leaky manifold

[chris_t]

hi,

My 2nd hand twinset was delivered this morning (thanks Frank) and I came to fit it to my backplate and wing tonight.

1st thing I noticed was length of bolts, a little short, but not to worry, I have some stainless threaded rod.

I cut 2 pieces of M8 rod to go through the bands (unknown brand) and found that the bottom rod came out fine, but the top one was well stuck, the top of the tanks are closer than the bottom.

I tried loosening the manifold slightly to widen in, no leak. Got the threaded rod through, no leak.

As I tighten back the manifold, making sure the tanks are square, no stress on the manifold, it starts to leak!

What have I done wrong, and how do I remedy it? I know its gonna cost me 12 quid in nitrox, just glad I haven't screwed an expensive trimix fill!

Pls tell me I haven't bust the manifold!

Thanks in advance!

Chris

[ardhill]

Sounds to me like it may be misaligned e.g. the bands are bringing the tanks together at a different distance than the manifold is. Thus you have a strain on the manifold holding it at a slight angle.

Or it could be that the manifold is dodgy and the previous owner had it set to look ok, maybe using PTFE tape on the threads or something?

But I am not a technician - not even near, so hopefully someone else will give you a bit more qualified input.

[Twinsetmad]

You'll have to take it all to bits and check the o rings...somathing has gone or is badly out of shape....what manifold is it.. If its MDE its probable just not tight enough...if its a barrel o ring type you may have split an o ring...If you'd done it empty you may have been alright....I never touch mine when they are full...decant some into another cylinder...then when you think you;ve fixed it you can decant back to test... or what will happen is you'll put ity back together and take it for a fill and it will still leak..good luck

[chris_t]

I'm gonna take it to SDS, it will be quicker, and safer!

It is an mde valve, and leaks more if I tighten it more ??

Chris

[pauldiving]

chris what brand of manifold is it?

i think you should drain any pressure off slowly so you dont get any problems,

the dive shop-supplyer shouls sort this out for you,

did you essemble the set yourself?

it may just need a pinch up to tighten but dont do this under pressure as it could damage the little o-rings " i did this" ! nearly lost my hair!

if the sets straight and tight you shuold be able to mount your backplate without any bending or forcing,

[chris_t]

Ok, SDS have looked and said the bands are crap, which I believe.

Before I started to replace the threaded rod, I could see there was a bigger gap at the bottom of the cylinder.

Arthur is very kindly making me a set of bands suitable for the mde manifold.

Maybe I should have bought a set of brand new twins, its gonna cost me the same when i've refilled them

Anyone got a set of twins to borrow for stoney cove tomorrow??

Thanks for your help,

Chris

[Twinsetmad]

Hi Chris... its good its MDE..you will have to drain them off...but a simple tighten up should do it...just to reseat the o ring...there shouldn't be any damage done..but you can't tighten a manifold up with air in..

[Rob Dobson]

Originally Posted by chris_t

Anyone got a set of twins to borrow for stoney cove tomorrow??

Where are you based Chris?

[chris_t]

Hi rob,

I'm in Sheffield,

Chris

[Rob Dobson]

Originally Posted by chris_t

Hi rob,

I'm in Sheffield,

Chris

Ah - OK, not exactly on my way down to Southampton from Oxford then! I could have dropped a set round but Sheffield is a little out of my way!