simple opv filter mod for boris

Drmike · 31st July 2007, 05:45

I cut some stainless steel mesh into a 20mm diameter disc shoved it into the recess in the back of the opv and secured it in place with a plastic ring (cut to be a tight fit or can be glued)

see pic.

Simple, easy to clean and has an insignificant effect on opening pressure.

The lungs in the pic BTW are prototypes made from same platsic material as APDs lungs

IN468 · 1st August 2007, 18:30

The problems with the OPV mostly come from dust parts of sorb

I´m in doubt if the steel mesh hold back dust and moisture

Stephane · 1st August 2007, 19:37

So the solution is simple: put a scrim filter from APD. Just cut it to the right size and you won't have any sorb particles.
I use one on each cassette of my rEvo and it works very well.

***Decodiver*** · 1st August 2007, 21:19

Quote: (Originally Posted by Stephane)

So the solution is simple: put a scrim filter from APD. Just cut it to the right size and you won't have any sorb particles.
I use one on each cassette of my rEvo and it works very well.

Hi Stephane,

The AP filter has hydrophobic qualities so is not ideal for this application IMHO as the OPV on the Boris serves to also evacuate gunk and fluid etc.

If the OPV is moved to the inhale lung, which has been tried by the factory, then this would be a good idea, possibly.

For your info I use two scrims per scrubber on the rEvo, top and bottom of each one and this keeps everything ship-shape.

Cheers,

Dave Cooper.

Drmike · 2nd August 2007, 01:52

Quote: (Originally Posted by IN468)

The problems with the OPV mostly come from dust parts of sorb

I´m in doubt if the steel mesh hold back dust and moisture

I doubt a lot of things

I am very well aware where the problems come from with my OPV. Im aware because I have two eyes that I use to observe things and a brain that I use to interpret the information my eyes observe.

For example; my eyes observe that my OPV sticks open with grains of sorb (not dust as dust implies very small grains which these are not) Now my razor sharp brain kicks in and reasons that in order for the sorb grain to keep the opv seat from seating the grain needs to big larger than the height of the ridges in the opv (against which the opv diaphragm sits) More of that super neat brain usage combined with those cool eyes things enables me to measure the depth of the ridges (approx 1mm) and thus conclude that the grain size I need to filter needs to be approx 1mm or more in size (i.e. not dust but grains)

Back to the old brain use again I select a mesh size of 0.75mm. So my mesh will stop 0.75mm grains and bigger - no? . Its clear the many times Ive had a OPV leak that the responsible grains are always larger than 1mm (as observed by my sparkling sexy beautiful blue eyes)

Of course I could always just use some of the 0.5mm mesh the 0.25mm mesh the 0.125mm mesh, the 0.72mm mesh the 0.05mm mesh or even the 0.032mm mesh I have - should the 0.75mm be too big....which I doubt.... its not rocket science you know

..and why would I care about moisture??

like to see you keep moisture out of a CL lol!

can we get back to earth now?

Drmike · 2nd August 2007, 02:01

Quote: (Originally Posted by Stephane)

So the solution is simple: put a scrim filter from APD. Just cut it to the right size and you won't have any sorb particles.
I use one on each cassette of my rEvo and it works very well.

Mould growth on scrim, need to remove whole OPV body from lung to clean/replace scrim (which will likely clog up relatively quickly with fine wet sorb dust) and the fact scrim is quite hydrophobic suggests to me at least its not a good filter choice for this application.

SS mesh, just fit it forget about it

Frankie Pellegrino · 6th August 2007, 12:58

After talking with many Boris divers I think that everyboby should put some sort of Filter over their OPV. There are pros and cons to Mike's filter and mine. Because of the design of the Boris' particles can clog the OPV and cause a flood/loop failure.(That's a fact...) After speaking with CCR your kit can handle a good amount of water but....This filter reduces the possibility of a major loop failure caused by the OPV. CCR's OPV Mod has helped but in my opinion a filter is a MUST! I'm sure if CCR were to do another CE test they would use a different style OPV...But it's such a easy Mod, that you should do it! I also recommend the retention band on the canister. I know a few poeple on this site who would love to bad mouth the Boris and its bad points. If I'm diving deep, that's the kit I want on my back. This is a new rebreather and like all new designs, there will be good and bad points.

