GG Shrimp OC cracking pressure

jdh · 23rd October 2012, 02:14

Anyone have numbers for cracking pressure for new Shrimp BOVs?
I recently bought a used one and couldn't adjust it to crack until over 4" H2O. I haven't had it in the water yet, but it was terrible at the surface.

I took it apart, cleaned/lubed the o-rings and put in a new LP seat and was able to adjust it down to about 3" without freeflowing (adjuster set all the way out). I usually get my Apeks 2nds down around 1.0" doing the same.
The valve seat looks good. The shuttle valve 'arms' have a little wear, but look ok. Same for the lever.
Any suggestions or is this as good as they get?

John

Silentbob · 23rd October 2012, 08:29

I would suspect the "through diaphragm" exhalation exhaust causes a significant increase in cracking pressure.

Looking at my records I have achieved 1.7" cracking pressure at best. The effort at high flows is quite reasonable. Certainly comparable to middle of the road second stages.

How does the balance chamber look? If that's not clean then that can increase effort.

jcook · 23rd October 2012, 11:39

I got mine to 1.6, you also need to make sure the IP on the reg you have it plugged into is properly adjusted.

***jradomski*** · 23rd October 2012, 20:35

Quote: (Originally Posted by jdh)

Anyone have numbers for cracking pressure for new Shrimp BOVs?
I recently bought a used one and couldn't adjust it to crack until over 4" H2O. I haven't had it in the water yet, but it was terrible at the surface.

I took it apart, cleaned/lubed the o-rings and put in a new LP seat and was able to adjust it down to about 3" without freeflowing (adjuster set all the way out). I usually get my Apeks 2nds down around 1.0" doing the same.
The valve seat looks good. The shuttle valve 'arms' have a little wear, but look ok. Same for the lever.
Any suggestions or is this as good as they get?

John

I have mine at 1.5 inches.. What is your IP?

Silentbob · 23rd October 2012, 21:06

Hang on I'm starting to see a trend here, oddly enough its a downsizing trend involving inches..

1.4" anyone?

***jradomski*** · 23rd October 2012, 21:15

Quote: (Originally Posted by Silentbob)

Hang on I'm starting to see a trend here, oddly enough its a downsizing trend involving inches..

1.4" anyone?

who knows... I just adjusted mine until it free flowed then backed off, when I measured it it was 1.5 " and that was good enough for me...

jdh · 24th October 2012, 02:51

Quote: (Originally Posted by jradomski)

I have mine at 1.5 inches.. What is your IP?

IP was 140 at the time. I tried 120-150 this evening and it didn't make much difference.

Took it apart, cleaned everything metal (crown/tube/spring) in the ultrasonic, all squeaky clean. New o-rings. New seat. Balance chamber is good. The lever might be a little bent but seems to function correctly. The little plastic insert in the diaphragm that rests on the lever looks pretty cheap.

The counter balance cylinder doesn't look like any of my regular Apeks ones. It has no nipple at all on the end. Is this some variant I've never seen or a Shrimp modification?

I adjusted it to where it just didn't free-flow and it now starts to crack around 2.5" It doesn't really start flowing decently until closer to 4" though.
It feels like a two-step break. It cracks and barely flows, then at 4", it is actually breathable.

I rebuilt two stage regs this evening (DS4s and TX50/ATX50). They both are reliable around 0.8" at 140psi.

I can swap the crown & shuttle valve from one of my TX50's in but don't have anything to replace the counter balance cylinder or lever.

Any other suggestions?

John

Silentbob · 24th October 2012, 04:16

Maybe get in touch with Jakub. Without being able to see it/play with it diagnosis is tricky.

jdh · 24th October 2012, 21:04

Quote: (Originally Posted by Silentbob)

Maybe get in touch with Jakub. Without being able to see it/play with it diagnosis is tricky.

Tried that... not much help.

Is there a shrimp service manual?

Quote:

There isn’t a manual for the OC portion as it is an Apeks regulator. So same procedures apply.

Should it crack like a normal Apeks reg?
I have 8 or 10 Apeks seconds and I usually can set them just over 1" H2O

Quote:

No, you want it to have more resistance as you do not want it to freeflow, ever.

Silentbob · 24th October 2012, 21:09

Is there much difference between the spring strength in the Golem as opposed to your other regs?

Try swapping out a spring. It's a long shot but the spring in the Golem may be stronger...

23rd October 2012, 02:14	#1 (permalink)
jdh RBW Member rEvo Classic KISS Join Date: Aug 2007 Location: Wilmington, NC Posts: 57	GG Shrimp OC cracking pressure Anyone have numbers for cracking pressure for new Shrimp BOVs? I recently bought a used one and couldn't adjust it to crack until over 4" H2O. I haven't had it in the water yet, but it was terrible at the surface. I took it apart, cleaned/lubed the o-rings and put in a new LP seat and was able to adjust it down to about 3" without freeflowing (adjuster set all the way out). I usually get my Apeks 2nds down around 1.0" doing the same. The valve seat looks good. The shuttle valve 'arms' have a little wear, but look ok. Same for the lever. Any suggestions or is this as good as they get? John
(Online)

