Cylinder for Dolphin

trey · 16th December 2005, 21:57

Quote: (Originally Posted by Scuba_Vixen)

Whoaaaa,
When you say converted to a "standard first stage", ... are you refering to the the threading as in DIN adapter on the Drager reg, or did you switch away from the Drager reg to something else ?

Using something other than the Drager reg is not a very sound idea, as it'll screw up everything about the flowrates and dosage.

The Drager reg is not depth compensated, you get a constant mass flow regardless of depth. Its IP is also about 165#, that's what all the flow orifice size calibrations are based around.

Setting it up to use a standard DIN tank valve makes sense, changing to a different reg does not.

Darlene

Someone correct me if I'm wrong, but the standard Draeger reg is depth compensated...and you are correct, the IP is at about 165psi (modification being made). Now, the mCCR KISS set-up that you dive does have a reg that is not depth compensated...the O2 reg. The Dil reg is depth compensated on your unit. The difference from a standard reg, from what I understand, is that the stock Draeger reg has a feature that creeps up the IP if the orifice is not flowing at it's advertised rate...that is something I'll be missing...and yes, that could be bad. But diligent monitoring of PPO2 should allow you plenty of time to bail to OC in the event of an orifice failure. Comments?

***caveseeker7*** · 17th December 2005, 00:29

Somebody correct me I'm wrong (that's rethorical, don't you dare

) but the interstage pressure for a stock Dolphin is 16.5 bar/240 psi.

Scuba_Vixen · 17th December 2005, 03:11

Quote: (Originally Posted by caveseeker7)

Somebody correct me I'm wrong (that's rethorical, don't you dare

) but the interstage pressure for a stock Dolphin is 16.5 bar/240 psi.

Akkkkk, You're absolutely correct!

Somehow I turned 16.5 bar into 165#.

Trey,
The Drager reg is NOT depth compensated.

These guys will chime in if they've seen it done, but I've not heard of anyone replacing the Drager reg on the Dolphin when it's used in it's normal SCR mode.

Darlene

Scuba_Vixen · 17th December 2005, 03:32

Quote: (Originally Posted by trey)

Someone correct me if I'm wrong, but the standard Draeger reg is depth compensated...and you are correct, the IP is at about 165psi (modification being made). Now, the mCCR KISS set-up that you dive does have a reg that is not depth compensated...the O2 reg. The Dil reg is depth compensated on your unit. The difference from a standard reg, from what I understand, is that the stock Draeger reg has a feature that creeps up the IP if the orifice is not flowing at it's advertised rate...that is something I'll be missing...and yes, that could be bad. But diligent monitoring of PPO2 should allow you plenty of time to bail to OC in the event of an orifice failure. Comments?

Trey,
Where did you hear this from, ..... It doesn't make any sense.

There's 5 possible orifices that could be in use. How can the reg know which one it is, to know if the flowrate is low so it could creep the IP.

When you do your setup, you use the specified flowmeters and the right orifice for that mix, to determine if the flowrate is correct. If there's a partial clog of the orifice pair, then you'll just have low flowrate. The IP isn't going to try to compensate. The reg can't tell if it's a partial clog of the 32% orifice, or a perfectly normal flow on the 40% orifice.

Stay with the original Drager reg for SCR use.

Darlene

denzel · 17th December 2005, 17:52

Hi Darlene,

All good, and you're more then correct, definatly stay with the dolphin 1st stage for scr, but IIRC someone tried to use the dolphin 1st stage for CCR and found out that if you close the flow off, i mean tank open, but nowhere for the air to go, that the IP will creep up.....

denz.

trey · 18th December 2005, 23:01

Wow...so in that case I can't use a standard reg without blocking it and raising the IP substantially. I was told that a standard reg WOULD work and that the IP only needed to be increased slightly (about 10PSI). Two hundred and something PSI is not a slight increase over the standard 155PSI range. That really sucks, cuz now I've already ordered everything to convert it to standard thread reg...guess I'll save it for CCR later! So, does anyone have a standard stock DOT 27cu ft tank for sale cheap? Cuz that's the only thing my short ass stock hoses will reach...anyone had any experience with standard LP hose adapters on the stock regs? Or has anyone modified a reg for use on a SCR Dolphin?

