An 8-Hour Shutdown in an Occupied Hospital Wing
The sprinkler system in an occupied six-story hospital wing has a 6 in. riser and 95 psi static pressure. A renovation requires draining and cutting a 3 in. branch main to relocate 14 sprinklers and add 6 in a patient-care suite. The contractor schedules an 8-hour shutdown starting at 7:00 a.m. Tuesday: close the control valve, make the cut, refill, hydrostatically test at 200 psi for 2 hours using the building's own water supply, then sign the material and test certificate. The alarm company is not scheduled, the AHJ has not been notified, and the suite remains occupied throughout. The contractor says a fire watch is unnecessary because the work area was already issued a hot work permit for the soldering.
1. What must be in place before the control valve is closed?
Read the worked answer
- AHJ and facility notification in writing. An 8-hour shutdown in an occupied health care wing is an impairment, and the NFPA 25 impairment procedure applies: notify the authority and the building owner/occupant, tag the closed valve, and record the time out of service.
- Fire watch or approved mitigation for the affected area for the duration. The suite is occupied, so 'we are only cutting one main' does not remove the risk; coordinate with the facility's life safety plan.
- The alarm company scheduled to place the affected zones in test or bypass and to restore and verify afterward. An untested zone is an open item at closeout.
- Hot work permit and area preparation for the soldering - necessary, but it is not a substitute for the impairment plan, and the permit does not cover the sprinkler outage.
- A written restoration and verification plan (refill, vent, confirm pressure, reopen the valve, confirm alarms) with a named responsible person and a time.
Judgement: a certificate signed at 3 p.m. implies the job ended when the last joint was soldered. Restoration, alarm verification, and notifying the AHJ that the system is back in service are part of the same day's work and must be scheduled, not assumed.
2. Evaluate the proposed hydrostatic test and the sequence around it.
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The pressure is right; the pressure source is not. With a normal working pressure of 95 psi (below 150 psi), the 200 psi / 2-hour test governs. The building's own supply sits at 95 psi static and cannot reach 200 psi. A temporary test pump with a calibrated gauge at the low point is required, arranged so test pressure cannot back up into the city main.
Sequencing issues:
- Flush before connecting. Cutting a 3 in. main and adding pipe invites debris; flush the new piping to a drain before tying in and before the hydrostatic test, so scale does not end up in the branch lines and the flow switch.
- Isolate what cannot take 200 psi. Backflow devices, pressure-reducing valves, and any component with a lower rating must be isolated or removed and tested separately per the manufacturer.
- Leave joints accessible if the AHJ intends to witness the test; a test after concealment is of limited value.
- Record it: start and end pressure, time, gauge identification and calibration date, and a description of any leakage. A small drop from trapped air is not the same as a leak.
- After the test: flow switch and alarm test, then restoration and the return-to-service record.
3. List the closeout documentation this scope requires, and explain why each item is not optional.
Read the worked answer
- Contractor's Material and Test Certificate for the modified system, signed by the installing contractor, showing the hydrostatic test pressure and duration, the flow test, and the AHJ witness.
- Gauge calibration records for the instruments used in the test.
- Alarm and supervisory test results for the affected zones - flow switch, valve tamper - with the alarm company's restoration signature.
- Closed impairment record: time out of service, time returned, notifications to the AHJ and the facility, and fire watch hours if used.
- Record drawings showing the relocated and added heads and the new main routing.
- Updated ITM schedule for the facility, since the zone layout and device addresses changed.
Why each matters: a perfect 200 psi test that cannot be tied to a calibration record, a witnessed date, or a closed impairment is a finding at the next inspection. The technical work and the documentation are one deliverable, and the exam-style judgement is recognizing that the paperwork is part of the installation, not an afterthought.