Posted by gkndivebum)

I continuous blend using my SA-6. As stated, heat is a problem, particularly here in
the middle of the Pacific. I try to blend when it's "cool" out - early morning, evening.
I have a fan that I use to force air across the compressor.

It works Ok, but I have to service the 3rd stage head every 50-70 hours. I've taken
to using teflon o-rings in the 3rd stage head (they're 018s if you care) and seem to have
better life out of them, at the expense of being a pain in the backside to install.

I haven't found a good solution to the o-ring on the head plug - it's an 012, but the
teflon 012s don't have enough stretch to fit over the threads on the plug and
retain their integrity. So I'm still using viton there, but they don't last worth beans. YMMV, but probably not by much.

Another thing you could look into is the quality of your orings in the first place. When you use an oring for critical use never buy cheap hydraulic orings as there are mostly out of gauge and out of shelf life.
Sold as Viton most of this cheap crap is from China as most hydraulic shops have a shelf life in excees of 10 years, you get the picture.

If you were to use the correct Viton compound, an Aircraft grade oring size and with a cure date and compond number, you will be surprised on how much more miles you will get from these little rings.
Aircraft grade, compound, cure date,

**jmurba** · 2nd April 2007, 17:04

Quote: (Originally Posted by iain-hsm)

Jean
Depends on the application, the gas, discharge pressure and climate, four six and eight bladed fans are availible although the 8 blade is what is supplied mostly. Of this size two pitch angles, a 30 degee (quite) and a zero degree (noisy but cooler) pitch angle, assuming a 1500 rpm at 1 meter this equates to a 85dba

85 db at one meter... is it the normal compressor noise ?

***jradomski*** · 2nd April 2007, 17:32

Quote: (Originally Posted by jmurba)

85 db at one meter... is it the normal compressor noise ?

look at this page for a comparison of "normal" sounds

ESPN SportsFigures

**jmurba** · 2nd April 2007, 18:50

Quote: (Originally Posted by jradomski)

look at this page for a comparison of "normal" sounds

ESPN SportsFigures

Thanks for the ink , very interresting, it makes me unsderstant things,
It was very funny when I was trying different buzzers for my oxymeter gauge, there was a graph showing the db against voltage supply, at five volt it gave 70 db, and at 12v 85 Db, I really thought that the difference btw 70 and 85 was negligeable....as I could not hear anything underwater I put 15v in the ****king buzzer, now when my high alarm rings my 2 buddies start staring their own gauge (((-:
now I understand the scale....

regards

jean mi

**jmurba** · 2nd April 2007, 19:40

Quote: (Originally Posted by jmurba)

85 db at one meter... is it the normal compressor noise ?

the bauer is given for 87db on their site, the colptri 81 db

iain-hsm · 2nd April 2007, 20:27

I just love that list Joe but I cant work out in what country would a Rocket Launch be classed as a "normal sound" lol We do have some small missile compressors used for filling the sidewinder missile, if you are interested!!
For the rest of us a scuba compressor is enough.

***jradomski*** · 3rd April 2007, 04:56

Quote: (Originally Posted by iain-hsm)

I just love that list Joe but I cant work out in what country would a Rocket Launch be classed as a "normal sound" lol We do have some small missile compressors used for filling the sidewinder missile, if you are interested!!
For the rest of us a scuba compressor is enough.

Hey if you live in florida by the space center you might call it a "normal" sound.. but I wouldnt want to be within 1 meter!

2nd April 2007, 13:53	#11 (permalink)
jmurba wet bear Current Rebreather/s: Home Build Other Rebreather/s: Home Build Join Date: May 2006 Location: cannes france Posts: 861	Re: SA rix compressor and nitrox continuous blending Quote: (Originally Posted by gkndivebum) I continuous blend using my SA-6. As stated, heat is a problem, particularly here in the middle of the Pacific. I try to blend when it's "cool" out - early morning, evening. I have a fan that I use to force air across the compressor. It works Ok, but I have to service the 3rd stage head every 50-70 hours. I've taken to using teflon o-rings in the 3rd stage head (they're 018s if you care) and seem to have better life out of them, at the expense of being a pain in the backside to install. I haven't found a good solution to the o-ring on the head plug - it's an 012, but the teflon 012s don't have enough stretch to fit over the threads on the plug and retain their integrity. So I'm still using viton there, but they don't last worth beans. YMMV, but probably not by much. Hi, thanks for details what is the noise level of a rix compared to a bauer for example ? regards jean mi __________________ when will I be able to think about something else then spending hours underwater, when will I be normal ? http://web.mac.com/jmurba/Site_2/home.html http://web.mac.com/jmurba/Site_3/home.html
(Offline)