Mike
Nice filter. In your picture I noticed a new style counter lung. (It looks like a silicone bladder for a standard B.C. Is this CCR's new lung?? Are they Better?
Cheers Frankie

Drmike · 6th August 2007, 17:27

Quote: (Originally Posted by Frankie Pellegrino)

Mike
Nice filter. In your picture I noticed a new style counter lung. (It looks like a silicone bladder for a standard B.C. Is this CCR's new lung?? Are they Better?
Cheers Frankie

Too early to say. Ive only had them a while. Ill see how they perform next week in Florida caves - yeah! baby!

. They are CCRBs prototype ones Ive been given by them to test. I agree Boris is still the best Rebreather for big dives.

1st August 2007, 18:30	#2 (permalink)
IN468 Custom Title Allowed! Current Rebreather/s: Ouroboros Other Rebreather/s: Inspiration Classic Join Date: Feb 2006 Location: Bavaria Posts: 141	Re: simple opv filter mod for boris The problems with the OPV mostly come from dust parts of sorb I´m in doubt if the steel mesh hold back dust and moisture
(Online)

1st August 2007, 19:37	#3 (permalink)
Stephane Stéphane Acounis Current Rebreather/s: rEvo Other Rebreather/s: rEvo Join Date: Nov 2005 Location: Nantes - France Posts: 769	Re: simple opv filter mod for boris So the solution is simple: put a scrim filter from APD. Just cut it to the right size and you won't have any sorb particles. I use one on each cassette of my rEvo and it works very well. __________________ Stéphane
(Online)

1st August 2007, 21:19	#4 (permalink)
*Decodiver* Administrator Current Rebreather/s: Other CCR Other Rebreather/s: Other CCR Join Date: Jan 2005 Location: Geneva Posts: 2,181	Re: simple opv filter mod for boris Quote: (Originally Posted by Stephane) So the solution is simple: put a scrim filter from APD. Just cut it to the right size and you won't have any sorb particles. I use one on each cassette of my rEvo and it works very well. Hi Stephane, The AP filter has hydrophobic qualities so is not ideal for this application IMHO as the OPV on the Boris serves to also evacuate gunk and fluid etc. If the OPV is moved to the inhale lung, which has been tried by the factory, then this would be a good idea, possibly. For your info I use two scrims per scrubber on the rEvo, top and bottom of each one and this keeps everything ship-shape. Cheers, Dave Cooper. __________________ CCR/OC Trimix Instructor Trainer CCR Training to Mixed Gas in Switzerland, France, UK & Germany on Megalodon/COPIS-Megalodon/KISS/Sport KISS/Ouroboros/rEvo/Inspiration/Evolution/Sentinel www.zerogravitydiving.com Rebreather World Terms & Conditions Last edited by Decodiver : 1st August 2007 at 21:22.
(Offline)

2nd August 2007, 01:52	#5 (permalink)
Drmike Custom Title Allowed! Current Rebreather/s: MK 15.X Ouroboros Other CCR Home Build Other Rebreather/s: Inspiration Classic Other CCR Home Build Join Date: Feb 2005 Posts: 3,325	Re: simple opv filter mod for boris Quote: (Originally Posted by IN468) The problems with the OPV mostly come from dust parts of sorb I´m in doubt if the steel mesh hold back dust and moisture I doubt a lot of things I am very well aware where the problems come from with my OPV. Im aware because I have two eyes that I use to observe things and a brain that I use to interpret the information my eyes observe. For example; my eyes observe that my OPV sticks open with grains of sorb (not dust as dust implies very small grains which these are not) Now my razor sharp brain kicks in and reasons that in order for the sorb grain to keep the opv seat from seating the grain needs to big larger than the height of the ridges in the opv (against which the opv diaphragm sits) More of that super neat brain usage combined with those cool eyes things enables me to measure the depth of the ridges (approx 1mm) and thus conclude that the grain size I need to filter needs to be approx 1mm or more in size (i.e. not dust but grains) Back to the old brain use again I select a mesh size of 0.75mm. So my mesh will stop 0.75mm grains and bigger - no? . Its clear the many times Ive had a OPV leak that the responsible grains are always larger than 1mm (as observed by my sparkling sexy beautiful blue eyes) Of course I could always just use some of the 0.5mm mesh the 0.25mm mesh the 0.125mm mesh, the 0.72mm mesh the 0.05mm mesh or even the 0.032mm mesh I have - should the 0.75mm be too big....which I doubt.... its not rocket science you know ..and why would I care about moisture?? like to see you keep moisture out of a CL lol! can we get back to earth now? __________________ Cave diving is a sport Wreck diving is a sport Diving in general is a sport 'Rebreather diving' is not a sport its the delusional obsession with a highly dangerous and often inappropriate piece of equipment
(Offline)

