If not properly set up and maintained, compressor rooms and fill stations can be among the most hazardous areas of a dive business. Determine how safe your compressors and fill stations really are by conducting a dedicated risk assessment of your facility. A single high-level walk-through of the rooms that house your compressors and associated equipment can clue you in to a variety of hazards that you can address — before they cause a devastating accident.
(Before you begin your assessment, download the DAN Hazard Identification & Risk Assessment Guide. This comprehensive guide is available to you at no cost and provides detailed explanations of the most common risks dive businesses face. The section dedicated to compressor and fill-station operations begins on Page 70, and we recommend prioritizing the following items.)
Compressor Room
There are quite a few safety considerations to keep in mind when assessing a compressor. Contamination can come from many different sources, including exhaust from a nearby boat or parking lot, smoke from cigarettes or cooking, cleaning products and other volatile chemicals and generators. To prevent air contamination, be sure your compressor’s air intake is positioned far away from potential sources of contamination. Consider posting a sign near the air intake prohibiting running motors, smoking, etc. nearby. Better yet, install a physical barrier or move the intake so that it is out of reach of any of these sources of harm
In addition to taking steps to prevent contamination, use logs and checklists on the compressor to track and ensure essential functions and reliability. In addition to logging information about each fill, log the date and type of service performed on the compressor, the reason for the service, actions taken, parts replaced, the name of the technician and the date of the next planned service.
Fill Station
Most dive shops have unique fill station configurations that reflect their business and customer demands. This means that there is no single correct way to set up your fill station; rather, there are guidelines that must be followed. The most important of these is probably that your fill station be inaccessible to anyone but trained employees. Fill stations are potentially dangerous spaces in which hazardous work takes place; they are not suitable for high traffic or social gatherings.
Once you’ve ensured restricted access to your fill station, make sure you have set fill procedures that all employees are required to follow. These procedures may address inspection of customers’ cylinders prior to filling, safe fill rates, coupling and uncoupling, cylinder thread types, knowledge of maximum pressure ratings for cylinders, oxygen analysis and record keeping. Create separate procedures for each type of mixed gas your operation offers.
High-Pressure Hoses
High-pressure hoses used to fill cylinders can be dangerous given the right circumstances, so these should be assessed on a regular basis. Hoses should be as short as practically possible; the longer the hose, the greater risk of damage caused by a loose fill whip in the event of a failure. Wherever possible, consider using rigid piping to reduce the length of flexible hoses.
All high-pressure hoses should be fitted with whip restraints to prevent any hose from whipping if it becomes separated from its end-fitting. These can cause serious and even fatal accidents. Assess the condition of all flexible hoses on a regular schedule and consider replacing hoses that are used on a daily basis every five years.
High-Pressure Hose Assessment
| Length | Material | Hose Ends | Condition |
| High-pressure (HP) hoses should be kept as short as practicable | The material should be appropriate for the application, the maximum allowable system pressure and the expected operating conditions | Hose ends should be made of suitable products that are corrosion-resistant, rated to at least the maximum allowable system pressure and appropriate for the gas that will be used | The condition of all hoses should be assessed periodically, as hoses can deteriorate due to exposure, rough handling, poor-quality materials, age, abrasions, etc. |
| Rigid piping should be considered to reduce the length of flexible hoses | The material’s kink- and abrasion-resistant properties should be maximized | Certain hose ends (e.g., clamped, barbed fittings) should not be used in HP applications | Hoses and hose ends should undergo regular (at least annual) visual inspections and leak-checks, and the results should be logged |
| The use of flexible hoses longer than 6.5 feet (2 meters) should be considered carefully (such hoses should be subject to stringent visual inspections and maintenance regimens; they should also include anti-whip characteristics and should be specifically designed for use in extensive, unsupported lengths) | Swivel ends should be considered if stress due to twisting is likely | As a general rule, flexible hoses used for HP gas transfer should be replaced every five years | |
| Consider installing longer HP hoses within suitable protective conduits or pipes to limit the potential for damage in case of a hose failure | Hose-end connections should be fitted with whip-restraint devices designed to reduce whipping action in case hose ends fail or hoses are not properly vented while being connected or disconnected |
Emergency Action Plans
In addition to covering your response to dive accidents, your emergency action plans (EAPs) should also address problems that arise in the fill station or compressor room. If you don’t already have EAPs for your fill station or compressor room, draft them. Effective EAPs for these areas should include, at a minimum, procedures for responding to contaminated breathing gas, high-pressure component rupture (fill whip, cylinder, etc.), fire and injury. Compile or review your EAPs and consider doing high-level walkthroughs or simulations for each potential emergency
As you conduct your risk assessment, bear in mind that not all risks carry the same weight. Prioritize areas in which exposure is regular and the consequences of an accident would be significant. Remember, even a cursory inspection of rooms that house bank and cascade systems, chemicals or spare parts can alert you of numerous potential hazards. Taking just a few hours to assess these areas and use what you observe to refine the safety of your operation can prevent serious accidents.