Every fire protection system is taken out of service many times over its life: an extension, a leak repair, pump maintenance, tank cleaning. Being out of service is not the problem; failing to manage it is. The picture that recurs in post-fire investigations is a valve shut for work that stayed shut without anyone knowing. This article turns impairment management into a procedure that works on site.
What is an impairment, and why does it need its own procedure?
An impairment is any condition in which a fire protection system, or part of one, cannot work as designed: a closed control valve, a pump switched to manual or out of order, a drained tank, an isolated alarm circuit. NFPA 25 sets out a process for these conditions built around a responsible person (the impairment coordinator), a tag system, and steps for notification, interim measures and restoration. FM Global's Red Tag practice follows the same logic: an impairment starts with a written permit, is tracked on that permit and is closed out with a test.
A separate procedure is needed because the decision to impair a system is usually taken by the maintenance team, while the consequences fall on operations, security, the insurer and the fire service. The procedure makes sure all of them know at the same time.
Planned and emergency impairments
| Aspect | Planned | Emergency (unplanned) |
|---|---|---|
| Examples | System extension, valve replacement, tank maintenance, pump overhaul | Pipe burst, pump failure, freezing, accidental damage |
| Preparation | In advance: scope, duration, materials and crew are planned | None: water is shut off first, then the procedure starts |
| Notification | In writing, before work starts | As soon as it is discovered, by the fastest route; written record completed afterwards |
| Extent | The smallest possible section is chosen | Isolation to the smallest section is attempted first |
| Goal | Restore the system as quickly as possible | Safe isolation and the fastest possible repair |
Step-by-step site procedure
1. Appoint a responsible person
Every site should appoint an impairment coordinator and a deputy in writing. No valve, pump or alarm circuit is taken out of service without the coordinator's permission. Everyone, contractors included, needs to know this rule.
2. Keep the extent to a minimum
Close only the affected zone valve rather than the main valve. Break the work into stages and restore the system at the end of each stage within the same shift. Materials and crew should be on site before the valve is closed. Never take the pump and the tank out of service at the same time; one should stay in service while the other is maintained.
3. Tag it
Hang an impairment tag on the closed valve, the fire pump controller and the fire service inlet. The tag states what is out of service, which areas are affected, the start time, the expected finish, and the responsible person with their phone number. A firefighter or security officer arriving on site should understand the situation at a glance.
4. Notify
The notification list is prepared in advance and usually covers:
- Those responsible for the affected areas and the shift supervisors.
- Site security and the alarm receiving centre (otherwise the supervisory signal gets silenced as a fault).
- The insurer or broker; your policy may make this a condition.
- The local fire service and the authority having jurisdiction where required.
5. Put interim measures in place
- Fire watch: a trained person with a means of communication patrols the affected area at regular intervals, knows how to raise the alarm and where the extinguishers are.
- No hot work: welding, cutting and grinding stop in the affected area. For the permit system see hot work permit system (NFPA 51B).
- Reduce hazardous operations: flammable liquid transfers, high-risk processes and deliveries of new stock are postponed where possible.
- Extra firefighting equipment: more portable extinguishers and hose reels, and a temporary water supply if one can be arranged.
- Long impairments: NFPA 25 requires one of a set of measures, such as evacuation, an approved fire watch, a temporary water supply or reducing the hazard, when a system is out of service for an extended period within a day (more than 10 hours in the current edition). Confirm the threshold against the edition in force and with the authority having jurisdiction.
6. Do the work and track progress
The coordinator follows whether the work is on schedule. If it will overrun, notifications are renewed. An impairment that will stay open overnight may need different measures from one planned for daytime.
7. Restore and test
Restoration does not end with opening the valve. As a minimum:
- Open the valve fully; check stem position on OS&Y valves and the indicator on butterfly valves.
- Lock the valve open, or confirm at the panel that the tamper switch reports normal.
- Carry out a main drain test and compare static and residual pressures with previous results. A marked drop points to a valve that is closed or only partly open.
- If a pump was impaired, return it to automatic and carry out a run test.
- Confirm alarm and supervisory signals reach the receiving centre.
- Remove the tags and tell everyone on the notification list the system is back in service.
- Close and file the permit.
The most common mistake: skipping the main drain test on the assumption that the valve "was opened". The only way to know a valve is not partly shut is to watch the pressure drop under flow. Typical closed-valve patterns are covered in closed valve failures.
Impairment permit: minimum fields
| Field | Content |
|---|---|
| Identity | Permit number, requester, approving coordinator |
| Extent | Equipment impaired, areas affected, planned/emergency |
| Duration | Start, expected finish, actual finish |
| Notifications | Parties informed, time and person |
| Measures | Fire watch, hot work ban, extra extinguishers, temporary water |
| Restoration | Valve position, main drain readings, signal test, pump status |
| Close-out | Tags removed, final notification, signature |
After a fire, this form is the strongest evidence that the system was taken out of service deliberately and under control; its importance from an insurance point of view is covered in why fire insurance claims get denied. Impairments become frequent during building work; for the particular risks of that period see fire risk during refurbishment, and for the wider ITM framework the inspection, testing and maintenance guide.
Frequently Asked Questions
When should the insurer be told about a planned impairment?
Before work starts and within any notice period set by your policy. Many insurers require advance notice of planned impairments; confirm your own policy conditions with your broker.
Who can act as a fire watch?
A trained person who knows the area, knows how to raise the alarm and where the extinguishers are, has a means of communication and is not tied up with other work. The scope and frequency of the watch may be set by the authority having jurisdiction or the insurer.
Why carry out a main drain test after reopening a valve?
Because a valve's full opening is confirmed by pressure under flow, not by eye. A result markedly lower than previous readings points to a partly open valve or even a blockage.
What comes first in an emergency such as a burst pipe?
Shut off the water at the nearest valve feeding the affected zone and limit the damage. Then the procedure starts: tag, notify, fire watch and hot work ban. The aim is to impair only the smallest necessary part of the system for the shortest possible time.
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Download MEP Calc on the App StoreNFPA 25 (current edition), impairments chapter · FM Global DS 2-81 and Red Tag practice · NFPA 51B. Confirm duration thresholds and notification requirements against the edition in force, the authority having jurisdiction and your insurer. The findings here are typical defect patterns, not an account of events at any particular site.