Aug 2009

Fire Suppression System Impairments

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:

1. The building Fire Brigade or security personnel should be notified and placed on alert. In addition, the central station alarm company should be notified to as to the systems out of service to avoid a false alarm during repairs.

2. All sprinkler control valves that are shut should be tagged for easy identification.

3. All Hot Work (welding, grinding) and hazardous production operations should be discontinued.

4. A continuous fire watch should be established with the designated person instructed as to whom to contact if a fire is noticed.

5. An attempt should be made to limit the area affected by the impairment. Note the following examples:

* If there is an underground fire loop around the building, specific divisional valves can be closed to isolate the impaired area and leave the remainder of the plant in service.

* If only a section of in-rack sprinklers or ceiling sprinklers are impaired, it may be possible to disconnect the damaged piping from the main system, cap the pipe on the main system and put it back in service.

6. The public fire department should be notified. Depending upon the occupancy hazard of a specific location, the fire department may dispatch personnel to tour the area affected to better prepare their fire fighting staff. In some cases, they may assist with the provision of a fire watch.

7. If possible, the ceiling sprinkler system in the impaired area (assuming it is not part of the impairment) may be able to be charged from an adjacent active fire service water line. If this is not possible, an attempt should be made to provide a charged fire hose in the affected area.

8. All necessary repair equipment should be on-hand to aid in making repairs in a timely manner.

9. The “Risk Logic Fire Protection Impairment Tag” should be used (see attached sample). It addresses the above precautions as well as provides contact information.

10. If Risk Logic is servicing your account, we should be notified before and after the impairment. We will follow up with the impairment coordinator on major impairments or those of a long duration

Restoring Systems to Service

When all impaired equipment is restored to normal working order, the impairment coordinator should verify the following:

1. All sprinkler control valves that were closed have been fully re-opened.

2. All central station and local fire alarms have been restored and the alarm monitoring company has been made aware that the alarm system is active and not in a test mode.

3. The Fire Brigade, all plant personnel and the fire department should be notified that all protection has been restored.

4. Any necessary inspections and tests should be conducted to verify all systems are operational. This could include 2 in. drain tests, flows of Inspectors Test Connections, hydrant tests or fire pump tests.

5. The Impairment Tag should be closed out and kept on file.

Controlled Impairment

This type of impairment references testing of fire protection equipment. There is no need to use the above referenced impairment procedure during the following events:

1. Taking alarms off-line to test the Inspectors Test Connections or 2 in. drains.

2. Closing plant discharge valves to test a fire pump.

3. Performing “turn down tests” of non-indicating sprinkler control valves.


An impairment to fire suppression equipment is inevitable. Properly handled, the risk of an uncontrolled fire can be greatly reduced.

Impaired fire suppression equipment is one of the major causes of property losses in industry. Keeping down time to a minimum and properly handling the impairment will greatly reduce the chance of a fire loss.

Risk Logic can provide detailed information with respect to the proper method of handling an impairment.