Hookah 12Vdc direct drive air-line diving system

  • Thread starter Thread starter Anonymous
  • Start date Start date
Re: Tubi-grip

[ QUOTE ]
I suppose this was very dodgy, was it?

[/ QUOTE ] Yes.

Two problems, firstly snorkels are about 18" for a good reason, to stop you breathing air at atmospheric pressure whilst your body is surrounded by higher water pressure. Not good for the lungs. Secondly longer snorkels means that you are breathing the same air back in that you just breathed out so it not being changed. This gives you two further problems, you will start to breath more quickly and deeper as the carbon dioxide builds up in your system, plus the oxygen level falls as you use it up. If it drops to 16% from a normal 21% then your in trouble but it will support life (this is how artifical ventilation works). If it drops lower then you will black out, underwater, not good and you won't know its happening. Sorry for the bad news.

Pete
 
Hi Lemain

Yes looks OK. the compressor looks the same as the one I carry in my car to pump my tyres up but I am positive it isn't.

I would like to know what is special about the Hookah regulator and the difference with a normal stage 2 SCUBA regulator.

Regards

Roger
 
Thanks Pete, and I appreciate your input. I do think that you seriously underestimate the problems facing the liveaboard cruising yachtsman without a car who wants to get an air bottle filled. If I want to have cylinders filled, how would I get them to a dive shop without a car? By taxi? At anchor, load the bottles into the tender, struggle with them up to a main road and try to find a phone box or take them on a bus? It really is far more difficult that you seem to realise and I can only imagine that you are coming from the perspective of a UK yachtsman with a car, a recreational diver, in cold UK waters? Not a liveaboard yachtsman at anchor in the warm Mediterranean without a car who wants to pop over the side to do a hour or so scrubbing, etc.

If you check out the links I have posted you will see that to carry cylinders will take up at least three times the space of a medium compressor and about ten times the space of a small "pressurised snorkel" type. Space is at a huge premium when living aboard.

As for filters, the reason why dive compressors for filling cylinders need special filters is because some compressors use oil and because when you fill a tank you have to be more careful of the purity - there are standards to meet. Yes, hookahs use standard compressors used in workshops and paint spraying but are you suggesting that a compressor has to have "Diving" engraved on it before it will be safe? If you did insist on that (which would be very much in tune with Spanish mentality) it would be an identical thing with a different label, because all we are looking for is clean compressed air. If there is no oil in the compressor then there can be no oil in the air. It is sensible to put an in-line filter in to catch any particles that shouldn't have got in there - that's commonsense but probably not essential.

You say that air doesn't go stale. I studied diving in great detail in the mid 1970s and took diving lessons in Malta. I am not greatly experienced but I have covered the theory and I do remember that air should not not be used indefinitely. The following comes from http://admdiving.net/Library/Does-Air-Go-Stale.aspx
[ QUOTE ]
Does Air Go Stale
A Good Question - If we all adopt the advice i've seen from NOAA, NASA, UK MoD and DAN then the consensus of opinion is 6 months.

Now the numerous elemental and molecular parts of air - by themselves in a scuba cylinder don't delaminate nor deliquesce. However dewing may be possible at the extremes. The problem is that the container is largely inert, however still slightly reactive to oxidation and hence very minor rusting (for steel). That said Iron Oxide (Rust) doesn't itself pose any major risk nor significant odour to turn Air Stale. Even though you can decant Oxygen and other gases and keep these longer, the problem seems to be with the Hydrocarbons.

You have to look further at the Hydrocarbons and unfortunately some compressors do have oil in them - and no matter how well filter - a small trace level (and trace level of byproducts) such as Carbon Monoxide, Carbon Dioxide and other Hydrocarbons will in tiny levels be present. It is believed these cause the air to go 'off'. In the main if water vapour is to the HSE standard DVIS 9 (EN12021) then chemical reactions with the Steel or Aluminium will be very negligible. The Nickel Plated Phosphor bronze and Nitrile Rubber, PTFE and Stainless Steel components of the Valve are inert at these pressures and storage temperatures.

Personally Stick to the practice of 6 months and a year for 100% O2 - its a sensible and good rule of thumb, for the price of a fill is your life really worth a few quid? Take them to a reputable dive shop for refilling - drain them completely before you go there. Ask the dive store how does he know when to change the filters - total and utter bull.........