2nd April 2007, 15:09	#12 (permalink)
iain-hsm Custom Title Allowed! Current Rebreather/s: MK 15.X Other CCR Other SCR Other Rebreather/s: Other CCR Other SCR Join Date: Mar 2005 Location: Loughborough England uk Posts: 347	Re: SA rix compressor and nitrox continuous blending Quote: (Originally Posted by gkndivebum) I haven't found a good solution to the o-ring on the head plug - it's an 012, but the teflon 012s don't have enough stretch to fit over the threads on the plug and retain their integrity. So I'm still using viton there, but they don't last worth beans. YMMV, but probably not by much. Your using the wrong size o-ring. 012 is NOT the correct part for the 3rd plug. You may want to check your 2nd stage inter stage pressure 30-35 bar at 200 bar discharge pressure is where you should be anything less is staving that 3rd stage of inlet pressure and overheating the o-rings. Use soapy water froth and check all the pipe work for leaks. I guess you could also have a leak in the cooling coils or fittings starving the 3rd stage of pressure. If you still have low 2nd stage pressure check the reed valves are correctly seated on the 2nd valve, with the head off and in your hand, blow and suck through the inlet/outlet connections, the valves should seat and seal, if they leak, change the 0-rings out or the valve reeds. Take 20 minutes max.
(Offline)

2nd April 2007, 15:20	#13 (permalink)
iain-hsm Custom Title Allowed! Current Rebreather/s: MK 15.X Other CCR Other SCR Other Rebreather/s: Other CCR Other SCR Join Date: Mar 2005 Location: Loughborough England uk Posts: 347	Re: SA rix compressor and nitrox continuous blending Quote: (Originally Posted by jmurba) Hi, thanks for details what is the noise level of a rix compared to a bauer for example ? regards jean mi Jean Depends on the application, the gas, discharge pressure and climate, four six and eight bladed fans are availible although the 8 blade is what is supplied mostly. Of this size two pitch angles, a 30 degee (quite) and a zero degree (noisy but cooler) pitch angle, assuming a 1500 rpm at 1 meter this equates to a 85dba
(Offline)

2nd April 2007, 15:28	#14 (permalink)
iain-hsm Custom Title Allowed! Current Rebreather/s: MK 15.X Other CCR Other SCR Other Rebreather/s: Other CCR Other SCR Join Date: Mar 2005 Location: Loughborough England uk Posts: 347	Re: SA rix compressor and nitrox continuous blending Quote: (Originally Posted by gkndivebum) I continuous blend using my SA-6. As stated, heat is a problem, particularly here in the middle of the Pacific. I try to blend when it's "cool" out - early morning, evening. I have a fan that I use to force air across the compressor. It works Ok, but I have to service the 3rd stage head every 50-70 hours. I've taken to using teflon o-rings in the 3rd stage head (they're 018s if you care) and seem to have better life out of them, at the expense of being a pain in the backside to install. I haven't found a good solution to the o-ring on the head plug - it's an 012, but the teflon 012s don't have enough stretch to fit over the threads on the plug and retain their integrity. So I'm still using viton there, but they don't last worth beans. YMMV, but probably not by much. Another thing you could look into is the quality of your orings in the first place. When you use an oring for critical use never buy cheap hydraulic orings as there are mostly out of gauge and out of shelf life. Sold as Viton most of this cheap crap is from China as most hydraulic shops have a shelf life in excees of 10 years, you get the picture. If you were to use the correct Viton compound, an Aircraft grade oring size and with a cure date and compond number, you will be surprised on how much more miles you will get from these little rings. Aircraft grade, compound, cure date,
(Offline)

