[Mr T.]

Imported post

Again, just blagged from D-net. But a worthy topic of convo, as some of us will be doing Dotty at some stage (no pun intended) and some of us use the TX range of reg.

JH asks:  

" 46M in Dotty, Apex TX50 on a sidemount, 180 Bar and the valve just stops giving air, felt just as if the cylinder had been turned off. Switched to back mounts then tried again at 30M :- nothing, again at 25M:- freeflowed.

Isolated and then switched back on and it performed faultlessly for 20 minutes. Cylinder, pillar valve and anti debris tube checked:-OK. Nothing obvious on first strip of valve. Anybody similar experience or ideas about failure mode? "

Pertinent as some of us will be doing these drills for real at depth on some of our up-coming courses. Comments and/or thoughts?

 

[Hobby]

Imported post

Bren,Waterfairy was in Probe last year when 2 local(experienced)BSAC divers came in.They were buying new regs having both just experienced similar problems with their Apeks.Feelings aside the TX's have a very good rep and I was a bit suprised to hear this (I mentioned it to John Gulliver at the time)I don't know what the outcome was,maybe you could ask Mark next time you speak to him?
The incident appears to be a case of "freezing" as when the Reg was given a break it became operational again with no probs.This is typical of "freezing" situations.(To be honest I'd have though that the reg would have been designed to freeze open which does'nt appear to be the case initially)
Altough unusual,I suppose all kit has a potential failiure point,we don't know how hard it was being used,what drill he followed before getting in the water(did this happen at the commencement of the dive,had he/she been doing surface drills just before etc?)Many factors can cause a freeflow due to freezing,ask Lawrence and John.Much of it relates to pre dive practice in cold weather.
We can make deductions and assumptions from the info but there's not that much to go on.Hope this helps,Hobby.

 

[MATTBIN]

Imported post

As was answered on the DNet an article published by R. Pyle stated he had similar experience (cant remember if it were Apeks though) and found his first stages on an RB should of had alcohol in them to prevent freezing etc, it had drained/evaporated and caused the internals a problem resulting in exactly this scenario. So may I respectfully suggested the first stages be inspected to see if they have similar arrangements, or see the article I thinks its on DiveOz.com.au under the RB section or see the Dnet link.
Matt

 

[Davey Willo]

Imported post

Bren

Andy Hayhurst (Dalesdiver) and Rob were discussing a similar issue the other day, something that Bret had suffered while we were in Wastwater....

I can't remember the conversation exactly but it was something to do with a certain pin that once greased during a sevice instead of letting air passed as it should, acted at times like a hydraulic ram and completely stopped the reg from working, then it would clear for a while only to do it again...

I'm sure Dales can clear it up, I'll call him later unless you want to.

 

[John Gulliver]

Imported post

I suspect the "alcohol" was in fact ordinary glycol antifreeze and the reg a Poseidon Cyklon, Matt. Mine had a rubber cup containing glycol attached to the first stage with a cable tie and it used to leak at times, so I had to keep replacing the glycol. It's a very primitive form of freeze protection, which isn't surprising considering the reg has been around since the sixties.