BREATHING APPARATUS MAINTENANCE St. Paul, Minn., Fire Department
MAINTANANCE
SCBA enables a fire fighter to get into the seat of the fire and, more importantly, serves as his means of life support in smoke-filled and gaseous environments.
That is why routine maintenance of SCBA is a must to prevent problems at the fire scene.
SCBA maintenance can be divided into two categories: light routine maintenance, which should be performed by all departments, and heavy routine maintenance, which involves more extensive upkeep.
Light maintenance begins with a sight inspection of the mask, checking for scratches and scrapes that can impair vision. Scratched lenses can be buffed with a special buffing wheel and cleaned with manufacturer-recommended solutions. Mask harness straps should be checked and replaced if deteriorated or burned to avoid loss of elasticity and breakage. Bent buckles should be straightened or replaced. The entire facepiece and most SCBA parts can be thoroughly cleaned with a strong, soapy solution in warm water.
Intake valves in the nosecup should be checked for proper position, sealing and obvious signs of wear. Improperly aligned intake valves, in addition to causing inefficient breathing, can negate the antifogging features on some units. The nosecup should be soft, pliable and undamaged.
Exhalation valves should be checked closely and cleaned of debris, because embers often work their way into them. Also, look for signs of wear that can lead to improper sealing.
Remember that some SCBA valves are more accessible than others, and that there are varying degrees of valve mechanism complexity. Most SCBAs have the exhalation valve in the facepiece and can be washed with the facepiece. However, other unit exhalation valves are inside a face-mounted regulator, requiring closer inspection because of their tendency to collect particulates along with the normal accumulation of respiratory moisture. These valves should be serviced as recommended in the unit manual and may require attention under a heavy maintenance program or be returned to the factory for servicing.
Proper valve operation can be verified by checking breathing resistance with a positive pressure test. The spring mechanism in all facepiece regulators creates an air pressure that is measured by a 1 ½-inch column of water. In the event of a leak, the force of the air prevents fire fighters from inhaling hazardous chemicals. A quick positive pressure test is made by putting on the facepiece without tightening the head strap and turning the mask on to positive pressure. Pull the facepiece away from the face and see if there is a steady flow of air. The air flow should stop when the facepiece is resealed. The positive pressure test also serves as a check on the facepiece and the exhalation valve.
Inspecting SCBA regulators for dirt and debris and cleaning them after each use assures clean air delivery. Debris can indicate corrosion within the pneumatic system and warrants further equipment investigation. The newer, simpler regulators can be classified in the light maintenance category, and can be serviced using the procedure and tools recommended by the manufacturer.
However, most units with complex regulators require heavy maintenance and must be serviced by factory authorized service centers equipped with special facilities, tools and personnel.
Most SCBA units have low-pressure hoses that carry air to the wearer. These hoses require regular inspection of the seal at both ends and should be cleaned after every use. It is important to keep the inside diameters of low-pressure hoses moisture free at all times, since moisture can work its way back to regulator parts made of materials that are subject to corrosion. For this reason, it is not advisable to wash them after every use.
Many regulators that reduce air pressure to the mask have small orifices and parts that are susceptible to dust and clogging. Regulators with large, accordion-type, low-pressure hoses should also be checked for deterioration in the folds and for punctures that can severely impair air delivery. Small-diameter stainless steel over high-pressure, Teflon-lined hoses are not subject to deterioration and do not require this check. Screw threads, O-rings and gaskets at each end of the low-pressure hose should also be routinely checked for pitting and wear.
Other parts of SCBA requiring routine maintenance include the pressure status gage that should be checked for proper operation and true readings at various pressures; the SCBA frame that should be checked for cracks and breaks; and the harness that should be checked for frayed stitching and loose rivets.
Air cylinder bottles and gages should be checked for proper air pressure and operation. Heads of air cylinder bottles should be clean and a dust cap kept over the stored bottle head threads to prevent any dirt from clogging the regulator mechanisms. Air bottles should be examined for the date of their hydrostatic test, which is usually recommended every five years for steel cylinders. The aluminum cylinders with fiberglass overwrap require a three-year hydrostatic test.
After use and prior to recharging, all air cylinders should be checked for charring, melting or scarring which may indicate that replacement is necessary. Cuts and gouges should be repaired according to manufacturers’ instructions, usually with resin.
Maintaining SCBA air compressors can also be categorized as light maintenance. The compressor unit should not consume oil, its belts should be checked for wear, and its filters changed regularly. Type 1, grade D breathing air, as described by the compressed Gas Association, is essential for SCBA replenishment.
Fire departments with multiple units may benefit from a heavy SCBA maintenance program, which includes parts inventory, extra units to replace those being serviced, a work area, and service training programs for technicians.
The work bench is central to servicing most SCBA. The typical SCBA work bench requires a continuous air supply for efficient SCBA testing. A high-pressure air bottle is generally insufficient because lower tank pressures can allow some high-pressure SCBA leaks to go undetected. Tests should run at the maximum SCBA pressure rating, usually 2216 psig. Adequate light and organized bench space is also necessary.
A heavy maintenance area demands a dust-free environment for servicing SCBA assemblies that must remain absolutely clean.
The SCBA work area should also have convenient access to hot and cold running water for routine cleaning of SCBA parts, and ample space for organized storage of and convenient access to all necessary tools. Each unit requires a service record to track maintenance scheduling and accommodate manufacturer updates and modifications.
Since avoiding downtime is the big reason for establishing a heavy maintenance program, provisions must be made for having well-stocked inventories of all necessary replacement parts.
Because SCBA are a fire fighter’s life support in hazardous atmospheres, there is no margin for error or carelessness in SCBA maintenance. Therefore, ongoing training programs covering current procedures, techniques and available equipment should be instituted for maintenance technicians.
A departmental SCBA service center can be a valuable resource for current, impartial information on SCBA design, materials of construction, and characteristics that would make some units more desirable than others.
A complete service center should contain a literature reference library of all pertinent manuals, product bulletins, legal, safety and procedural updates. A correspondence file for supplier communications is also recommended.
Since every department may not be able to justify all the equipment or personnel necessary for the suggested maintenance, sharing maintenance facilities or a service center program with other departments might be a solution.
The feasibility of a heavy maintenance program must be weighed against costs incurred for servicing and equipment downtime. The time and expense that a department must dedicate to a SCBA maintenance program depends on its SCBA complexity. Some units require hours of highly-trained personnel time, while others may require less than 30 minutes by a service technician with considerably less training.
If a department decides it is more costeffective to operate its own service program, it will reduce its equipment downtime and gain more control over both the qualify and costs for SCBA maintenance.
