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Hello all,
After I broke my shoulder is impossible for me to do shutdowns. I can reach center isolation bot right cylinder is 100% out of question. To use a slob knob is one option the other is inverting twin set. What actually is needed to do so? With twins inverted is it possible to close center isolation? W hoses needs lengthen to accomodated new setup?
Any pro and cons?
 

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Primary and secondary (and maybe your inflator) hoses will probably need to be longer. SPG hose should be fine. Regarding reaching the isolation knob, can you scratch your arse? If so then you can probably reach it too!

May also want to consider a valve guard to protect your pillars when setting the twinset down.
 

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Pierre,

You need to have a convo with both Andy2Tanx and Hobby for this topic mate, seeing as both of them are exponents of the deft art of inverted twins.
 

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Pierre matey!  i'm just about to get off to a funeral, but later today I'll sit down and give you the gen on it.  tbh I have used the cylinders the 'correct' way up for some time and am on the point of going back so... time will tell...  talk later.
 

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Just come back from the Red Sea where I got to try all flavours of dive toys.  So, now I'm a fully-fledged twins convert, and I too want to invert. (Reaching valves in "normal" mode was possible, but awkward). Andy, looking forward to your help...!  Especially interested in hose routing and reg placement.  DIY'd some reg clips out there and it all worked fine, but interested in what other people do.  Quite like, dare I say it, DIR reg placement round neck... Any thoughts?
 

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Reg round neck a la DIR - deffo, I got a good tip from Davey "DIR-tart" Willo the other week, put your bungee or surgical tubing into the cable tie that holds the mouthpiece on, saves a lot of entaglement

Say, Andy, if you're going back to inverts I bet you wish you'd kept your valve guards eh? ;)  
Chee-az
steve
 

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I've been meaning to catch up with this for a while!
Right,'necklaces'.No they're not a DIR invention (Aaaaarrggghhhh)they've been around a long time,neither are they for use only with inverts.As you say surgical tubing,bungee(I like the silicone tubing for aquarium air pumps cause it's cheap and easy to get.)Many people use a good quality para cord or similar though ,downside is that it does'nt give.The necklace is used to stop you losing your reg,and keeping other regs nearby.So close in fact that you can get the regin your mouth without using your hands when it's set up right,just put your head down and it's there on your chest.If you smack your head in a nil vis OH situation(that's why the Brits wear helmets!)you can br disorientated etc.If your reg is'nt on a necklace it can be fatal.OK?
Right twinverts.I picked it up from my Old Man.He adopted into his OW practice from CDG/military setups.i'm not getting into the arqument of whether it's better than the "wrong way up" here,as that's not what's being asked.Many people in conditions exceeeding those I'll ever get into don't use inverts and have a good safe system.However,I like the simplicity of the inverts,I'm not really flexible and there are times I beleive (esp in sumps,OH environments etc)where it maybe awkward to reach behind your shoulders,conversely if you rest your hands behind your back it's a naturally comfortable position.Scratch your bum,think about how easy it is for a moment,now scratch the back of your shoulder blades..sorry do it in the dark,fully kitted up.I just think it'seasier to scratch me bum!
You can route the hoses how you find best.My Old Man's rig has it's one DIN fitting in the normal place between his shouders.An ex-fire brigade fitting(in SS) runs from both DIN valves,up between the tanks to this spot where the 1st stage takes off.He uses one Cyclon with standard hoses in this position.This is the same config as the RN set up but they run their 1st stage from the bottom at cylinder valve level.He used this config in environments with sideslungs however which is where his redundancy came from.
The Police scuba and RN/RE set up uses 1 reg.They work on the principle and practice of manually turning their air on and off if the need arises,in this position it's so easy to do and they do not feel the need to utilise other metrhods.This for me is simplicity in itself,it's probably as basic as you can get,the RN never used contents guages either,using the rule of thirds.
You can make hoses up as I've mentioned before.With independants,you can run the suit inflation etc/under your arm through your harness to keep them neat and out of the way.Run your stage hoses up your back in the space between the cylinders,you can run one under your arm I suppose if you like to donate you "long hose"
I have to go now,Andy 2 tanx will have an interesting input as I think he's going back to the traditional method from inverts.This is (and I'm guessing here)that he's discovered how good a rig can be if it's done correctly the traditional way.That said,there's nothing wrong with inverts,I suppose there are pros and cons with any system.Like everything I'd say suck it and see,if you like it fine and if not well you have a choice,and an informed one at that.I've got a RN Sabre set if anyone wants to borrow it,they'll need to sort a reg out though.like this but without the guards:-
http://www.divernet.com/gear/invert1198.htm
Hope this helps,Hobby.
hOBBY,
 

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Right, here goes.

Firstly, the only downside in my opinion is the extra length required for your hoses.  I actually got a 2m and 3m hose for the regs.  In retrospect, these were probably too long!  All I did was to add another metre to the length of the hoses to take into account the hose going up behind my back.  I think the best thing to do is to measure EXACTLY the lengths you need instead of going to the hose shop and guessing!!

