NICET ITWBS Level II cheat sheet

Hydrostatic test pressure for new sprinkler piping: 200 psi (13.8 bar) for 2 hours, or 50 psi above the maximum working pressure when that exceeds 200 psi; no pressure loss is permitted.

Pneumatic (air) testing of sprinkler piping is limited to 40 psi (2.8 bar) unless the piping is specifically approved for higher air pressure; a 24-hour air test with no drop above the allowable leakage is the acceptance criterion.

Flow test for acceptance: measure at the hydraulically most remote inspector's test connection; the flowing pressure and discharge must meet or exceed the design demand (density over area plus hose allowance) at the base of the riser.

Main drain test: record static pressure, then fully open the main drain and record residual pressure; a drop of more than about 10 percent from the previous test indicates a supply or valve problem requiring investigation.

Gauge accuracy: test gauges used for acceptance must be calibrated and read in the range where the needle sits between 25 and 75 percent of full scale; a 0-300 psi gauge is typical for 200 psi tests.

Inspector's test connection must flow the equivalent of one sprinkler (typically 1/2 inch orifice) and be located at the hydraulically most remote point of the system; flow confirms the alarm and verifies no obstructions.

Waterflow alarm test: open the inspector's test connection and verify alarm actuation within 90 seconds for wet systems; vane-type and pressure-switch devices must be retested after any adjustment.

Valve status: all control valves must be open and supervised (locked or electrically supervised); record the valve position and tamper-switch condition at each inspection.

Wet pipe system: verify no low-point drains hold trapped water in areas subject to freezing; check that heat is maintained at 40 degrees F (4 degrees C) minimum in all protected spaces.

Dry pipe system: air pressure must be maintained per design (commonly 20-40 psi) and the dry pipe valve must trip within 60 seconds of the inspector's test connection opening; record trip time and priming water level.

Preaction and deluge systems: test detection circuits independently of the discharge valve, confirm solenoid and releasing panel operation, and verify that the valve opens on detection signal as designed.

Standpipe flow test: verify residual pressure at the topmost outlet; for a Class I system the minimum residual pressure at the highest outlet is 100 psi (6.9 bar) with the required flow.

Fire pump acceptance: run the pump at churn, 100 percent, and 150 percent of rated flow; the pump must produce at least 100 percent of rated pressure at churn and not less than 65 percent at 150 percent flow.

Backflow preventer test: record the pressure differential across the check valves; a reduced-pressure zone assembly must hold the specified differential and the relief valve must open at the design differential.

Obstruction investigation: when the main drain flow is significantly less than expected or the inspector's test flow is weak, perform a flushing or obstruction investigation per NFPA 25 before returning the system to service.

Record keeping: maintain inspection and test records for the retention period required by the applicable standard (commonly one year on site with the current records available to the authority having jurisdiction).