|  | Public Health Safety | Work Safety

OSHA Hydrostatic Testing & Extinguisher Hazards

Fire extinguishers are pressurized cylinders containing an extinguishing agent that is specially designed to extinguish a specific type of fire. Extinguishers have their contents pressurized to a level that will allow for a fire to be extinguished in a matter of seconds, but only if the extinguisher itself is properly maintained. Many states require fire protection specialists to inspect extinguishers on a regular basis. According to the State of Minnesota Department of Health, fire extinguisher maintenance is required annually and hydrostatic testing is required every six years,

  1. Periodic inspection and maintenance

    • Periodic inspection and maintenance of fire extinguishers is the most basic of steps taken to ensure the extinguisher is in proper working order and is accessible for use. According to the University of Colorado department of Facilities Maintenance, extinguishers must be maintained in an accessible area without obstruction, with operating instructions and nameplate of the extinguisher facing outward. Additionally, the extinguisher must be checked monthly for proper operating pressure by examining the gauge, fullness by lifting the extinguisher, and corrosion or physical damage of the extinguisher, extinguisher hose, and nozzle.

    Annual and Six Year Maintenance

    • Annual inspection of fire extinguishers must be done by a competent professional. The state of Minnesota department of health requires, as many states do, that an approved fire extinguisher servicing company perform annual inspection and maintenance. This list can be obtained from a state fire marshal. Annual maintenance must include a thorough examination of mechanical parts, extinguishing agent, and expelling means. Six year maintenance involves hydrostatic testing which is a method for determining the soundness of the extinguisher cylinder itself and is performed in a controlled environment by an approved servicing company.

    Hydrostatic Test Procedures

    • In order to perform a hydrostatic test, the extinguisher is emptied and a thorough visual inspection is conducted. This includes an examination of the weld seams, and an internal examination of the cylinder. The hydrostatic testing procedures at Hydrolab, a company specializing in hydrostatic testing of pressure vessels, is mirrored by companies throughout the country. After passing visual inspection, cylinders are filled with water and a special valve filled with water is placed at the top of the cylinder. Once all the appropriate seals are made, the cylinder with the special valve is placed inside a test chamber filled with water. Pressure is then applied to the water inside the cylinder being tested. Special instruments called burettes are used to measure the expansion of the cylinder. If the cylinder expands too much, it indicates that the cylinder failed the hydrostatic test. Pressure is then released from the cylinder and the cylinder is measured again. If the cylinder does not return to its near normal size, it means that the cylinder again has failed the hydrostatic test and must be discarded.

    Extinguisher Safety Concerns

    • Hydrostatic testing is performed on cylinders to ensure that the cylinders are strong enough to safely contain a pressurized extinguishing agent. Pressure fluctuations on the extinguisher gauge may indicate that the cylinder capacity has been compromised and the extinguisher is no longer suitable for use, according to Fire-extinguisher101.com, a website dedicated to the safe use and maintenance of fire extinguishers. Compromised extinguishers could burst upon use or may not have the pressure required to adequately expel the extinguishing agent in the event of a fire.

Work Safety - Related Articles