V4tec Bov

pchanning

Yet, in your KM48 POD/BOV bracket thread you say:

So how do you know?

What makes it the best Mike?

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Cheers
Paul

The key to enlightenment... is survival.

geordiediver

I rec'd my V4-Tec BOV last Thursday and I have tested it out over the Easter Weekend diving in the dark waters of the Clyde.

First of all I must praise the service of Peter at V4 Tec, the Bov arrived from Germany to the UK 2 days after I placed my order.

The Bov is very well made, and I can't fault the workmanship - German engineering at its best - I particularly liked the rubber cover over the diaphram.

On fitting the BOV, it was impossible to get my Inspiration to hold a negative pressure test (or indeed a +ve test) - the air appeared to be getting in through the mouthpiece - I am not sure how, but when I streched some clingfilm over the mouthpiece, it was definately being sucked in.

Feeling a little nervous about the lack of a satisfactory neg test, I decided to call in to Capernwray on the way to the Clyde to test it out (I gave up on my original plan to test it out on a shore dive on the Kintyre). The BOV worked flawlessly on the 2 dives at Capernwray,and I did not get any water in the loop.

The test on Saturday, was on two wrecks in the Clyde, the deepest being 32m - the swich over to open circuit via the BOV was simple and very quick (even wearing 6mm 3 finger mitts ?) - the Bov gave a nice easy breathe - at least on par with my Poseidon Cyclone. It did however feel a little heavy in my mouth.

Sunday offerred a sterner test - 48m on the bottom of the Kintyre - again the switch to the Bov was swift and easy and stress free - there was no ambient light at 48m - I would not have fancied closing down the original Inspiration Mouthpeice and switching to a normal reg in the conditions. I did not notice any difference in the work of breathing at 48m as compared to the day before at 32m. Moving back the hose weights a couple of inches, cured the "heavy in the mouth feeling".

A couple more dark and dingy dives followed - again no problems with the Bov.

In conclusion - the BOV is great, and gives me lots more confidence knowing that I can switch to OC within a couple of seconds, without any real task loading. The switch to OC is best carried out as a 2 handed affair, one hand to hold the bottom of the BOV and the other turning the switch - single handed operation would be possible - but it would put a fair amount of strain on your teeth. I did not find the depth of the BOV housing caused me any problems in looking down, or side to side - the water would be rushing down the neck seal on my drysuit before the BOV was pushing on my chest. All in all, I am very pleased with my purchase.

Alan

colinicky

Just out of interest have you cured the +/- test problem or spoken to Peter about it ?

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Colin

I trust my rebreather completely ,
I just don't trust the user

onwards & downwards

geordiediver

I rec'd the following response from Peter (rec'd after I went off diving) - I am not sure that I fully understand what he is saying.


"let me make one remark to the denseness testing with the attached DSV:
vacuum test is possible with covered hose-connection of the apeks. (the mp-plug must be isolated.) over-preasure test will have different result. it is possible, that a very little amount of gas passes through the exhale diaphragm of the bailout regulator. this is normal and did not have any disadvantage concerned the divings."

Alan

colinicky

It would appear to me that he thinks it is leaking under - test throu the lp(mp)hose that feeds the apeks bov .ie you didn't have the qc connected ? so let air in ? & that on + test it is escaping via the diaphram on same ?
Obviously when doing tests you must turn BOV in effect to a bailout situation ?
would be interesting to peform a + test in the bath & see were the air is escaping from .

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Colin

I trust my rebreather completely ,
I just don't trust the user

onwards & downwards

decoweenie

If you didn't either:

1. connect the LP hose to the OC reg on the bottom AND leave the tank valve off, or
2. plug the inlet to the OC reg on the bottom somehow (i.e. with a finger)

then it is likely that you won't be able to hold a negative pressure test.

dave t

doesnt this just show that the seal between the OC part and the CC part is leaking? plugging off the second stage wont stop gas leaking from the loop just out of the BOV complete

decoweenie

Yes.

But all of the BOVs I have tried "leak" here since most designs don't have a good seal there.

divetheworld

Thats how I see it too Dave. When the BOV is in OC mode, there should be no leakage between the loop and the outside air.


Turning the gas off and releasing stored pressure in the LP side then doing a neg test. Poz test from the manual inflators works best for me.

My Bob only leaked once, the seal on the swivel needed attention. Since then no leakage at all. Really
Bob fitted 'X' seals to all the moving fittings to prevent seaing problems.

Brent.

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steevke

If the V4Tec valve has no o-ring seals on the cylindrical plug that switches between OC/CC, then it will only be able to hold negative pressure for a very short period of time.

steven