Thanks, Trey

Scuba_Vixen · 19th December 2005, 00:02

Quote: (Originally Posted by trey)

Wow...so in that case I can't use a standard reg without blocking it and raising the IP substantially. I was told that a standard reg WOULD work and that the IP only needed to be increased slightly (about 10PSI). Two hundred and something PSI is not a slight increase over the standard 155PSI range. That really sucks, cuz now I've already ordered everything to convert it to standard thread reg...guess I'll save it for CCR later! So, does anyone have a standard stock DOT 27cu ft tank for sale cheap? Cuz that's the only thing my short ass stock hoses will reach...anyone had any experience with standard LP hose adapters on the stock regs? Or has anyone modified a reg for use on a SCR Dolphin?

Thanks, Trey

Be carefull what hoses you use with the stock Drager reg.

A lot of LP hoses are only 250# rated. The good ones are 420# rated, 6mm ID (you can get them over a 1/4" hose barb with enough effort) ..... Scuba Pro seems to be the only ones I've found here handy that are the higher rated ones. Some who've done conversions and gotten hose from AP Valves have the 420# hose as well.

Considering the look and feel of each type of hose when I've cut them for some reason, I'd not feel comfy with using anything but the 420# hose on a 240psi drager reg.

If I were to think out loud of how to manage if I didn't have a drager reg, and did have standard reg hoses ........

I'd be thinking something like a blocked DS4 with the IP set as high as possible but where it still stays stable.

I'd think maybe a SP G250 spring in the ADV,

I'd be thinking Dwyer flowmeters mma23 and mma24 to see where the hell I ended up at.

Geeeez, What a Pandora's Box, .... Find a Drager reg.

Darlene

Bubble Boy · 19th December 2005, 04:53

Darlene,
You are correct the drager first stage is NOT depth compensated and runs at an IP of 220-240psi. They are agricultural and bullet proof.

The only 1st stage I've heard of other than a std Drager one which can be used is a Scubapro Mk20/25 as these can be shimmed up to an appropriate Ip and run that way for a long time without blowing seats. this may have changed with new first stages but around 18mths ago this was the only other option for a Drager SCR 1st stage.

Obviously if you are using it for CCR conversion and not delivering through a sonic orifice then any old sealed first stage will do.

trey · 19th December 2005, 14:07

Quote: (Originally Posted by Bubble Boy)

Darlene,
You are correct the drager first stage is NOT depth compensated and runs at an IP of 220-240psi. They are agricultural and bullet proof.

The only 1st stage I've heard of other than a std Drager one which can be used is a Scubapro Mk20/25 as these can be shimmed up to an appropriate Ip and run that way for a long time without blowing seats. this may have changed with new first stages but around 18mths ago this was the only other option for a Drager SCR 1st stage.

Obviously if you are using it for CCR conversion and not delivering through a sonic orifice then any old sealed first stage will do.

So if I used the Scuba Pro reg, does someone make a blocker plug for it?

Thanks, T

jswensva · 19th December 2005, 14:12

I used a Genesis (Asahi) 80 cu ft. high pressure steel. Shorter than a 40 or 45. And, since I've sold my Dolphin, I'll be glad to sell this to you

