Leading Edge Gas System
 The system took seven months to manufacture and install. We took a long hard look at the system failures and accidents through out the industry and designed in many key safety features for all our benefit.
We designed the system in conjunction with the RIX manufacturer and service agent in the UK - HSM Engineering Technology Ltd (Tel 01509 211233 or 07801 340096). They did a stunning job and were highly professional.
A key feature we designed in from day one was non-return valves on each air filling whip to prevent mixing of air from other peoples scuba cylinders. So all you get is clean air as there is no cross mixing nor potentially cross contamination of air between cylinders.
Another key feature besides all the subtle safety features was the rate of filling to ensure good fills and fills that do not get too hot.
These non-return valves on the air whips prevent a near empty cylinder being rapidly filled from a much fuller cylinder on the adjacent whip (and hence huge adebatic heating implications for the near empty cylinder), leading to a poor fills when cool.
At the end of the day its still down to good ownership and care of the scuba cylinders themselves. Ensuring that they are serviced well and never allowed to drain completely - certainly not below 20 Bar. If it does go below this level take extreme care not to allow water or humidity to get into the cylinder - the results will be an early shot blasting with flash rusting/oxidation, worse still lots of flaking rust and the cylinder being condemed, or tragically you kill or mame the filling attendant or yourself if the cylinder explodes under pressure.
 Why have we gone for one of this countries leading edge gas delivery and blending systems ?
We pride ourself with our level and standard of technical diving, training and professionalism. We wanted a system that provided traceability of Gas and clean gas as a standard. We wanted additional levels of safety for us (and hence you), so we designed the system from day one to be safe with 100% Oxygen. Filtered Oil based compressor systems didn't nor couldn't 100% guarantee not to release Oil vapour or other hydrocarbons even with good care and maintenance of the system (filters do not chemically bind with the hydrocarbons and 'seal' them within the inlet side of the filter) so when cool a level of osmotic shunting can occur - equally visual indication of the need to change filters is tricky too.
 We chose Oil Less/Oil Free compressors as the industry standards make clear as this is the least risky with 100% Oxygen use to get specialist mixes of Nitrox, Trimix and all the other mixes we produce. We took a long look at the various filter mediums too and thoroughly tested many key filter cartridges and found after successive tests before we opened, that the best option for our system was to repack our own cartridges and use a leading edge vermiculite that can be found in the commercial diving and nuclear submarine arena, to achieve not only gas to the very high specification of EU and British Standards, but to also ensure the life of the filters was enhanced to work well with the system.
We competitively tendered for the system and RIX in the UK won the contract to supply our system.
Given the industry has come to expect double filtration (tripple just isn't needed as we are an Oil Free/Oil Less compressors and air too dry has physiologically implications), and have ensured these are very big filters to ensure long dwell of the gas through them given the low flow rates from the main compressor. After each filter is a water visual indicator proving we are dispensing air at the legally required quality and standard (from water vapour perspective) and we have found that one tall filter only just meets the tough new standards with our setup (even though we have good water seperators and a good design). We have of course designed the system to be upgraded and we will be buying another compressor later this year.
 The Main Compressor produces gas to 350 Bar, however we run it generally only to 240 Bar and fill three 50L 350 Bar Cylinders - which we call the Interstage Bank - and this provides us with our primary source of air. When the system is left to cool for more than 24 hours we discard the output of the filters back to the atmosphere for the first 500 L to ensure no contaminents are drawn out from the filters. The filters are always kept at a steady 150 to 185 Bar by a back pressure regulator and we deliver this Gas to this Bank via a 5 micron filter (the 7th safety device at this point of the system).
 We then have a main bank of six 50L 350 Bar cylinders that is were we keep our 350 Bar of air stored or put another way a cool 100,000 Litres of air at room temperature. We pump using a second compressor the air from the Interstage Bank to the Main bank - all of which is carefully controlled via the Air Mixing Panel. This flexibility means we can fill cylinders from the Main Bank, from the Interstage Bank or we can pump/Boost the gas from the Main Bank or the Interstage Bank - so even if our bank is low we can still fill 300 Bar cylinders reliably and get good fills.