23rd October 2012, 08:29	#2 (permalink)
Silentbob Compatabilist Kiss Classic Explorer #424 Join Date: Oct 2009 Location: New Zealand Posts: 253	Re: GG Shrimp OC cracking pressure I would suspect the "through diaphragm" exhalation exhaust causes a significant increase in cracking pressure. Looking at my records I have achieved 1.7" cracking pressure at best. The effort at high flows is quite reasonable. Certainly comparable to middle of the road second stages. How does the balance chamber look? If that's not clean then that can increase effort.
(Offline)

23rd October 2012, 11:39	#3 (permalink)
jcook Doing What Works Meg, Soon a Mega Meg... Hammerhead, Ouroboros Join Date: Nov 2008 Location: Atlanta, GA Posts: 332	Re: GG Shrimp OC cracking pressure I got mine to 1.6, you also need to make sure the IP on the reg you have it plugged into is properly adjusted.
(Offline)

23rd October 2012, 20:35	#4 (permalink)
*jradomski* Moderator Hammehead & rEvo & Custom KISS,Optima,Inspiration,Meg Join Date: Mar 2005 Location: "Da" Bronx Posts: 4,108	Re: GG Shrimp OC cracking pressure Quote: (Originally Posted by jdh) Anyone have numbers for cracking pressure for new Shrimp BOVs? I recently bought a used one and couldn't adjust it to crack until over 4" H2O. I haven't had it in the water yet, but it was terrible at the surface. I took it apart, cleaned/lubed the o-rings and put in a new LP seat and was able to adjust it down to about 3" without freeflowing (adjuster set all the way out). I usually get my Apeks 2nds down around 1.0" doing the same. The valve seat looks good. The shuttle valve 'arms' have a little wear, but look ok. Same for the lever. Any suggestions or is this as good as they get? John I have mine at 1.5 inches.. What is your IP? __________________ 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.
(Offline)

23rd October 2012, 21:06	#5 (permalink)
Silentbob Compatabilist Kiss Classic Explorer #424 Join Date: Oct 2009 Location: New Zealand Posts: 253	Re: GG Shrimp OC cracking pressure Hang on I'm starting to see a trend here, oddly enough its a downsizing trend involving inches.. 1.4" anyone?
(Offline)

23rd October 2012, 21:15	#6 (permalink)
*jradomski* Moderator Hammehead & rEvo & Custom KISS,Optima,Inspiration,Meg Join Date: Mar 2005 Location: "Da" Bronx Posts: 4,108	Re: GG Shrimp OC cracking pressure Quote: (Originally Posted by Silentbob) Hang on I'm starting to see a trend here, oddly enough its a downsizing trend involving inches.. 1.4" anyone? who knows... I just adjusted mine until it free flowed then backed off, when I measured it it was 1.5 " and that was good enough for me... __________________ 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.
(Offline)

24th October 2012, 02:51	#7 (permalink)
jdh RBW Member rEvo Classic KISS Join Date: Aug 2007 Location: Wilmington, NC Posts: 57	Re: GG Shrimp OC cracking pressure Quote: (Originally Posted by jradomski) I have mine at 1.5 inches.. What is your IP? IP was 140 at the time. I tried 120-150 this evening and it didn't make much difference. Took it apart, cleaned everything metal (crown/tube/spring) in the ultrasonic, all squeaky clean. New o-rings. New seat. Balance chamber is good. The lever might be a little bent but seems to function correctly. The little plastic insert in the diaphragm that rests on the lever looks pretty cheap. The counter balance cylinder doesn't look like any of my regular Apeks ones. It has no nipple at all on the end. Is this some variant I've never seen or a Shrimp modification? I adjusted it to where it just didn't free-flow and it now starts to crack around 2.5" It doesn't really start flowing decently until closer to 4" though. It feels like a two-step break. It cracks and barely flows, then at 4", it is actually breathable. I rebuilt two stage regs this evening (DS4s and TX50/ATX50). They both are reliable around 0.8" at 140psi. I can swap the crown & shuttle valve from one of my TX50's in but don't have anything to replace the counter balance cylinder or lever. Any other suggestions? John
(Online)

24th October 2012, 04:16	#8 (permalink)
Silentbob Compatabilist Kiss Classic Explorer #424 Join Date: Oct 2009 Location: New Zealand Posts: 253	Re: GG Shrimp OC cracking pressure Maybe get in touch with Jakub. Without being able to see it/play with it diagnosis is tricky.
(Offline)

24th October 2012, 21:04	#9 (permalink)
jdh RBW Member rEvo Classic KISS Join Date: Aug 2007 Location: Wilmington, NC Posts: 57	Re: GG Shrimp OC cracking pressure Quote: (Originally Posted by Silentbob) Maybe get in touch with Jakub. Without being able to see it/play with it diagnosis is tricky. Tried that... not much help. Is there a shrimp service manual? Quote: There isn’t a manual for the OC portion as it is an Apeks regulator. So same procedures apply. Should it crack like a normal Apeks reg? I have 8 or 10 Apeks seconds and I usually can set them just over 1" H2O Quote: No, you want it to have more resistance as you do not want it to freeflow, ever.
(Online)

24th October 2012, 21:09	#10 (permalink)
Silentbob Compatabilist Kiss Classic Explorer #424 Join Date: Oct 2009 Location: New Zealand Posts: 253	Re: GG Shrimp OC cracking pressure Is there much difference between the spring strength in the Golem as opposed to your other regs? Try swapping out a spring. It's a long shot but the spring in the Golem may be stronger...
(Offline)

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