Fire Suppression System Impairments
Industrial fire suppression systems include automatic sprinklers, gaseous systems as well as foam systems that might be used in aircraft hangars or to protect certain flammable liquid operations.
Associated with the above systems are control/water supply equipment such as fire pumps, water storage tanks, control valves, alarm systems, smoke/heat detectors and underground fire service mains (both public and plant owned). If any of this equipment is taken out of service, it can impair the ability of the fire suppression system to operate properly and thus, allow a potential fire to grow uncontrolled and result in not only building and contents damage but also possible interruption to production.
Impairments are classified into two major categories, those being planned and emergency.
Examples of a planned impairment would be:
- Sprinkler modifications requiring the closing of a sprinkler control
valve.
- Draining a water storage tank for internal or external servicing.
- Trip testing and cleaning a dry pipe valve.
- Servicing a diesel fire pump (oil change, coolant flush).
A planned impairment can be scheduled during plant shutdown or when hazardous operations are off-line. This greatly reduces the potential for a fire.
Examples of an emergency impairment would be:
- Leak in a control valve, sprinkler head or sprinkler piping.
- Underground leak (public main or plant lead-in).
- Fire pump not operating properly.
With respect to ceiling sprinkler systems specifically, impairment procedures would only apply if five or more heads are taken out of service.
Measures During the Impairment
Regardless of the type of impairment, the precautionary measures taken during the impairment are similar. An impairment coordinator should be designated and ensure the following are addressed: