Emergency Oxygen units

By Robert N. Rossier


Proper care and maintenance is vital to ensure yours is ready for action.

Nobody likes bad news, but sometimes a diving tragedy serves as an important reminder. A fatal dive accident on a liveaboard in the Maldives in 2008 was just such a case. The accident involved carbon monoxide contamination of breathing gas, which caused the death of one diver and injured nine others. Among the disheartening details from the news reports: The shipboard emergency oxygen system was broken, and thus oxygen could not be provided to the victims.

In a diving emergency, oxygen first aid can save lives (See "First Aid Refresher"), but only if the emergency kit is fully charged and in good operating condition. Proper maintenance is vital, especially in tropical environments.

Maintenance Concerns
Emergency oxygen systems do not require an inordinate amount of maintenance, but they do require periodic attention. The problem becomes one of "out of sight, out of mind." Most emergency oxygen systems aren't used regularly, and over time components made of plastic, rubber and other synthetic materials can deteriorate and become brittle. Oxygen systems should be professionally serviced at least every two years, more often if they are used heavily. (For a list of approved service centers, visit DAN Training and Education: Oxygen Fill Stations.)




Beyond periodic professional maintenance, the best practice to ensure the readiness of an emergency oxygen system is to remove the unit from the boat after each trip and completely inspect it. For commercial operators, DAN® recommends a bimonthly check of shipboard emergency oxygen systems.

First, inventory all parts, and make sure all components are available. "Once, on a DAN video shoot for a training program, we asked to borrow an oxygen cylinder from the boat's supply because we ran out and needed just a bit more," says Eric Douglas, director of DAN Training. "It took the crew half an hour to find all the parts to the oxygen unit on board because they had been stowed in various places."

When all parts are accounted for, make sure the components are in good condition and ready for use. Look for these common problems:

Uncharged or empty cylinders — Before heading out on a dive or dive trip, ensure that the oxygen cylinder is full. To be filled, oxygen cylinders must also be hydro-tested every five years, so check the hydrostatic test date as part of the bimonthly inspection.

Corroded regulators and components — Perhaps the single biggest environmental concern regarding oxygen systems is corrosion of the metal parts. The locker of a dive boat represents a harsh environment with plenty of heat, humidity and corrosive salts. "Even the slightest amount of salt air that gets trapped inside a case and then sealed up begins to corrode the equipment," Douglas says. "We've opened up units stored on dive boats that are so rusted and corroded you would be afraid to turn them on for fear they would explode."

To protect an oxygen system from corrosion, store it in a watertight case with a silica gel packet to absorb any moisture trapped inside.

Damaged regulator and control valve assembly — The regulator/control valve is really the heart of the emergency oxygen system, and it must also be kept clean, dry and free from physical damage. Bob Eberly, president of EMS Technologies in Leola, Pa., said one potential problem with the cylinder/regulator assembly is physical damage to the pressure gauge. Mishandling, dropping or improperly stowing the emergency oxygen system can sometimes result in a damaged gauge that may not provide a reliable pressure reading. If physical damage to the pressure gauge or the regulator assembly itself is noted, have the unit repaired.

Damaged or deformed cylinder-regulator seals — Another potential problem with an emergency oxygen system involves the seal between the oxygen cylinder and the regulator assembly. A Public Health Notification updated by the U.S. Food and Drug Administration and the National Institute for Occupational Safety and Health in 2006 revealed that faulty or improper sealshave resulted in at least a dozen regulator fires. At issue were the two different types of seals commonly used in emergency oxygen systems; they have decidedly different characteristics.

One type of seal is a crushable plastic or nylon device designed for a single use. When the regulator is tightened to the cylinder, the material deforms to create a good seal, but the deformation is permanent. If these seals are reused, they require additional torque to ensure a good seal. If they start to leak, the friction caused by the flow of oxygen across the face of the seal can cause ignition.

