DIN or A-Clamp

[Nikki]

I am looking a getting my first set of regs. Ive seen some I like (Seac Sub Diamond Ice) and have been asked which fitting I would prefer.

I dived in Lanzarote earlier in year and the tanks had fittings for both but Im concerned as to other diving holidays and diving in UK which fittings are mostly used. My BSAC club only has A-Clamp fitting on their tank but have beeb told I can get an adaptor.

Any help on this would be great?

[Alan Ewart]

Nikki,

Most people would agree that Din are much safer, but in some areas of the world it's not widely available.

All my regs are Din, but I have an a clamp converter in case I need it when on holiday

[Jon H]

its up to you but we mostly every one is going to dim. I got xtx 50 with a xtx 40 octopus and there fine but since the tank is old i have to have a adapter. But i think you should get dim and have a adapter but i wasnt sure what they were on about but ive heard one of them blew of the tank.

[Dave (Simmo)]

Hi Nikki,

i got my adaptor from this supplier on ebay [it was new and cost about £15] - http://stores.ebay.co.uk/Blue-Water-Sports-and-Diving

the thing to bare in mind is DIN is regarded as a better connection than a-clamp not being so vulnerable to blown O rings and the like, however DIN to adaptor to A-clamp is a worse connection [obviously you have an extra connection].

having said that i've never been anywhere UK, Spain, Malta, Egypt, Turkey have all had DIN or A-clamp with removable inserts [i'd recommend you carry the allan key saves the boat rummaging around in the bilges]

Dave

[David Walker]

Yeah I prefer DIN. Slightly smaller first stage and more reliable seal on the cylinder (o-ring kept protected with the reg, rather than on the tank - a-clamp o-rings get lost far more frequently).

The benefit isn't as massive as some make out, but its very rare to go anywhere where they don't have din-convertible cylinders (ie a naturally DIN cylinder, with inserts to make it into a-clamp), and so there's no reason not to go with DIN.

David

[Roz]

I would recommend DIN. I'm a DIN Girl. My Oceanic Delta 3 DX4 has a DIN first stage, as to my other 6 regs (a mix of Poseidon Jetstreams and Cyclons).

When a DIN reg is fitted to a diving cylinder you get a male/female connection, which most divers (and especially engineers) would concur is a very strong connection. Becuase of this design you benefit from a captured 'o' ring. With an A clamp you can suffer from 'o' ring extrusion.

Another advantage of diving a DIN is that the regulator first stage tends to be a lower profile, so it sticks out far less than an A clamp. So less banging of heads.

And in the unlikely event that you ever need to use an adaptor, it's very easy to screw on one in seconds.

[Chris Cherrington]

.. other diving holidays ..

DIN are standard in most of Europe. It is the better choice IMHO.

Chris

[The Professor]

My BSAC club only has A-Clamp fitting on their tank but have beeb told I can get an adaptor.

Nikki,

Unless your club's divers are all using old tanks it might be that they're using a-clamp regs on din-comvertible valves. New tanks have a slug or insert for use with a-clamp regs, you just need to unscrew this with an allen key to use din regs. As others have said din is considered safer.

Dave

[Keith Lawrence]

DIN - every time :) You will probably end up with DIN eventually, they are a much better fitting and if you ever head towards twins you will want DIN on them. I went DIN around 1998, I've only ever had to use my adaptor once when on holiday, most places now have DIN cylinders. http://www.ukrecscuba.org.uk/ukdiver/dinyoke.htm

Keith L

[judithbodkin]

I would have said 50/ 50. I have A - Clamp most of our Club have A - Clamp
again when been aboard I've seen both.:)

[Beanie]

DIN
why? - look at industrial cylinders mostly din valves, welding, gas, etc....

Apart from pin index O2 cylinders I can't think of any that use a clamp system

[Badders (Dave)]

Hi

I was wondering if anyone here knows the background of the A clamp & Din, where did they come from, what are there roots, who invented them and for what? what (if any) are the official advantages, between each fitting?

