Length of my hose (fnaar fnarr)

[andy2tanx]

Ok  I havent paid the bill yet so I dont know the exact prices.  The AP Valves lead came from Robin Hood watersports near me, they said there was no problem getting one, I presumed they would just get it from AP Valves.

Check out this article for some good pics of a valve protector.  http://www.divernet.com/gear/invert1198.htm
I got a custom divers one but if you could get one like the pic knackled up I would definitely have one at the right price.

[Davey Willo]

I have this particular web page already saved in my Favourites but now It's been brought to my attention again and I've looked more closely at it, There are two things I'm not sure about...
Firstly looking at the big guy wearing the kit, yes he's holding both pillar valves but I bet he can't reach that isolation valve (At least thats the way it looks to me) When he's horizontal and in water, then things might be a little different, but I think to get his hand around and into a position to not only hold, but turn the knob would be nigh on impossible.
My second concern is.... when you look at the 'close up' pic of the arrangement, then that same isolation valve looks very very susceptable to damage.... I can think of a few times where I might of knocked that thing had it been mine....

Seeing inverted twins 'ON' someone and looking more closely has made me reconsider my first thoughts... Methinx I need to investigate further and try peoples kit on.

[andy2tanx]

Good point Dave, could be wrong here but the valve at the end of the manifold is the one that you would turn off in a hurry if you had a free flow.  IF the middle valve is harder to reach though you wouldnt have to get to it in seconds, but could probably have a coupla seconds to get comfy and reach round for it.  In any case, reaching the middle valve there has gotta be easier than getting to it in the middle of your back.  Kapeesh?

[Hobby]

Hi Andy,I've been away for a while and just seen your post,you're right about the inverts,basically the other way up is an amateur config and there's no real reason not to invert.Indeed it should be why don't I invert? Anyway,I'm doing another water safety lecture soon,if you can come I'll bring an inverted twin set(Police configed)that's used with stansard length (Poseidon)hoses.Alternatively get some Aeroquips made up,they're cheaper and of hogher quality usually.I'll get you a no.for reasonably priced Poseidons too and post it tommorow.P.S.See S.Barsky's books fof examples of inverting in industry(all work where BA type apparatus is needed,the recommendation is inverts.) Regards,Hobby.

[Eddie]

OK guys and gals, here goes, call me stupid but, if its normal or better to invert twins, why not invert the singles? (15 or 18 ltr with twin valves)??? then if you have a free flow you can just shut off the offending 1st stage.

[Davey Willo]

Well I'm still not convinced.... it seems that both ways have pro's and con's..

1. Inverted
Dead easy to reach both pillar valves yes, but a nightmare to reach around and turn off the isolation valve, why?? because of the amount of reach needed, the hand wouldn't be 90 degrees to the body anymore, but would actually be palm facing away from the body leaving the knuckled side closest to the isolation valve, making the turning of that valve very difficult, or so it seems
Now at this moment, if you were to swing your arm around to your butt... (Go on try it, u know u wanna) it would appear very easy to reach the isolation valve, but imagine your wing,first stage, hoses and valve protectors all in the way, you have to stretch around all of these obstacles and then your hand will no longer arrive at the same place in the same orientation because of the extended reach.
Check out Andys web link once more, and imagine this guy trying to reach and turn and turn and turn that isolation valve shut.. hes not gonna do it fast enuff, if at all
 
<a href="http://www.divernet.com/gear/invert1198.htm

For" target="_blank">http://www.divernet.com/gear/invert1198.htm

For</a> me, this inverted setup would most definitely require a slob knob for the isolation valve, now that in itself is not a biggy, BUT the 'close up' picture also makes me feel that the isolation knob is in a prime position to get clouted at some time or another and this puts me off this configuration altogether. Add to that, the financial hit of the longer hoses required for the direct feed to the wing/BC and the backup regulator, also an 'absolute' requirement of a valve protector and this becomes even more unattractive, IMHO

2. Valves at top
Looking at pictures 1. and 2. on this link...

http://www.divernet.com/technique/0102twins.htm#top

I think they show that reaching the isolation valve doesn't look too difficult at all, infact picture 2. makes it look a lot easier than I'd first imagined... what DOES look more difficult to me, is picture 3. reaching the bloody pillar valves.. now i'm not sure I'm anything like THAT flexible in my dry bag.. but it appears that this to me is the 'only' con to this configuration against the 'pro's'

Now I'm aware that this is MAJOR 'con' cos if I can't reach the pillar valves to complete a shutdown I'm in deep doodoo, so this is where the doubt about this configuration kicks in.... I know which set-up I like best, but If I'm not flexible enuff to reach my pillar valves in a normal orientation, then my only choice would have to be 'Inverted' with one slob knob attached to the isolation valve. Maybe not my first choice, but maybe my only choice dependant on physical capabilities.

What I need to do, before I spend all of my hard earned pennies is to get together with the likes of yourself, Jay Ammers and others so I can actually get a feel for what I can and cannot do in either rig (inverted or normal) cos everythinng I've just said could be pure tosh, but then its only an opinion :biggrin:

Andy, going back to your original statement of..
&quot;but the valve at the end of the manifold is the one that you would turn off in a hurry if you had a free flow
I'm not 100% sure about this mate, but I think that the first step in an Isolate &amp; Shutdown routine would be to close the isolation valve immediately, thereby preserving the air in one cylinder to hopefully get you back to the surface, and then move on to identifying which side is spewing your air out, shut the offending valve down, and then re-open your isolation valve again... remember, it might not necessarily be an easy to identify second stage freeflow.

On the second link showing the article on shutdowns, the paragraph starting with..
You are at 35M, slightly fuzzed.. gives a good account of how things might happen.. Scary shit!

[andy2tanx]

I think in the words of many a recruit instructor, and probably many pervies you just have to 'suck it and see!'

[Ammers]

Good points Dave on the isolator front and one of the main reasons I would never invert. If the tanks are in the right position on your back you should be able to reach the isolator and the tank valves easily.

[Davey Willo]

Dead right Andy, I just need the opportunity to &lt;ahem&gt; suck it and see...  :shocked:

Hey Ammers
Long time no hear.... how's the blood pressure?? have you been declared fit to dive yet?

(Edited by Dave Williamson at 8:45 pm on April 8, 2002)

[divedog]

[quote]one of the main reasons I would never invert. If the tanks are in the right position on your back you should be able to reach the isolator

Yes.. but you could also find yourself with a KNOB stuck in the back of your head... Fnaarr Fnaaarrr