Swapping the JJ-Regs Out

divingtactics · July 30th, 2012, 02:00 AM

If I swap the standard regs out for MK25's and drop the IP on the oxygen side to 7.0 - 7.5 bar what is the issue with the solenoid as I go deeper?

bazSXD · July 30th, 2012, 03:32 AM

Simple question ,,,,,, why in Gods name would you bother ???

regards Baz

PS .... please don't say GUE !

divingtactics · July 30th, 2012, 05:42 AM

Hehehe Baz,

No, that is not the reason. I'm thinking of going to TEK3's due to them having 3 LP ports but then I realised that I have about eight of these MK25's kicking around that I'm not really using, so if I could use them, the hose routing would be a lot better than the current regs on the unit. I am valves up with twin 7 litre cylinders. From memory there was an issue using a balanced or depth compensated regulator, just wanted someone to clarify this.

***nickb*** · July 30th, 2012, 08:22 AM

Dave T advised against using piston regs on the O2 side

ccrdave · July 30th, 2012, 09:11 AM

on the o2 side dry sealed regs are not so good as the interstage pressure creeps up a little as you go deeper. The interstage pressure on the o2 side is set at about 7bar as that is the pressure/voltage relationship that will ensure battery warnings are displayed before the voltage is too low to open the solenoid

piston regs are not recommended as they are much harder to set and adjust IP

On the dil side any good first stage will work, dont forget to add a OPV and again I wouldnt reccomend dry sealed ones as the bov (if you have one) is not very capable of dealing with rising IP

HTH

divingtactics · July 30th, 2012, 09:50 AM

Ok, Dave, so if I can set the IP of a MK25 to 7 bar then it would be okay to use.

ccrdave · July 30th, 2012, 10:24 AM

Quote: (Originally Posted by divingtactics)

Ok, Dave, so if I can set the IP of a MK25 to 7 bar then it would be okay to use.

I dont see why not, as long as you can get the IP down that far. I am not familliar with the mk 25 but if its a piston first stage the IP is either is factory set or its adjusted with shims.
If you do it I would keep checking the IP to make sure it doesnt creep and dont forget the OPV, and dont be tempted to run a higher IP cos you cant get the mk25 where it should be.

Actually the very first JJ's had scubapro first stages but they were diafram ones

divingtactics · July 30th, 2012, 10:33 AM

Ok great thanks Dave,

The MK25 has a screw adjuster for the IP, so I'll see if I can get one down far enough, then O2 clean it, rekit it and then reset it again, do a couple of dives and check and reset the IP again. They are fairly stable once the seat beds in.

If I can't get it to 7 bar I will just buy some TEK3's.

***nickb*** · July 30th, 2012, 10:40 AM

Quote: (Originally Posted by divingtactics)

Ok great thanks Dave,

The MK25 has a screw adjuster for the IP, so I'll see if I can get one down far enough, then O2 clean it, rekit it and then reset it again, do a couple of dives and check and reset the IP again. They are fairly stable once the seat beds in.

If I can't get it to 7 bar I will just buy some TEK3's.

The adjustment on a Mk25 is about + or - 1 bar. I doubt you'll get it down to 7 with that alone. You'll need to remove shims and even then it might not be possible unless you can get a weaker spring.

ccrdave · July 30th, 2012, 11:37 AM

Quote: (Originally Posted by nickb)

The adjustment on a Mk25 is about + or - 1 bar. I doubt you'll get it down to 7 with that alone. You'll need to remove shims and even then it might not be possible unless you can get a weaker spring.

And if you have to do that I wouldnt bother, the apex regs are very stable and reliable. with cylinders in the correct position and a little bit of thought you can end up with one medium and one high pressure hose from each reg, fit button gauges and a manifold fitting on the o2 side and you just have one hose from each reg.
But I guess if you want to deinvert the cylinders hose routing is a little more difficult.
I can not understand why people deinvert anyway, I can get at my valves a darn sight quicker when they are where there meant to be!! and the regs are more protected down by my fat arse