16th December 2005, 21:57	#11 (permalink)
trey Total NOOB Current Rebreather/s: Dolphin Other Rebreather/s: Dolphin Join Date: Aug 2005 Location: Austin, TX Posts: 108	Re: Cylinder for Dolphin Quote: (Originally Posted by Scuba_Vixen) Whoaaaa, When you say converted to a "standard first stage", ... are you refering to the the threading as in DIN adapter on the Drager reg, or did you switch away from the Drager reg to something else ? Using something other than the Drager reg is not a very sound idea, as it'll screw up everything about the flowrates and dosage. The Drager reg is not depth compensated, you get a constant mass flow regardless of depth. Its IP is also about 165#, that's what all the flow orifice size calibrations are based around. Setting it up to use a standard DIN tank valve makes sense, changing to a different reg does not. Darlene Someone correct me if I'm wrong, but the standard Draeger reg is depth compensated...and you are correct, the IP is at about 165psi (modification being made). Now, the mCCR KISS set-up that you dive does have a reg that is not depth compensated...the O2 reg. The Dil reg is depth compensated on your unit. The difference from a standard reg, from what I understand, is that the stock Draeger reg has a feature that creeps up the IP if the orifice is not flowing at it's advertised rate...that is something I'll be missing...and yes, that could be bad. But diligent monitoring of PPO2 should allow you plenty of time to bail to OC in the event of an orifice failure. Comments?
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17th December 2005, 00:29	#12 (permalink)
*caveseeker7* Who loves ya, baby Current Rebreather/s: Sport Kiss Other Rebreather/s: Prism Topaz Join Date: Jan 2005 Location: Too far from Neverland Posts: 5,496	Re: Cylinder for Dolphin Somebody correct me I'm wrong (that's rethorical, don't you dare ) but the interstage pressure for a stock Dolphin is 16.5 bar/240 psi. __________________ Cheers Stefan "Political Correctness is a doctrine, fostered by a delusional, illogical minority, and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a turd by the clean end.!"
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17th December 2005, 03:11	#13 (permalink)
Scuba_Vixen e/mCCR Dolphin Pilot Current Rebreather/s: Other CCR Home Build Other Rebreather/s: Other CCR Home Build Join Date: May 2005 Location: St. Croix USVI Posts: 557	Re: Cylinder for Dolphin Quote: (Originally Posted by caveseeker7) Somebody correct me I'm wrong (that's rethorical, don't you dare ) but the interstage pressure for a stock Dolphin is 16.5 bar/240 psi. Akkkkk, You're absolutely correct! Somehow I turned 16.5 bar into 165#. Trey, The Drager reg is NOT depth compensated. These guys will chime in if they've seen it done, but I've not heard of anyone replacing the Drager reg on the Dolphin when it's used in it's normal SCR mode. Darlene
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17th December 2005, 03:32	#14 (permalink)
Scuba_Vixen e/mCCR Dolphin Pilot Current Rebreather/s: Other CCR Home Build Other Rebreather/s: Other CCR Home Build Join Date: May 2005 Location: St. Croix USVI Posts: 557	Re: Cylinder for Dolphin Quote: (Originally Posted by trey) Someone correct me if I'm wrong, but the standard Draeger reg is depth compensated...and you are correct, the IP is at about 165psi (modification being made). Now, the mCCR KISS set-up that you dive does have a reg that is not depth compensated...the O2 reg. The Dil reg is depth compensated on your unit. The difference from a standard reg, from what I understand, is that the stock Draeger reg has a feature that creeps up the IP if the orifice is not flowing at it's advertised rate...that is something I'll be missing...and yes, that could be bad. But diligent monitoring of PPO2 should allow you plenty of time to bail to OC in the event of an orifice failure. Comments? Trey, Where did you hear this from, ..... It doesn't make any sense. There's 5 possible orifices that could be in use. How can the reg know which one it is, to know if the flowrate is low so it could creep the IP. When you do your setup, you use the specified flowmeters and the right orifice for that mix, to determine if the flowrate is correct. If there's a partial clog of the orifice pair, then you'll just have low flowrate. The IP isn't going to try to compensate. The reg can't tell if it's a partial clog of the 32% orifice, or a perfectly normal flow on the 40% orifice. Stay with the original Drager reg for SCR use. Darlene
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17th December 2005, 17:52	#15 (permalink)
denzel Holiday diver Current Rebreather/s: Inspiration Classic Other Rebreather/s: Not Bought Yet Join Date: Aug 2005 Location: Perth! Posts: 358	Re: Cylinder for Dolphin Hi Darlene, All good, and you're more then correct, definatly stay with the dolphin 1st stage for scr, but IIRC someone tried to use the dolphin 1st stage for CCR and found out that if you close the flow off, i mean tank open, but nowhere for the air to go, that the IP will creep up..... denz. __________________ My deepest so far, 558.50 mtr, my rig a LF90D...
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18th December 2005, 23:01	#16 (permalink)
