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Discussion Starter · #1 ·
Hi All,

Just had a interesting day at Gildenburgh today. Built my Inspiration, carried out all pre-dive checks and executed the Pre-breathe (Everything normal). After the pre-breathe - I came off the loop and out of the rebreather /harness for a few minutes to help my buddy kit up.

When I put my RB back on, I noticed that I had lost 40 Bar of O2! and that the counter lungs were fully inflated - venting from the lung dump valve. I closed the O2 cylinder valve and took my inspiro back off again and inspected the unit front and rear Manual O2 valve stuck - No! - Leaking from 1st Stage - No! Jammed Soleniod perhaps?

I turned on the O2 valve again so that the gauge read 140 bar and turned it off straight away - the gauge needle fell steadily to 0 Bar in less than a minute. I then switched the unit off at the handset (Vision) - Opened the O2 valve and again shut it off straight away. This time pressure in the gauge stayed!

I then switched the unit back on and re-calibrated - Fault disappeared. Everthing functioning normally!

I decieded to dive restricting the max depth to 15m watching my PPo2 like a hawk. 30 minutes into the dive I suddenly experienced +ve bouyancy. Checked PPo2 - Rising through 1.4 peaked 1.48. DIL flush - 02 cylinder off - brought PPo2 down to 1.2 and finnished the dive with manual control of the o2 valve.

After a surface interval - Changed both of the Units batteries as the Energisers was showing early signs of decay (5.45 and 5.6v respectively - and just wanted to illiminate remote chance of these being the problem) - I again completed all pre-dive checks successfully including pre-breathe (with the intention of conducting the whole dive OC bailout but putting the rebreather on to observe its behaviour (again intermittant high PPo2)

I guess my head needs to go back to APD for investigation - but would be interested to know if this has happened to anyone else? :sad:
 

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What solenoid do you have old/new type I've had it on the old type that if you turn it the wrong way (when messing about with the cells) that it can cause a leak? Also might be worth stripping/cleaning the manual o2 inflator


Sent from my iPhone using Tapatalk
 

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As "Thermocad" said, it sounds like the components in the lid need tightening up, certianly need to be checked.
Might be the solenoid itself has a leak.
 

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Unplug your manual O2 inject hose and then go through your pre-dive checks again. This should eliminate whether it's your solenoid stuck open or O2 is leaking in through the Manual Add... which is what I suspect is happening. Also if you unplug your Manual O2 inject hose and try a negative it will probably fail as air will vent in through the O2 nipple which means the manual add valve is stuck open.
 

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Unplug your manual O2 inject hose and then go through your pre-dive checks again. This should eliminate whether it's your solenoid stuck open or O2 is leaking in through the Manual Add... which is what I suspect is happening. Also if you unplug your Manual O2 inject hose and try a negative it will probably fail as air will vent in through the O2 nipple which means the manual add valve is stuck open.
I like your methodology but I have never known a manual inflator jam open, the O ring could be damaged but that would be extremely unlikely - depends on the age of this inflator and when it was last serviced etc etc.

We've been producing that design of inflator internals since 1974.

If the internals start sticking, it's easy to take apart, clean and lubricate.
Points to remember: a) The push button has a nylock effect, so it's best to replace the button if you take it apart. b) the button top should be flush or below the rim of the black moulding, never proud. If it is proud, it either hasn't been done up enough or is coming loose.
 

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A short fat well off crap cave diver. Likes wrecks
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Unplug your manual O2 inject hose and then go through your pre-dive checks again. This should eliminate whether it's your solenoid stuck open or O2 is leaking in through the Manual Add... which is what I suspect is happening. Also if you unplug your Manual O2 inject hose and try a negative it will probably fail as air will vent in through the O2 nipple which means the manual add valve is stuck open.


What he said

Also did they show you how to service the solenoid on Mod one. Or don't they do this anymore?

If in doubt then let the professionals look at it but try the manual 02 add first because thats nothing to do with the head, so sending it back wont help.

ATB

Mark
 

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I like your methodology but I have never known a manual inflator jam open, the O ring could be damaged but that would be extremely unlikely - depends on the age of this inflator and when it was last serviced etc etc.
I've seen twice inflators sticking open, but admittedly they've both been Dil Manual Adds... but physically the same types of valves. Both just needed a strip, clean re-grease.
 

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A short fat well off crap cave diver. Likes wrecks
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As "Thermocad" said, it sounds like the components in the lid need tightening up, certianly need to be checked.
Might be the solenoid itself has a leak.


Thats a bit confusing Martin. The Solenoid is surely the only thing in the head which can leak 02 into the unit.

The gland where the solenoid penetrates the head should not be an issue for 02 so hasn't it got to be gas coming past the internal seals of the solenoid? Is there a seal between the gland and the solenoid its self that can fail? I don't remember one.

All of which i find a little unlikely and am more inclined toward the manual 02 add. But id still strip and clean the solenoid just in case.

Either that or its an electronics issue and the solenoid is working fine and the unit is over injecting 02 due to a hand set failure.


ATB


Mark
 

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Discussion Starter · #11 ·
High o2 today

Thanks for your responses - just to clarify:
o2 was being injected by the solenoid - not the manual inflator.
The soleniod is a new low power type (fitted last year I think).

Should I have a look at the compnents myself or would it be wise to send it to the factory?
 

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A short fat well off crap cave diver. Likes wrecks
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Thanks for your responses - just to clarify:
o2 was being injected by the solenoid - not the manual inflator.
The soleniod is a new low power type (fitted last year I think).

Should I have a look at the components myself or would it be wise to send it to the factory?

If its the solenoid its self all you can do is strip it inspect for corrosion or damage, lube it and re assemble. Also i assume you checked the IP on the first stage?

I have never seen the new LP one but on the old one this wasn't a problem

If you don't feel confident doing this then send it back.

If you cant find a problem but it still lets by, send it back.

If its less than a year old and still under warranty send it back because you will probably invalidate the warranty by stripping it your self.

ATB

Mark
 
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Discussion Starter · #15 ·
Thanks - I'll have a look tonight. If at any point I feel that I'm out of my depth - I'll send it to APD for a look. I'm not sure how old the soleniod is as the head was replaced FOC 'out of warranty' last year due to controller 2 not turning off and draining the batteries (another example of great service from APD).
 

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I had a similar problem a couple of years ago but the leak was quite small. When the unit was standing after calibration the PPO2 would gradually drift up. I did not see it as a problem as the leak was well below my metabolic rate and did not cause me a problem while diving, other than the additional anxiety. I proved the leak to the solenoid not shutting fully by blanking off the O2 hose to the solenoid, with a valve second stage, leaving all other connections in place. The problem fortunately cleared during the series of dives I was doing, I have been fortunate not to have it repeat. I concluded it was contamination on the seat of the solenoid, I now cap off the inlet when I remove the hose.
 

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First thing I'd reach for is the IP gauge.
The solenoids are not good at switching off if that's to high.
 

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Discussion Starter · #18 ·
High O2

Just checked the IP's - Normal. I dont like the idea of stripping down the solinoid so I'll send it to APD to be safe :)

Thanks for your reply's - Andy
 

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