Sandwiched between these two banks is the nine 50L 350 Bar cylinder bank of our Nitrox and Gas Bank, which is controlled and managed via the Gas Mixing Panel - that's a cool 150,000 Litres of other gas for mixing and blending to get you a very good and accurate mix and a good fill pressure too.
 To ensure further safety each cylinder has a 3 micron filter (thats small enough to block all but the smallest bacteria and viruses !!) to ensure this gas absolutely has no contaminants in it when stored. Again we filter each and every feed with 3 micron filters from each of the Oxygen, Helium and other gases we get to ensure the Gas Suppliers cylinders don't inadvertantly blow in contaminants into our system and your Cylinders too - oh and each of those whips has non-return valves too... As you've guessed we are eliminating any possible fuel that can be made up of any debris... Clever safety features were also designed in to the panel to also stem the possible risks from nearly every perspective. The Gas Cage has three manifolds for three different Gases each with 3 whips and space for a forth. The Photo below is when we were part way through commissioning the system. At the end of the day it is very high pressure and our proceedures for ensuring it is well maintained are as important as it is for you not to contaminate your cylinder or damage its Oxygen Clean status.
 We have gone to these lengths to also offer the Air and Gas so that it is traceable - we know how much air or gas was left in your cylinder, we know its air, oxygen and helium contents before we start filling and also at the end, we know precisely which gas was used to fill the cylinder and from where, its quality and its batch number (for the mixes) - this is why we bar code each and every fill. We do this as our guarantee what we put in it was good and traceable. This does mean if there is a problem we are the only dive facility in the UK, as far as we are aware, that could give the HSE or the Police a list of names and Cylinder serial numbers for Air, Oxygen and other Gas fills to Recall - it also means that we have traceability on each and every scuba cylinder and we have seen them come into new ownership too.
It is with pride that we don't drain cylinders (unless we absolutely have to), for nitrox, oxygen, heliox and trimix we will blend your requirement from the Gas that you have left in your cylinders. You only pay for the Gas that we put in - this makes a huge difference on the amount of money you pay. if we have to drain to achieve a mix - then it will be the minimum amount possible so this is fairly priced and fairly run for you.
 We looked carefully at the design of the system with a view to getting good fills and it became obvious with only a little thought to physics that the non return valves were key to ensuring a rapid rush of gas didn't start heating a very low pressure cylinder then filling it quick. We deliberately chose pipe sizes behind the panel to limit flow rates amongst other things. The 2nd compressor which moves the Air from the Interstage Bank to the Main Bank also pumps the gas with a whole host of safety features (including temperature cut-out which should be an industry standard on all pumps involving Oxygen Boosting - its very supprising how much the gas does heat). I fear for a lot of techies with pumps at home as you will be shocked at the temperatures you will be reaching pumping from a 60 Bar O2 cyklinder boosting to 200 Bar.
We took a very long look at the design such that this two stage approach to achieving 350 Bar Air all the time, by choosing Oil Less/Oil Free, and by using this commercial/military grade filter medium we have produced a system that although it had a high capital outlay, it is very low cost to run and maintain - so we chose to pass this on to each and every customer. We also chose to keep the price per litre reasonably uniform across each cylinder size. We deliberately charge what many see as a unduely low price for the 3L, 5L and 7L cylinders. This was done to encourage safety - a key thread throughout our business. Our view is you often think twice with a couple of quid to refill say a 170 Bar Pony Cylinder, whereas at our price we are actively encouraging people to put safety first and always have a safety reserve of Air/Deco Gas so the cylinder is as full as possible.
The Oxygen, Helium and other Gases that we need to be supplied with were negotiated with a volume order basis and gained very good prices for them and again we make good use of the Nitrox and Gas Bank inside so that we don't hang on to these cylinders for more than 60 days - often in the really bsuy season no more than 18 days! Hence why our Oxygen, Helium and other Gas prices are likewise very competetive and fair - couple that with our Gas fills (Nitrox, Trimix and other blends), being based on not emptying the cylinders were possible - makes our prices some of the best in the country...
Please feel free to Contract Us for more information on this impressive system for your Air and Gas needs...
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