trey Total NOOB Current Rebreather/s: Dolphin Other Rebreather/s: Dolphin Join Date: Aug 2005 Location: Austin, TX Posts: 108	Re: Cylinder for Dolphin Wow...so in that case I can't use a standard reg without blocking it and raising the IP substantially. I was told that a standard reg WOULD work and that the IP only needed to be increased slightly (about 10PSI). Two hundred and something PSI is not a slight increase over the standard 155PSI range. That really sucks, cuz now I've already ordered everything to convert it to standard thread reg...guess I'll save it for CCR later! So, does anyone have a standard stock DOT 27cu ft tank for sale cheap? Cuz that's the only thing my short ass stock hoses will reach...anyone had any experience with standard LP hose adapters on the stock regs? Or has anyone modified a reg for use on a SCR Dolphin? Thanks, Trey
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19th December 2005, 00:02	#17 (permalink)
Scuba_Vixen e/mCCR Dolphin Pilot Current Rebreather/s: Other CCR Home Build Other Rebreather/s: Other CCR Home Build Join Date: May 2005 Location: St. Croix USVI Posts: 557	Re: Cylinder for Dolphin Quote: (Originally Posted by trey) Wow...so in that case I can't use a standard reg without blocking it and raising the IP substantially. I was told that a standard reg WOULD work and that the IP only needed to be increased slightly (about 10PSI). Two hundred and something PSI is not a slight increase over the standard 155PSI range. That really sucks, cuz now I've already ordered everything to convert it to standard thread reg...guess I'll save it for CCR later! So, does anyone have a standard stock DOT 27cu ft tank for sale cheap? Cuz that's the only thing my short ass stock hoses will reach...anyone had any experience with standard LP hose adapters on the stock regs? Or has anyone modified a reg for use on a SCR Dolphin? Thanks, Trey Be carefull what hoses you use with the stock Drager reg. A lot of LP hoses are only 250# rated. The good ones are 420# rated, 6mm ID (you can get them over a 1/4" hose barb with enough effort) ..... Scuba Pro seems to be the only ones I've found here handy that are the higher rated ones. Some who've done conversions and gotten hose from AP Valves have the 420# hose as well. Considering the look and feel of each type of hose when I've cut them for some reason, I'd not feel comfy with using anything but the 420# hose on a 240psi drager reg. If I were to think out loud of how to manage if I didn't have a drager reg, and did have standard reg hoses ........ I'd be thinking something like a blocked DS4 with the IP set as high as possible but where it still stays stable. I'd think maybe a SP G250 spring in the ADV, I'd be thinking Dwyer flowmeters mma23 and mma24 to see where the hell I ended up at. Geeeez, What a Pandora's Box, .... Find a Drager reg. Darlene Last edited by Scuba_Vixen : 19th December 2005 at 00:07.
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19th December 2005, 04:53	#18 (permalink)
Bubble Boy PRISMs are kewl Current Rebreather/s: Prism Topaz MK 15.X Other CCR Dolphin Ray Other Rebreather/s: Other CCR Dolphin Ray Join Date: Mar 2005 Location: Sydney Australia Posts: 132	Re: Cylinder for Dolphin Darlene, You are correct the drager first stage is NOT depth compensated and runs at an IP of 220-240psi. They are agricultural and bullet proof. The only 1st stage I've heard of other than a std Drager one which can be used is a Scubapro Mk20/25 as these can be shimmed up to an appropriate Ip and run that way for a long time without blowing seats. this may have changed with new first stages but around 18mths ago this was the only other option for a Drager SCR 1st stage. Obviously if you are using it for CCR conversion and not delivering through a sonic orifice then any old sealed first stage will do.
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19th December 2005, 14:07	#19 (permalink)
trey Total NOOB Current Rebreather/s: Dolphin Other Rebreather/s: Dolphin Join Date: Aug 2005 Location: Austin, TX Posts: 108	Re: Cylinder for Dolphin Quote: (Originally Posted by Bubble Boy) Darlene, You are correct the drager first stage is NOT depth compensated and runs at an IP of 220-240psi. They are agricultural and bullet proof. The only 1st stage I've heard of other than a std Drager one which can be used is a Scubapro Mk20/25 as these can be shimmed up to an appropriate Ip and run that way for a long time without blowing seats. this may have changed with new first stages but around 18mths ago this was the only other option for a Drager SCR 1st stage. Obviously if you are using it for CCR conversion and not delivering through a sonic orifice then any old sealed first stage will do. So if I used the Scuba Pro reg, does someone make a blocker plug for it? Thanks, T
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19th December 2005, 14:12	#20 (permalink)
jswensva Future Meg Diver Current Rebreather/s: Dolphin Other Rebreather/s: Dolphin Join Date: Feb 2005 Location: Richmond, VA Posts: 28	Re: Cylinder for Dolphin I used a Genesis (Asahi) 80 cu ft. high pressure steel. Shorter than a 40 or 45. And, since I've sold my Dolphin, I'll be glad to sell this to you
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