I have an A-clamp, I didn't choose it, it was just on the Reg when I bought it,2nd hand, most In my club who I've met so far have A-clamps, it seems to be a trusted system. The club cylinders are Din with A-clamp inserts

I must admit DIN to me looks more secure and also looks likes it would leak slower than an A-clamp rather than just totally failing in the event of a breakdown, could anyone enlighten us, would this be the case?

Badders

[Keith Lawrence]

I must admit DIN to me looks more secure and also looks likes it would leak slower than an A-clamp rather than just totally failing in the event of a breakdown, could anyone enlighten us, would this be the case?I've never heard of one breaking, but A-clamps 'fail' in ways that DIN doesn't.

The commonest problem with an A-clamp is the O-ring, they get chewed up, they go missing. But the real problem is when one "pops" (or extrudes) the O-ring, they go with one hell of a bang and a huge rush of gas :) DIN's don't do that, the O-ring is captive and deep inside the fitting. SO I guess you could say that they would leak slower.

Another problem with A-clamp is on boats, people pick up the cylinders by the A-clamp. This can loosen or tighten the fitting. With A-clamp you're only on a single point spike fixing and a bit of rubber O-ring, with DIN the screw thread secures the reg well inside the cylinder valve.

Finally A-clamp are a bit more of a tangle risk, I've had it happen to me and I've freed others :)

There's nothing really wrong with A-clamp, it has worked well for years and as long as you are aware of the problems they will give you good service. But IMHO the DIN fitting is just a better way of doing things.

HTH

Keith L

[Chris Cherrington]

DIN is just a thread fitting, standard on most gas joints. The A clamp (yoke) is a hangover to the old twin hose regs of Cousteau's day IIRC.

Originally the yoke was a low pressure fitment. With the advent of higher pressures (200bar +) it had to be strengthened (very old regs are 3000psi). It will not handle 300bar safely in most people's opinions.

Given the millions of dives done with yoke fittings I doubt you could find much wrong with it to be honest. Technical divers favour the DIN as the 1st stage cannot get knocked off the valve in a wreck or a cave or similar tight situation. Also the O ring failure on yoke fittings tends to fail when the 1st stage is pressurised. High FO2 mixes are pressurised at depth (to prevent accidental breathing) and an O ring failure at that point is a disaster, whearas a failure pre-dive at the surface is simply an inconvenience.

Chris

[mark - sandman]

Captured O ring makes DIN safer. (Nothing worse than kitting up, turning gas on & then have an O-ring blow on an A clamp), except maybe fin strap breaking on a dry suit in full kit ;o)

DIN is also less likely to allow water / moisture ingress to the cylinder & first stage at low cylinder pressures under water.
They can also be used on cylinders up to 300 bar, which A clamps can't. They are a must for most technical agencies (if you intend to go that far).

Very occasionally you may struggle with cylinders abroad only taking a clamp, but its rare & adapters only cost 25-30 pounds each, as someone has already pointed out, they can be picked up even cheaper on E-Bay.

[David Walker]

Just one extra thing, the reason clubs tend to use a-clamp:

With a DIN, if you're careless with it you can cross-thread the thread (hmmm) and if someone tries to force one in at a dodgy angle it can wreck the valve or reg threads. With an a-clamp, the only thing you can really break is the o-ring... unless you hit it really hard.

If you're even vaguely careful, as I expect you will be with your own kit, then none of this should worry you.

David

[Roz]

Hi

I was wondering if anyone here knows the background of the A clamp & Din, where did they come from, what are there roots, who invented them and for what? what (if any) are the official advantages, between each fitting?

Badders

DIN stands for Deutsche Industrie-Norm which translates as "German Industrial Standard", so I suspect that the Germans had a hand in designing this. If so, it is a typical German device. Efficient. Works. Well thought out and designed.

[Badders (Dave)]

Thanx for all the info:D
I live and and learn.

I think DIN looks looks much the better option, I'll have to stick with my A-clamps until I wear em out:rolleyes:

Best of luck with your decision Nikki

Cheers

Badders

[PeteM]

I think DIN looks looks much the better option, I'll have to stick with my A-clamps until I wear em out:rolleyes:

Next time you have them serviced get them switched over, parts are about 20 quid. Labour would be nothing whilst having a service and not a lot otherwise. My LDS would probably do it for free

[Badders (Dave)]

Thanx Peter
I'll check out that option, Just had everything serviced. so a job for next year though.