July 30th, 2012, 02:00 AM	#1 (permalink)
divingtactics Serious Swagelok Addict Join Date: Mar 2012 Location: Melbourne Australia Posts: 156 Thanks: 17 Thanked 16 Times in 15 Posts	Swapping the JJ-Regs Out If I swap the standard regs out for MK25's and drop the IP on the oxygen side to 7.0 - 7.5 bar what is the issue with the solenoid as I go deeper?
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July 30th, 2012, 03:32 AM	#2 (permalink)
bazSXD New Member Join Date: Mar 2012 Location: Sydney Oz Posts: 59 Thanks: 1 Thanked 4 Times in 3 Posts	Simple question ,,,,,, why in Gods name would you bother ??? regards Baz PS .... please don't say GUE !
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July 30th, 2012, 05:42 AM	#3 (permalink)
divingtactics Serious Swagelok Addict Join Date: Mar 2012 Location: Melbourne Australia Posts: 156 Thanks: 17 Thanked 16 Times in 15 Posts	Hehehe Baz, No, that is not the reason. I'm thinking of going to TEK3's due to them having 3 LP ports but then I realised that I have about eight of these MK25's kicking around that I'm not really using, so if I could use them, the hose routing would be a lot better than the current regs on the unit. I am valves up with twin 7 litre cylinders. From memory there was an issue using a balanced or depth compensated regulator, just wanted someone to clarify this.
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July 30th, 2012, 08:22 AM	#4 (permalink)
*nickb* The JJ Kid Join Date: Mar 2012 Location: Cardiff, UK Posts: 516 Thanks: 78 Thanked 90 Times in 62 Posts	Dave T advised against using piston regs on the O2 side
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July 30th, 2012, 09:11 AM	#5 (permalink)
ccrdave New Member Join Date: Mar 2012 Location: forest of Dean Posts: 206 Thanks: 0 Thanked 6 Times in 5 Posts	on the o2 side dry sealed regs are not so good as the interstage pressure creeps up a little as you go deeper. The interstage pressure on the o2 side is set at about 7bar as that is the pressure/voltage relationship that will ensure battery warnings are displayed before the voltage is too low to open the solenoid piston regs are not recommended as they are much harder to set and adjust IP On the dil side any good first stage will work, dont forget to add a OPV and again I wouldnt reccomend dry sealed ones as the bov (if you have one) is not very capable of dealing with rising IP HTH
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July 30th, 2012, 09:50 AM	#6 (permalink)
divingtactics Serious Swagelok Addict Join Date: Mar 2012 Location: Melbourne Australia Posts: 156 Thanks: 17 Thanked 16 Times in 15 Posts	Ok, Dave, so if I can set the IP of a MK25 to 7 bar then it would be okay to use.
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July 30th, 2012, 10:24 AM	#7 (permalink)
ccrdave New Member Join Date: Mar 2012 Location: forest of Dean Posts: 206 Thanks: 0 Thanked 6 Times in 5 Posts	Quote: (Originally Posted by divingtactics) Ok, Dave, so if I can set the IP of a MK25 to 7 bar then it would be okay to use. I dont see why not, as long as you can get the IP down that far. I am not familliar with the mk 25 but if its a piston first stage the IP is either is factory set or its adjusted with shims. If you do it I would keep checking the IP to make sure it doesnt creep and dont forget the OPV, and dont be tempted to run a higher IP cos you cant get the mk25 where it should be. Actually the very first JJ's had scubapro first stages but they were diafram ones
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July 30th, 2012, 10:33 AM	#8 (permalink)
divingtactics Serious Swagelok Addict Join Date: Mar 2012 Location: Melbourne Australia Posts: 156 Thanks: 17 Thanked 16 Times in 15 Posts	Ok great thanks Dave, The MK25 has a screw adjuster for the IP, so I'll see if I can get one down far enough, then O2 clean it, rekit it and then reset it again, do a couple of dives and check and reset the IP again. They are fairly stable once the seat beds in. If I can't get it to 7 bar I will just buy some TEK3's. Last edited by divingtactics; July 30th, 2012 at 10:36 AM.
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July 30th, 2012, 10:40 AM	#9 (permalink)
*nickb* The JJ Kid Join Date: Mar 2012 Location: Cardiff, UK Posts: 516 Thanks: 78 Thanked 90 Times in 62 Posts	Quote: (Originally Posted by divingtactics) Ok great thanks Dave, The MK25 has a screw adjuster for the IP, so I'll see if I can get one down far enough, then O2 clean it, rekit it and then reset it again, do a couple of dives and check and reset the IP again. They are fairly stable once the seat beds in. If I can't get it to 7 bar I will just buy some TEK3's. The adjustment on a Mk25 is about + or - 1 bar. I doubt you'll get it down to 7 with that alone. You'll need to remove shims and even then it might not be possible unless you can get a weaker spring.
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July 30th, 2012, 11:37 AM	#10 (permalink)
ccrdave New Member Join Date: Mar 2012 Location: forest of Dean Posts: 206 Thanks: 0 Thanked 6 Times in 5 Posts	Quote: (Originally Posted by nickb) The adjustment on a Mk25 is about + or - 1 bar. I doubt you'll get it down to 7 with that alone. You'll need to remove shims and even then it might not be possible unless you can get a weaker spring. And if you have to do that I wouldnt bother, the apex regs are very stable and reliable. with cylinders in the correct position and a little bit of thought you can end up with one medium and one high pressure hose from each reg, fit button gauges and a manifold fitting on the o2 side and you just have one hose from each reg. But I guess if you want to deinvert the cylinders hose routing is a little more difficult. I can not understand why people deinvert anyway, I can get at my valves a darn sight quicker when they are where there meant to be!! and the regs are more protected down by my fat arse
(Online)