2nd April 2007, 17:04	#15 (permalink)
jmurba wet bear Current Rebreather/s: Home Build Other Rebreather/s: Home Build Join Date: May 2006 Location: cannes france Posts: 861	Re: SA rix compressor and nitrox continuous blending Quote: (Originally Posted by iain-hsm) Jean Depends on the application, the gas, discharge pressure and climate, four six and eight bladed fans are availible although the 8 blade is what is supplied mostly. Of this size two pitch angles, a 30 degee (quite) and a zero degree (noisy but cooler) pitch angle, assuming a 1500 rpm at 1 meter this equates to a 85dba 85 db at one meter... is it the normal compressor noise ? __________________ when will I be able to think about something else then spending hours underwater, when will I be normal ? http://web.mac.com/jmurba/Site_2/home.html http://web.mac.com/jmurba/Site_3/home.html
(Offline)

2nd April 2007, 17:32	#16 (permalink)
*jradomski* Moderator Current Rebreather/s: Inspiration Classic Sport Kiss Optima rEvo Other CCR Home Build Other Rebreather/s: Inspiration Vision Evolution Megalodon Classic Kiss rEvo Other CCR Home Build Join Date: Mar 2005 Location: "Da" Bronx Posts: 3,001	Re: SA rix compressor and nitrox continuous blending Quote: (Originally Posted by jmurba) 85 db at one meter... is it the normal compressor noise ? look at this page for a comparison of "normal" sounds ESPN SportsFigures __________________ Joe Radomski CCR Trimix Instructor Trainer ANDI Instructor Trainer Director #10 All posts are personal opinions and DO NOT reflect any affiliated agency unless specifically stated.
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2nd April 2007, 18:50	#17 (permalink)
jmurba wet bear Current Rebreather/s: Home Build Other Rebreather/s: Home Build Join Date: May 2006 Location: cannes france Posts: 861	Re: SA rix compressor and nitrox continuous blending Quote: (Originally Posted by jradomski) look at this page for a comparison of "normal" sounds ESPN SportsFigures Thanks for the ink , very interresting, it makes me unsderstant things, It was very funny when I was trying different buzzers for my oxymeter gauge, there was a graph showing the db against voltage supply, at five volt it gave 70 db, and at 12v 85 Db, I really thought that the difference btw 70 and 85 was negligeable....as I could not hear anything underwater I put 15v in the ****king buzzer, now when my high alarm rings my 2 buddies start staring their own gauge (((-: now I understand the scale.... regards jean mi __________________ when will I be able to think about something else then spending hours underwater, when will I be normal ? http://web.mac.com/jmurba/Site_2/home.html http://web.mac.com/jmurba/Site_3/home.html
(Offline)

2nd April 2007, 19:40	#18 (permalink)
jmurba wet bear Current Rebreather/s: Home Build Other Rebreather/s: Home Build Join Date: May 2006 Location: cannes france Posts: 861	Re: SA rix compressor and nitrox continuous blending Quote: (Originally Posted by jmurba) 85 db at one meter... is it the normal compressor noise ? the bauer is given for 87db on their site, the colptri 81 db __________________ when will I be able to think about something else then spending hours underwater, when will I be normal ? http://web.mac.com/jmurba/Site_2/home.html http://web.mac.com/jmurba/Site_3/home.html
(Offline)

3rd April 2007, 04:56	#20 (permalink)
*jradomski* Moderator Current Rebreather/s: Inspiration Classic Sport Kiss Optima rEvo Other CCR Home Build Other Rebreather/s: Inspiration Vision Evolution Megalodon Classic Kiss rEvo Other CCR Home Build Join Date: Mar 2005 Location: "Da" Bronx Posts: 3,001	Re: SA rix compressor and nitrox continuous blending Quote: (Originally Posted by iain-hsm) I just love that list Joe but I cant work out in what country would a Rocket Launch be classed as a "normal sound" lol We do have some small missile compressors used for filling the sidewinder missile, if you are interested!! For the rest of us a scuba compressor is enough. Hey if you live in florida by the space center you might call it a "normal" sound.. but I wouldnt want to be within 1 meter! __________________ Joe Radomski CCR Trimix Instructor Trainer ANDI Instructor Trainer Director #10 All posts are personal opinions and DO NOT reflect any affiliated agency unless specifically stated.
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