What to do if the fire sprinkler accidentally sprays? 5 common causes of false triggering and preventive measures

1.Common causes of fire sprinkler misfire

Mechanical damage (accounting for 40%)

Typical scenarios:

Ladder hits sprinkler head during renovation

Forklift hits ceiling sprinkler head while carrying goods

Identification features:

Sprinkler head glass tube is broken or metal components are deformed

Preventive measures: Install a protective cover under the sprinkler head, and use concealed sprinkler heads in high-risk areas (such as warehouses)

High temperature misfire (accounting for 25%)

Typical scenarios:

Heat accumulation in kitchen exhaust duct (high temperature sprinkler head is not used)

Electric welding operation does not isolate the sprinkler area

Key data:

Ordinary sprinkler head (68℃) vs high temperature sprinkler head (93℃/141℃)

Preventive measures: Kitchens, boiler rooms and other areas must install high temperature rated sprinkler heads, and cover the surrounding sprinkler heads with fireproof cloth before hot work

Corrosion/aging (accounting for 20%)

Typical scenarios:

Acidic gases in chemical workshops corrode glass tubes

Humid environment causes metal parts to rust

Identification features:

Nozzle leakage, discoloration of glass tubes, metal rust

Preventive measures: Use epoxy-coated nozzles in corrosive environments, and use pH test paper to detect acid and alkali residues on the nozzle surface every quarter

Water hammer effect (accounting for 10%)

Typical scenarios:

Sudden start and stop of water pumps or rapid closing of valves

Pipeline pressure fluctuations exceed the design value (>12bar)

Consequences:

Pipeline vibration causes nozzles to loosen or burst

Preventive measures: Install hydraulic buffers or slow-closing check valves, and use variable frequency control for water pump start and stop (to avoid sudden pressure changes)

Installation errors (accounting for 5%)

Typical errors:

Wrong nozzle direction (should be downward, not sideways or upward)

Use incompatible sealing tape (such as ordinary raw tape)

Specification requirements:

According to NFPA 13 standard, the nozzle thread must be sealed with Teflon tape (thickness ≤ 0.2mm)

Preventive measures: Use a torque wrench to tighten after installation (standard value: 20-30N·m), and entrust a third party to conduct air tightness test (0.5bar pressure for 30 minutes)

2.Emergency handling process after fire sprinkler spraying by mistake

• Immediate action

Close the regional water supply valve (do not touch the main valve of the fire pump!)

Start the drainage system (to avoid the spread of accumulated water)

• Loss control

Cover equipment: Protect precision instruments with waterproof cloth

Document rescue: Prioritize the transfer of paper documents to a dry area

• System recovery

Replace all triggered nozzles (not reusable)

Check the pipeline: eliminate secondary risks caused by water hammer or blockage

• Long-term prevention strategies

3. Fire Sprinkler System Troubleshooting Guide

Common faults and quick diagnosis

• The sprinkler head does not produce water or the water pressure is insufficient

Possible reasons:

Pipeline blockage: sediment and rust deposition lead to water flow restriction.

Valve closed: misoperation or valve failure.

Water pump failure: motor damage or power supply problem.

Insufficient water pressure: municipal water supply pressure fluctuation or pipe network leakage.

Solution:

Check valve status: make sure the main valve and partition valve are fully open.

Test water pressure: use a pressure gauge to detect the pipe network pressure (normal ≥0.5MPa).

Flush the pipeline: remove the end water test device and flush until the water is clear.

• Sprinkler head sprays by mistake (not triggered by fire)

Possible reasons:

Mechanical damage: decoration collision or forklift hits the sprinkler head.

High temperature mis-triggering: high temperature sprinklers are not used in kitchens and boiler rooms (ordinary sprinklers are triggered at 68℃).

Corrosion and aging: acidic environment causes glass tubes to break.

Solution:

Replace sprinkler head: use a new sprinkler head of the same specification (triggered sprinkler heads cannot be reused).

Install protective cover: Install metal protective nets in high-risk areas (such as warehouses).

• System leakage or sprinkler water seepage

Possible reasons:

Seal failure: O-ring aging or loose thread seal.

Pipeline rust and perforation: Long-term humid environment causes metal pipes to rust.

Frozen cracks: Pipes are not emptied in winter, and water freezes and expands and cracks.

Solution:

Replace seals: Use corrosion-resistant fluororubber seals.

Repair pipelines: Epoxy resin to seal leaks or replace rusted pipe sections.

Antifreeze measures: Install electric heating cables or switch to dry systems in cold areas.

• The water pump cannot start

Possible reasons:

Power failure: power failure, fuse blown.

Control cabinet failure: relay damage or PLC program error.

Mechanical jam: impeller is stuck by foreign objects or bearing damage.

Solution:

Check the power supply: Use a multimeter to test the voltage (380V±10%).

Manual cranking: Disconnect the power supply and manually turn the pump shaft to confirm flexibility.

Key component testing methods

Sprinkler function test

Tools: Sprinkler test pliers (avoid direct heating or impact).

Standard: The temperature of the glass tube color code must match the environment.

Pipeline network pressure test

Steps:

Close the main valve and connect the pressure test pump.

Pressure to 1.5 times the working pressure (such as 1.2MPa), maintain the pressure for 30 minutes, and the pressure drop is ≤0.01MPa to pass.

Alarm valve group detection

Key inspection:

Whether the hydraulic alarm rings (water flow rate ≥1m/s during the test).

Whether the pressure switch signal can link the fire pump.