Many manufacturers recommend a different type of seal, referred to as a "sealing washer," that is designed for multiple uses. These consist of metallic rings encompassing an elastometric element made of a flexible polymer. These are generally more expensive than the crushable seal, but they can be safely reused many times without the need for additional torque to ensure a proper seal. All DAN oxygen units come equipped with this type of "oxygen washer."

Deteriorated delivery masks — Heat and exposure to the elements can result in deterioration and cracking of rubber and synthetic components. "We often see old masks left to harden and turn brown in cases," Douglas says. "Non-rebreather masks are designed for single-patient use and should be kept in their protective bag until they are needed. We often see an old mask wadded up inside the case that was used for training at some point, and that is the only mask available for use in an emergency."
Oxygen System Basics
Emergency oxygen systems come in various sizes and styles, but most incorporate the same basic elements: a high-pressure oxygen storage cylinder, a regulator/control valve assembly and a delivery mask.

The two primary types of emergency oxygen systems for divers are constant-flow systems and demand systems. Constant-flow systems provide a regulated, and in some cases adjustable, flow of oxygen to the delivery mask. Demand systems provide oxygen in response to the user's inhalation, thus delivering a higher percentage of oxygen and wasting less gas. Because treatment needs can vary from case to case, DAN recommends a multi-function system that can provide oxygen using both the demand and constant-flow options.