Putting the kit together can be a pain as you have to connect and route your hoses before putting the wing and plate together.  If you don't, you end up disconnecting the 2nd stages to route the hoses up past your plate etc.  Alternatively, you can route everything up the outside of the cylinders using rubber bungees.  I made some out of old car inner tubes!! (Thanks to Gary at Kwik-Fit!)

As for valve protectors, Custom Divers do a set (Steve W, hope they are ok!) for around £100.  Me being me, I am in the process of making some, 'cos thats just the way I like to do things! But I also like the look of the ones the guy has on his set in the inverts article mentioned in Hobby's post, so I may try and copy them...

The length of the dry suit feed is just right.  All you do is stick it under your harness and left arm and it pops out right where the inflator valve is on your chest.

The gauges were too long really.  If you can get them shortened or buy different lengths, then once again, I would measure exactly what length you need.  Not having done that, I coped with them being a bit too long, not such a big deal!

One of the reasons I went to the 'correct' way of wearing cylinders was because I had never tried it with the twins.  Having done both ways, I would say that the 'correct' way is a neater, more streamlined way of doing things, but the inverted way is more practical.  (For me!)  I can't reach my valves with enough regularity to be any use, and in an emergency I would probably just be this great, flapping mess giving off loads of bubbles.  Not good.

I say try it Pierre, you might like it!!
 

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Hobby/2Tanx - I know it's been mentioned elsewhere, but is fitting longer hoses something that anyone can do, or should it be done by an "expert"?

Also, I too would bodge a valve guard - but which bit of the cylinder would it fit to?  Would the valve have to come out?  

OK, maybe this is the Stella talking, but would one tank up and one down mean you wouldn't need valve protectors?!

John
 

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Hi Andy,

any chance of making an extra set of valve guards when you do yours that can change between 10's and 12's please.

Safe diving,
Steve.
 

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OK,valve guards.They sould fit around the necks of the cylinders,being clamped in place there.Probe Diving Services in Oldham had some really nice ones made up in tubular SS by one of the DM's who works with them as he's a fabricator.They were much cheaper than any others I've seen and much nicer.(We were supposed to be trying to get some pics but we've not seen the DM yet!)Their no.is 0161 633 0966
John.You should be fine fitting the hoses yourself,just don't go mad tightening them.A gentle nip is all that's required once they're hand tight.(Remember,many fittings are usually brass/chromed brass.)This maybe a suprise to anyone who's ever run a British bike but it's true.Unsure on your reasoning about the opposed ends not needing guards.You usually lie the twins down as normal and you can still stand them on the bottoms of the cylinders(if you keep the boots handy).
The RN/RE sets have Sabre valves which are designed to take the weight of the cylinders,on big rubber bungs funnily enough(now where have I seen this adopted recently),the control knob also has rubber knobs.Many of the valves widely available on the rec.market cannot approach these in terms of materials,quality etc.and may bend,get FUBAR'd if such weight is put on them,hence the prospect of a guard.(This is probably why the guard is fitted in the Diver article as the Sabres have been removed)In addition to Sabres,similar valves were made by Normalair(?USA arm of:) and Dreager.Sheerwood valves are suppose to be V good,(I'd recommend you speak to Andy Dalesdiver re.good valves that are available).
If you invert,be carefull of falling on your backside which may damage the valves also,you may even cover them in mud!
We really need some pics.don't we.I'll have a look on the net.for some Sabre pics.
HTH,Hobby.
 

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Sorry Hobby, didn't mean to mention the dreaded acronym ;)
Yeah Andy, VPs are fine, I straightened out the bit of a twist they had with the assisstance of a vice.
I'm a bit confused about the routing of the hoses between tanks and BP, surely they'ed get flattened? I reckon I'd go for the 'outside' approach, at least at first.

I like the idea of being able to reach the valves instantly rather than risk  a problem whilst hoiking the wing/tanks/harness up your back.
So think the next items on my dive shopping list are gonna be 2 longer hoses! (roll on pay-day!)
Chee-az
Steve
 

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Steve,the hoses route in the space(roughly triangular)created by laying the twins,down on the backplate(be it a steel or moulded type),As the cylinders are well,cylindrical,you place them together,lay them flat and you're left with a space beneath them yes?
Here's a (not very good) link showing some Sabre type valves(andYes,I know they've left the R out of breathing!).Hobby.
http://www.fittersgroup.com/BeathingApparatus.cfm
 

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I'll have to play around with it i guess, i had instinctively thought that there wouldn't be sufficient space for the hoses due the the BP sitting so far into the 'groove' between the tanks.

Re the link from Diver 1998, I notice the isolator is turned outwards as compared to the current inward facing direction I've got on mine (ie about 150 degrees different), Q: can reorientation of the isolator be done by a reasonably competant mechanically minded person (ie DIY) or is it sufficiently tricky that it requires a qualified scuba technician? I was quite happy doing my own DIN conversion on my apeks 1st stage, my manifold is an MDE
Chee-az
Steve
 

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stripping down the manifold is easy if youre ok with that sort of thing.  obviously the cylinders have to be empty!!
 

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Reckon I'm ok with a spanner (used to be a Toolmaker about a million years ago ie the seventies!), plus I'm intending to get my twins O2 cleaned in the near future so that'd be a good time to sort out the isolator too.
Chee-az
Steve
 
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