[iain aitchison]

Hi Nikki,

I would only ever go DIN. The DIN can easily be coverted to A clamp. The A clamp can needs a bulky adaptor with extra o rings. On DIN the critical O ring is yours not what is on the cylinder. Most dive bases operate with cylinders where the cylinder valve has a plug which can be removed to take the DIN. The o ring is imbedded in the DIN fitting and is protected by it. No contest.

regards
Iain

[Nigel B]

Having had 2 O-rings go, thankfully whilst kitting up, I'm thinking of converting
my Apeks A-clamp to a DIN. The instruction manual says the conversion is
simply to buy the relevant piece. Is the job removal from the turret of the
A-clamp and replacing with the DIN parts, or is an adaptor placed onto the
existing clamp? As I'm not qualified with respect to compressed gas and
cylinders, I'm guessing it has to be done by those who are?

[iain aitchison]

Dear Nigel,

the conversion is best a job for your DV service agent, not for a self service at home.

regards
Iain

[Smudge]

Just to add to the flood of replies, DIN every time, and if I had an A Clamp for whatever reason I'd pay the cash to have it converted to DIN.

Almost every diver I know has seen an A Clamp blow a seal, I know no-one who has seen the same on a DIN.....

[Paul Morris]

Just to add to the flood of replies, DIN every time, and if I had an A Clamp for whatever reason I'd pay the cash to have it converted to DIN.

Almost every diver I know has seen an A Clamp blow a seal, I know no-one who has seen the same on a DIN.....
ditto.

My first regs were A-clamp, cause thats what everyone in my club used. "luckily" they were stolen in my first nine months of diving, on the may back from Mauritius. Travel insurance paid out full new replacement cost. What did I buy? Same regs but in DIN.

Never looked back. Do get an A-clamp adapter for the odd occasion you're borrowing a tank with an old style pillar valve.

Trying to get the message through to our new trainees, but there is still an overwhelming nostalgia amongst our club for British A-Clamp vs. German DIN. :D

[Richard Whitcombe]

Having had 2 O-rings go, thankfully whilst kitting up, I'm thinking of converting
my Apeks A-clamp to a DIN. The instruction manual says the conversion is
simply to buy the relevant piece. Is the job removal from the turret of the
A-clamp and replacing with the DIN parts, or is an adaptor placed onto the
existing clamp? As I'm not qualified with respect to compressed gas and
cylinders, I'm guessing it has to be done by those who are?

Did mine about 6 months ago, very simple task with Apeks - definately doesnt need sending away. With Apeks it was basically a case of the right size spanner to undo the nut connecting the A-clamp and just screwing in the new DIN piece with an Allen key.

Quick, simple and easy to DIY.

[Christopher Bullion]

Unlike my club Secretary (Judith, Hi!! :) ), I'm going to say DIN. No question, it's better all round in my opinion. I use a Posiedon 1st and 2nd Stage system, and although it's more expensive, it's the nicest reg I've used.
Hope this helps!

Chris

[clare8448]

My faber cylinder is quite old & has an A clamp fitting. My regs are Apex Tx40 & Tx50 once again far from new (all bought second hand from a diver who was giving up).

How much is it likely to cost me to convert cylinder & regs to DIN?

Is it worth it or would I be better off buying different cylinder & regs?

I have a second hand pony & regs which are both DIN, however I won't be using them until I am more experienced and have practised with them in the pool.

[John Bantin]

Don't rush to switch to DIN yet. You may be buying a new M26 DIN before 2008!

[Michael Purcell]

Don't rush to switch to DIN yet. You may be buying a new M26 DIN before 2008!

I'll believe that when I see it...

It's hard enough to bloody-well get a tank with any sort of DIN fitting when on vacation. I always end up using the A-clamp adaptor which sort of kills the benefits of DIN.

Just start calling air Nitrox 20.95 and be done with it. No need to differentiate between air & nitrox. Just require analysis for everything. And then the Germans(?) can keep their M26 DIN fittings.