© Alert Diver — Winter 2010

Categories

 2019
 2018
 2016
After anaesthesia Air Quality Air exchange centre Air hose failure Altitude changes Altitude sickness Ama divers Anaerobic Metabolism Annual renewal Apnea Apnoea Arterial gas embolism Arthroscopic surgery Aurel hygiene BCD Badages Bag valve mask Bandaids Barbell back squat Bench press Blood flow Bouyancy compensators Boyle's Law Boyle\'s Law Bradycardia Brain Breast Cancer Breath Hold Diving Breath hold Breath-hold Breathing Gas Breathing Bruising Buoyancy Burnshield CGASA CMAS CO2 Cabin pressure Camera settings Cancer Remission Cancer treatments Cancer Cannabis and diving Cannabis Cape Town Dive Festival Carbon dioxide Cardio health Cardiomyopathy Chamber Safety Charles' Law Charles\' Law Charles\\\' Law Charles\\\\\\\' Law Charles\\\\\\\\\\\\\\\' Law Chemotherapy Cleaning products Coastalexcursion Cold Water Cold care Cold Compressed gas Conservation Contaminants Contaminated air Corals Courtactions Crohns disease Crystal build up Crystallizing hoses Cutaneous decompression DAN Courses DAN Profile DAN Researchers DAN medics DAN report DCI DCS Decompressions sickness DCS DM training DReams Dalton's Law Dalton\'s Law Dalton\\\'s Law Dalton\\\\\\\'s Law Dalton\\\\\\\\\\\\\\\'s Law Deco dives Decompression Illness Decompression Sickness Decompression illsnes Decompression treatment Decompression Diaphragms Diseases Dive Chamber Dive Industry Dive Instruction Dive Instructor Dive Pros Dive Research Dive Training Dive accidents Dive buddies Dive computers Dive gear Dive health Dive medicines Dive medicine Dive safety Dive staff Diveleader training Diveleaders Diver Profile Divers Alert Diving Kids Diving career Diving emergencies Diving guidelines Diving injuries Diving suspended Diving Domestic Donation Dr Rob Schneider Drysuit diving Drysuit valves Drysuits EAPs EAP Ear pressure Ear wax Ears injuries Education Emergency action planning Emergency decompression Emergency plans Emergency underwater Oxygen Recompression Emergency Enviromental Protection Environmental factors Environmental impact Environmental managment Equipment care Evacuation Exercise Extended divetime Extinguisher Extreme treatments Eye injuries FAQ Failures Fatigue Faulty equipment Fire Coral Fire Safety Firefighting First Aid Equipment First Aid Training First Aid kits Fish Fitness Flying Francois Burman Free diving Free flow Freedive Training Freediver Freediving performance Gas Density Gas laws Gas mixes GasPerformance Gases Gastric bypass Gear Servicing Gordon Hiles HELP HIRA Haemorhoid treatment Hazard Description Hazardous Marine life Health practitioner Heart Health Heart Helium High temperatures Hot Humans Hydrate Hydrogen Hydroids Hydrostatic pressure Hyperbaric Chamber Hyperbaric research Hypothermia Immine systems In Water Recompression Indemnity form Indian Ocean Inert gas Infections Instinct Instructors Insurance Integrated Physiology International travel International Irritation Kidneys Kids scubadiver Labour laws Legal advice Legislation Leukemis Liability Risks Liability releases Liability Life expectancy Lifestyle Low blood pressure Low pressure deterioration Low volume masks Lung function Lung injuries Lung MOD Maintenance Mammalian Dive Response Mammalian effect Master scuba diver Maximum operating depth Medical Q Medical questionaire Medical statement Middle ear pressure Mike Bartick Military front press Mixed Gas Mono Fins Mooring lines More pressure Muscle pain Mycobacterium marinum Nautilus Nitrogen build up Nitrox No-decompression Non-rebreather Mask Normal Air Nosebleeds O2 providers O2 servicing OOxygen maintenance Ocean pollution Orbital implants Oronasal mask Oxygen Cylinder Oxygen Units Oxygen deficit Oxygen deicit Oxygen ears Oxygen equipment Oxygen masks Oxygen supply Oxygen therapy Oxygen P J Prinsloo PFI PJP Tech Part 3 Photography Pistons Planning Plastic Pneumothorax Pollution Pool Diving Preparation Prepared diver Press Release Professional rights Provider course Pulmanologist Pulmonary Bleb Purge RAID South Africa RCAP Radio communications Rashes Recompression chamber Recompression Recycle Regulator failure Regulators Regulator Remote areas Renewable Report incidents Rescue training Resume diving Risk Assessments Risk assesments Risk elements Risk management SABS 019 Safety Stop Safety Saturation Diving Save our seas Science Scuba Air Quality Scuba Injury Scuba children Scuba dive Scuba health Scubalearners Sealife Skin Bends Skin outbreak Skin rash Snorkeling Snorkels Sodwana Bay Splits Squeezes Standars Supplemental oxygen Surgeries Surgery Tattoes Technical Diving The Bends The truth Thermal Notions Tides Tips and trick Transplants Travel tips Travel Tweezers Unconsciousness Underwater photographer Underwater pho Vaccines Vagus nerve Valsalva manoeuvers Vape Vaping Vasvagal Syncope Venting Volatile fuels Washout treatments Wastewater Water Weakness Wetsuit fitting White balance Winter Woman in diving Work of Breathing Wound dressings Wreck dive Wreckdiving Youth diver abrasion air-cushioned alert diver altitude anemia antibiotics antiseptics bandages bent-over barbell rows body art breathing air calories burn cardiovascular checklist chemo port child clearances closed circuit scuba currents cuts dead lift decompression algorithms decongestants dehydration dive injuries dive medicing dive ready child dive reflex dive tribe diver rescue diver training dive diving attraction doctors domestic travel dri-suits dry mucous membranes dry suits dry e-cigarettes ear spaces elearning electrolyte imbalance electroytes emergency action plans emergency assessment equalizing exposure injuries eyes fEMAL DIVERS fire rescue flexible tubing frediving gas bubble health hospital humidity immersion pulmonary edema (IPE join DAN knee longevity lower stress marine pathogens medical issues medical procedures medical risk assesment mental challenge minor illness mucous membranes nasal steroids nasal nematocysts newdivers nitrogen bubbles off-gassed operating theatre operations orthopeadic outgas pain perforation phillippines physical challenges pinched nerves plasters polyester-TPU polyether-TPU post dive preserve prevention rebreather mask rebreathers retinal detachment risk areas safety stops saturation scissors scuba equipment scuba single use sinus infections smoking snorkeling. spearfishing stings strength sub-aquatic swimmers ears tattoo care tecnical diver thermal protection training trimix unified standards vision impaired warmers water quality