[/ QUOTE ]
 
Okay, take the point if you haven't got a car, but a bike would keep you fit and what else does an expat do during the day? not that I am jealous or anything driving to work in the rain and dark for the next 6 months /forums/images/graemlins/grin.gif

So if your going down the home made stuff, why not use the second stage of an ordinary regulator. Lots on e bay. A normal regulator has two stages. The first stage that connects to a cylinder takes high pressure air at over 200 bar and reduces it down to 10 bar above ambient pressure, about 10 bar at the surface depending on model. Your compressor suggests a max pressure about 9 bar which is pretty close. So you need a long hose 10m ? capable of taking the working pressure plus a good safety margin, (presumably the compressor has a blow off valve fitted). This will have a second function in that whilst the compressor gives a steady supply you need 30 lpm but in large gulps. Max lung function for the average male is 4.5 litres by the way leaving 1.5 litres of dead space. The long hose will therefore act as a acumulator just like your pressurised water system. Do you have a good hose firm nearby, if so connecting the two hoses together shouldn't be a problem.

You can buy (just sold one) small personal filters for diving equipment, with the carbon disposable filters.

Final thought for the moment please do buy a divers weight belt, one hand, quick release, and your on the surface.

Pete
 
Hi Roger,[ QUOTE ]
I would like to know what is special about the Hookah regulator and the difference with a normal stage 2 SCUBA regulator.

[/ QUOTE ]I first came across the issue here
http://reviews.ebay.ca/hooka-scams_W0QQugidZ10000000002716499 and then found another couple others that I can't find right now. I found that most standard scuba regulators expected a pressure of 140psi, which is much higher than we might have under load. I found a comment that hookah regulators accept much lower pressures. I wish I knew the answer myself. As for the two-stage part, that seems simple enough in that the first stage regulator reduces from 3000 psi to 140 psi. The question is what is the design difference between the hookah second stage and the scuba second stage and why would you want an adjustable second stage?

I am now going full circle again back to the product I came in with as it is only another 400 dollars but it has a much more powerful compressor and has a longer 60' hose. I found a report online about the Brownie's pressurised lung from an otherwise happy user who commented that 25' is too short for the hose. I think he's right - my yacht is 42' and it is going to be a bit of a pain with only 25' of hose. I would much rather have 60' - nothing to do with the depth, just the ease of use.

If you come across the answer, please share it with me!

David
 
Pete,

"Home made stuff"?

I think maybe you are not actually reading the posts? My original post was a proprietary hookah system and with the exception of an alternative compressor all of the components in the links I have posted are proper diving shop components. As I said in an earlier thread, there appear to be no hookahs in the UK and I suspect that the BSAC who are the thought police on all diving matters in the UK are to blame. But if you go to the US there is a huge choice of properly made hookah kit. However, the electric US compressors are 110V/60Hz and that is always a pain to convert so it would be easier to buy an appropriate compressor in the UK or Europe. Also less weight to send over.

Re scuba second stages please see my message (adjacent) to Roger. There is this comment about it failing open (they don't explain why, or how) but also we know that the correct pressure for the scuba regulator is 140 psi and we would expect 70 psi or below from our 116 psi workshop-type compressor. The Brownie's is said to be adjustable, maybe with your experience you could deduce why they would want to do that?

As for accumulators, I think that I will add a 10 litre accumulator as per the link in the OP. It is very light and stainless, and I have a spot for it in the engine room. They claim that this makes their system good for two divers (or pressurised-snorkel users which is, maybe, a better term?) - I have my doubts about that but it should be good for one user.

As I said earlier in this thread, I do have a weight belt already which I use when free-diving and working on the boat. Without it I bob up and don't have the energy to stay down! Yes, it is a standard one-handed quick release belt with standard lead weights.

I have been trying to understand why Brits have such a hate for hookahs. My suspicion is that it is because the BSAC is all about recreational diving and hookahs would be dangerous diving over interesting things - geological or artificial - on the bottom. It would be very easy for the hose to get snagged and with several divers it could be mayhem knowing whose hose was whose. So for weekend divers hookahs would be inappropriate whereas from first principles it is clear that they are ideal for the cruising couple living aboard and wanting the kit only to work on their boat or recover things from very shallow depths. Does that make any sense or might there be another reason? There has to be a reason why US suppliers of hookah gear don't offer any of that product in the UK - could it even be illegal?

David
 
I have one and use it regularly at anchor, despite having scuba gear on board too.

Divers in marinas here also use this system rather than trailing around with cylinders. In these waters a monthly bottom scrub is needed, sometimes with a two week water line clean up. For a cruiser to carry enough air to keep on top of this, it would require having a compressor on board.

Unless of course you purchase a bicycle to add further to the dive kit needed and cycle the 20 or so miles to the nearest dive shop for a fill every other week!

Great piece of kit, easy to use and, if trained, safe and convenient.

Paul
 
Hi David
Found the manual I have a deck snorkel we use it constantly very good for all kinds of boat maintence we ordered a extension hose but have never used it boat 13 mtr.
Sorry unable to tell you the price of the unit dont keep invoices tells me how much we spend on the boat.
We have never found it under powered it is suitab;le for the job I will keep in contact you might be able to test it yourself.
 