2nd August 2007, 02:01	#6 (permalink)
Drmike Custom Title Allowed! Current Rebreather/s: MK 15.X Ouroboros Other CCR Home Build Other Rebreather/s: Inspiration Classic Other CCR Home Build Join Date: Feb 2005 Posts: 3,325	Re: simple opv filter mod for boris Quote: (Originally Posted by Stephane) So the solution is simple: put a scrim filter from APD. Just cut it to the right size and you won't have any sorb particles. I use one on each cassette of my rEvo and it works very well. Mould growth on scrim, need to remove whole OPV body from lung to clean/replace scrim (which will likely clog up relatively quickly with fine wet sorb dust) and the fact scrim is quite hydrophobic suggests to me at least its not a good filter choice for this application. SS mesh, just fit it forget about it __________________ Cave diving is a sport Wreck diving is a sport Diving in general is a sport 'Rebreather diving' is not a sport its the delusional obsession with a highly dangerous and often inappropriate piece of equipment
(Offline)

6th August 2007, 12:58	#7 (permalink)
Frankie Pellegrino Custom Title Allowed! Current Rebreather/s: Classic Kiss Ouroboros Other Rebreather/s: Inspiration Classic Join Date: Jan 2006 Location: NYC New York Posts: 134	Re: simple opv filter mod for boris After talking with many Boris divers I think that everyboby should put some sort of Filter over their OPV. There are pros and cons to Mike's filter and mine. Because of the design of the Boris' particles can clog the OPV and cause a flood/loop failure.(That's a fact...) After speaking with CCR your kit can handle a good amount of water but....This filter reduces the possibility of a major loop failure caused by the OPV. CCR's OPV Mod has helped but in my opinion a filter is a MUST! I'm sure if CCR were to do another CE test they would use a different style OPV...But it's such a easy Mod, that you should do it! I also recommend the retention band on the canister. I know a few poeple on this site who would love to bad mouth the Boris and its bad points. If I'm diving deep, that's the kit I want on my back. This is a new rebreather and like all new designs, there will be good and bad points. Mike Nice filter. In your picture I noticed a new style counter lung. (It looks like a silicone bladder for a standard B.C. Is this CCR's new lung?? Are they Better? Cheers Frankie
(Offline)

6th August 2007, 17:27	#8 (permalink)
Drmike Custom Title Allowed! Current Rebreather/s: MK 15.X Ouroboros Other CCR Home Build Other Rebreather/s: Inspiration Classic Other CCR Home Build Join Date: Feb 2005 Posts: 3,325	Re: simple opv filter mod for boris Quote: (Originally Posted by Frankie Pellegrino) Mike Nice filter. In your picture I noticed a new style counter lung. (It looks like a silicone bladder for a standard B.C. Is this CCR's new lung?? Are they Better? Cheers Frankie Too early to say. Ive only had them a while. Ill see how they perform next week in Florida caves - yeah! baby! . They are CCRBs prototype ones Ive been given by them to test. I agree Boris is still the best Rebreather for big dives. __________________ Cave diving is a sport Wreck diving is a sport Diving in general is a sport 'Rebreather diving' is not a sport its the delusional obsession with a highly dangerous and often inappropriate piece of equipment
(Offline)

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