The purpose of this procedure is to define the step by step method to implement the correct practices for the precommissioning & commissioning of “Fire Fighting System” through the guidelines contained herein so as to ensure that the job execution complies with the project requirements and serves the intended function to satisfactory level.
Pre Commissioning Procedure for Fire Fighting System
Ensure that the system installation is complete and mechanical completion is approved.
Ensure that no damage has occurred between mechanical completion & precommissioning.
Repair all damages to the equipment & piping.
Check that the Fire Fighting piping network is complete with fire hose reel, cabinet, pressure gauge, fire extinguishers proper valves, drains vents strainers pressure switches instruments & sprinklers drains, vents, strainers, switches, in place as per final approved shop drawing.
Ensure that the Fire Fighting network is hydraulically pressure tested and approved.
Make sure that the entire system is cleaned internally & externally.
Ensure that the Fire Fighting pumps are precommissioned & commissioned as per approved procedure.
Make sure that all the pressure switches are installed & wired properly.
Ensure that all supervisory isolation valves & sectional control assembly valves are installed & wired.
Make sure that all drain valves & vents are installed.
Ensure that the identification of all valves & pipework is complete.
Make sure that the wiring to the Fire Alarm from the firefighting pump panel is complete.
Ensure that the BMS connections are complete.
Check and ensure that the wiring diagram of pump set controls & schematic piping drawings are displayed near or inside the pump panel.
Commissioning Procedure for Fire Fighting System
Ensure that all the precommissioning checks are carried out successfully.
The fire fighting system shall be completely tested for proper sequence of operation as defined below.
System Description
The Fire fighting system comprises of 3 pumps (2 main & 1 standby) single suction, horizontal multi stage, multi outlet pumps & 2 vertical multi-stage type jockey pumps (one for low zone and other for high zone) to supply firewater to sprinkler and fire hose systems.
All the pumps have dedicated control panel & pressure switches.
The sprinkler system in the tower building is divided into two zones, low zone and high zone.
Low zone includes Car park and Ground floor to 15th floor of Towers & the High
zone includes 16th floor to roof of Towers.
The Wet riser piping, which supplies firewater to all hose reels and hose racks, is classified as high zone for the complete project with PRV for all cabinets.
The precommissioning & commissioning of Hose racks & Hose reels shall be in line with the approved procedure
Pumps Sequence of Operation
High Zone – 16th floor to Roof
System pressure will be maintained always at 16 bar. In the event of water consumption in the fire protection system high zone areas due to any reasons, the pressure in the high zone system piping will fall down.
When the pressure reaches 15 bar, Pressure Switch HZPS4 will cut in and the high zone Jockey pump will start. If pressure in the system piping reaches to the cut out pressure of HZPS4 (16 bar), then the high zone Jockey pump will stop.
While the high zone Jockey pump is in operation, if the pressure drops further to cut in pressure of HZPS1 (14 bar), then Main Fire fighting pump will start and jockey pump will stop.
Main firefighting pump will continue to run till the pressure reaches the cut out pressure of HZPS1 (16 bar).
While the Main Fire Fighting pump is in operation and if the pressure drops further to cut in pressure of HZPS2 (13.00 bar), then other firefighting main pump will start and both the main pumps will run.
Main Fire Fighting pumps will continue to run till the pressure reaches the cut out pressure of HZPS1 and HZPS2 (16 bar).
While both the Main Fire Fighting pumps are in operation and due to any reasons any one of the main pump fails to work, if the pressure drops further to cut in pressure of HZPS3 (12.50 bar), then the Standby Fire Fighting pump will start and both the Main Fire Fighting pump and Standby Fire Fighting pump will continue to run till the pressure reaches the cut out pressure 16 bar.
Low Zone – Ground Floor, carpark to 15th floor
System pressure will be maintained always at 10 bar. In the event of water consumption in the fire protection system low zone areas due to any reasons, the pressure in the low zone system piping will fall down.
When the pressure reaches 9.00 bar, Pr. Switch LZPS4 will cut in and the low zone Jockey pump will start.
If pressure in the system piping reaches to the cut out pressure of LZPS4 (10 bar), then the low zone Jockey pump will stop.
While the low zone Jockey pump is in operation, if the pressure drops further to cut in pressure of LZPS1 (8.00 bar), then main fire fighting pump will start and jockey pump will stop. Main Fire Fighting pump will continue to run till the pressure reaches the cut out pressure of LZPS1 (10.0 bar).
While the Main Fire Fighting pump is in operation and if the pressure drops further to cut in pressure of LZPS2 (7.00 bar), then Main Fire Fighting pump will start and both the main pumps
will run. Main Fire Fighting pumps will continue to run till the pressure reaches the cut out pressure of LZPS1 and LZPS2 (10.0 bar).
While both the Main Fire Fighting pumps are in operation and due to any reasons any one of the main pump fails to work, if the pressure drops further to cut in pressure of LZPS3 (6.50 bar), then the Standby Fire Fighting pump will start and both the Main Fire Fighting pump and Standby Fire Fighting pump will continue to run till the pressure reaches the cut out pressure 10.0 bar.
Demonstration procedure
High Zone
The water in the system shall be allowed to drain vide the high zone Alarm Control Valve. This will reduce the pressure in the system & the jockey pump will start.
More water shall be allowed to drain to further drop the pressure, then the Duty pump will start, the jockey pump will stop.
Upon confirming the start of the main pump, the discharge valve shall be throttled & the pump will not be able to cater to the pressure drop in the system & the other duty pump will start.
Discharge of the pump will also be throttled, which will initiate the starting of the stand-by pump.
The start & stop of the pumps shall be as per the pressure settings.
Low Zone
The low zone shall be tested in the same way as high zone, but by using the Alarm Control Valve for the low zone.
Sprinkler System Demonstration
The sprinkler system will be tested using the Sectional Control Assembly.
Test & drain valve shall be opened in each zone and the following shall be verified.
Flow switch will activate & give signal to Fire Alarm System.
Fire Alarm System will induce an audible alarm.
Jockey pump will start automatically.
SIGNALS TO BMS PANEL
- Pump running status.
- Pump trip status.
ATTACHMENTS
- Pre-commissioning check sheet for Fire Fighting System
- Commissioning check sheet for Fire Fighting System
- Risk Assessment