NITROX PRODUCTION WITHIN A DIVE OPERATION Presented by: Cesare Benelli,Coltri Sub & Glenn Huebner, Nuvair

WHAT IS “NITROX”? N2O2 Also referred to as EAN, EaNX, Enriched air, & Enriched air nitrox A gas mixture containing nitrogen & oxygen with a higher % of oxygen than normal breathing air OEA - Oxygen enriched air

WHY DO RECREATIONAL DIVERS USE NITROX? Less N2 absorption in body tissue. Lessens risk of decompression sickness. Provides longer bottom times. Increases safety margins. Popular with Dive masters & instructors.

WHEN CAN RECREATIONAL DIVERS USE NITROX? On all recreational dives. Leading training agencies have introduced optional nitrox training within entry level courses. Leading training agencies have also introduced introductory programs to initiate divers to nitrox prior qualification

WHAT % OF REC DIVERS ARE USING NITROX? Exact figures not known, but tens of 1000’s of divers train each year with Nitrox Many dive resorts & liveaboard/charter vessels are already providing nitrox

TRAINING REQUIRED FOR THE USE OF NITROX Courses are available from all major DSAT agencies Basic Nitrox training allows diving with up to 40% mix Technical Nitrox training is required for mixes over 40%

WHY OFFER NITROX ? To increases potential revenue Provides more & diverse diving opportunities for clients. Provides additional training opportunities & revenue Attracts more customers to your dive centre / vessel Extra equipment sales

ADDITIONAL REASONS TO OFFER NITROX. Reduction of DCS exposure to divers on multi-day dive trips Reduces operator, Dive master & Instructor liability Provides a marketing edge over competitors. Adoption of Nitrox by all major training agencies Emergence of ‘tech’ diving within the mainstream.

WHO ELSE USES NITROX? Recreational dive professionals Public safety divers Scientific divers Commercial divers NASA astronauts

HOW IS NITROX DELIVERED TO THE DIVER? Specially marked cylinders Diver must have proof of nitrox certification Diver must analyze gas Diver must sign gas log For ‘Nitrox Experience’ programs Certified DM/Instructors to comply with above procedures.

NITROX PRODUCTION OPTIONS: PARTIAL PRESSURE BLENDING CONTINUOUS FLOW BLENDING MEMBRANE SYSTEM

PARTIAL PRESSURE BLENDING Decant 100% pure O2 to dive cylinder ** 2. Top off with O2 J grade compatible air ** ** Amounts vary according to required mix and cylinder contents & must be calculated.

ADVANTAGES OF PARTIAL PRESSURE BLENDING Lowest start up costs of blending methods. Popular with technical divers

DISADVANTAGES OF PARTIAL PRESSURE BLENDING Requires transport and handling of 100% pure high pressure O2 Requires error free mathematical calculations Requires special filtration & expensive consumables to reach J grade quality air. Requires trained/certified gas blending technician.

ADDITIONAL DISADVANTAGES OF P/P BLENDING Mix may not be exact +/- P/P blending should be very slow 100% O2 availability Purchase & transport costs of 100% O2 High levels of liability for operators

CONTINUOUS FLOW BLENDING Gas is pre-mixed using O2 & breathing air with a blending panel 2. Normal high pressure compressor is used to fill cylinder

ADVANTAGES OF CONTINUOUS FLOW BLENDING Relatively inexpensive More practical & faster than partial pressure blending If using an automated blending panel its is an easy to use & precise method. The panel achieves reduction of associated O2 handing risks with the use of auto O2 cut - off valves

DISADVANTAGES OF CONTINUOUS FLOW BLENDING 100% O2 availability Purchase & transport costs of 100% O2 High levels of liability for operators

MEMBRANE SYSTEM NITROX PRODUCTION Normal Air filtered to Grade E standard & pumped into membrane @ low pressure O2 permeates thru membrane more than N2 . N2 rich mix vented, O2 rich mix pumped into high pressure compressor ** Normal high pressure compressor used to fill cylinder. ** N2O2 mix controlled via air flow rate into membrane.

POSSIBLE MEMBRANE SYSTEMS LP compressor - LP filtration - Membrane - HP compressor - cylinder

POSSIBLE MEMBRANE SYSTEMS Air bank - LP pressure reducer - LP filtration - Membrane - HP compressor - Cylinder

ADVANTAGES OF A MEMBRANE SYSTEM Simple operation No need to store or mix high-pressure O2 Virtually eliminates hazards associated with handling 100% O2 Highly accurate method of blending

ADDITIONAL ADVANTAGES OF MEMBRANE SYSTEMS FAST: Fill nitrox tanks at same speed you fill with air LOW: Maintenance & operating costs. SIMPLE: Training & use. Note: Membrane systems have the lowest levels of Operator risk exposure when filling Nitrox cylinders.

RELIABILITY OF THE COLTRI /NUVAIR MEMBRANE Systems reliable as a normal air compressor systems 20-30 year life span Compressor are covered by 1 year warranty Membrane systems are covered by 5 year warranty. Note: It is Important stated maintenance procedures are followed

DISADVANTAGES OF A MEMBRANE SYSTEM? Higher initial capital investment May require additional electrical power

IS A NEW HP COMPRESSOR NEEDED FOR NITROX? Can usually use your existing compressor . A well maintained ‘used’ compressor may need a mild overhaul and internal cleanup if previously used with mineral oil.** ** Any HP Compressor used to compress Nitrox must be lubricated by a synthetic oil rated for use with nitrox

IS USING NITROX WITH A HP COMPRESSOR SAFE? There are attendant risks with compressing any gas Compressing N2O2 containing 40% or less O2 poses no more risk than pumping normal breathing air at higher pressures

WHEN USING MEMBRANE OR CONTINUOUS BLENDING… Considerations: Slightly more conservative than compressing air Compressor oil Compressor operating temp. Filtration

WHAT IF I NEED TO PRODUCE 40%+ NITROX MIX? Recreational Divers will not use more than 40% Nitrox The most popular mix currently used within dive centers/vessels is 32% If a deco mix exceeding 40% is required by tech divers a P/P system can be used. Note: Recommended depth limit for recreational divers is 30m, best suited to a 32% Nitrox mix

TRAINING STAFF TO FILL NITROX TANKS Most people can learn to operate a membrane nitrox system in less than one hour. We will be conducting a live demonstration at the end of this session

END OF PART ONE