"and of dubious safety from a health point of view (constantly holding my breath)"

Hi Lemain...Other posters here seem to know a lot more about Hookahs than I do, but under 10 metres depth you won't have any problems really as you're only breathing at 2 Atmospheres & you could spend several hours underwater. You wouldn't be spending more than 30 minutes at a time underwater with the Hookah anyway would you.? You'd probably want to come up & have a cup of tea & a warm-up by then.?
The Hookahs I've seen being used over the years have had a small Honda petrol genny on top of an inflatable rubber tube, but I haven't checked to see if Honda actually put out a 'hookah-kit' as such, or whether one has to source the compressor etc..separately, & assemble the thing oneself.

Re' being 'of dubious safety-constantly holding your breath', I wouldn't worry about that at all if you're in pretty good health, as that activity is very good for developing ones' lung-capacity. I started spear-fishing 35 yrs ago & found that within a few short weeks I could stay down for several minutes. Just don't start hyperventilating before you dive under the boat, otherwise you could 'black-out'.
Jeff
 
I suspect the BSAC are worried because hookas tend to be marketed to non divers without training. There is a very good publication called "safe diving practices" published each year by the BSAC. However the lessons that have led to these recommendations have had to be learnt the hard way. They are keen to encourage diving, but in a safe and enjoyable way.

Pete
 
There are lots of things marketed at people without training - you can go out and buy a Sunseeker 60' with big engines and proceed down Southampton Water at a great speed! That isn't a good enough reason to be anti-Sunseekers!
 
I've read about these: freediver and they seem to do just what you want- albeit a little expensive! On the other hand I reckon they'd have a very hard time if marketing an unsafe and potentially lethal device within the EU. Same might apply to Brownie's third lung having the US legal system in mind, eh?
 
That's the first EU source I've seen so far but given the present value of the dollar I would buy from the USA for sure. Also, freediver don't give anything like enough information to make a purchasing decision.

I agree with you about legal liability. The US websites all make it clear that you should have a diving qualification and one of them offers an online course. Not instead of a proper course, but presumably having recognised that quite a few customers will not have received formal training. In a country with no compulsory boat training and where you can buy a heavy fast speedboat without training and go straight to sea with passengers, I can't for the life of me see why you can't buy a hookah system! I'd bet that there is something preventing dive shops from selling them in the UK.

If anyone reading this thread personally knows a UK dive shop owner or manager, could they please try to find out why you can't buy hookah systems in the UK?
 
David,
Still following this most interesting thread.
FYI I've found this site.

http://www.powerdive.com/distributor/europe/spain

You may have come across it already , but it appears they have a Spanish agent.
Personally I'm not over the moon about thier system. Like the German one it doesn't give much technical info. But as it's (relatively) close you may be interested.

Cheers
Cliff
 
Cliff - Thanks. I know both those products and both are quite interesting. They are priced in AUS so I have emailed the chap in Barcelona for prices and delivery. Many thanks. Interestingly, the US manufacturers have not given me his details!

Pete - Thanks, he is not showing a hookah product on his website now. If the general feeling about hookah systems is as endemic in the BSAC as seems to be the case, then that would explain it.
 
I have now found the info on biulding yourown hookeh diving kit.

The website I downloaded it from now has changed and now only shows the equipment.
starting here

If you PM me your e-mail address I can e-mail you the html page and pics I have or

here are the DIY instructions I found web page
 
No personal experience, but I looked into this matter some time ago. One of the important points seemed to be that you need to COOL the air, as compressing it will heat it up. A site which might be of interest to you is: www.seabreathe.com This is a Canadian firm with Spanish agent.
 
That is a very interesting product, thank you. The receiver is unique in being an inflatable device whereas all the others have steel or plastic cans which take up a lot of space or no receiver at all. The Spanish agent seems to be asking sensible prices...all the Spanish agents of the other manufacturers seem to think that they can double or treble the US selling price and get away with it. Another interesting feature of this product is that the two diver Deck Unit can be used by one diver with double the length of pipe.

Another interesting and seemingly unique feature of this product is a variable pressure output so the pressure falls down as low as 20psi when diving at shallow depths which will significantly reduce battery consumption and waste heat. It is a diaphragm pump which is also unique, all the others use PTFE sealed piston compressors. Diaphragm should be quieter. We are not told the compressor output power but the website presentation gives a credible impression and I imagine that it does what they say it does, which, frankly, is all I care about.

Regarding cooling, yes the output from all air compressors gets hot but almost all of these hookah systems rely on the heat being dissipated in the hose (not unreasonable) though one of the more powerful units has a short length of special heat-dissipating hose immediately after the compressor. The more work the compressor does, the hotter the air.
 
You must log in or register to reply here.

Share this page

Top