There are four aspects in the maintenance safety measurements for circulating water pump:
1.turn off the control power of the water pump maintained, and hang the sign on the power switch, which is written that under maintenance and prohibit to switch on.   
2.turn off the water inlet valve and outlet valve of the water pump maintained, and hang the sign on the valves, which is written that under maintenance and prohibit to operate. 
3.put temporary barriers near the working place, and hang the sign written the sentence of under maintenance.
4.analyse the possible dangerous aspects caused by maintenance before starting it and prepare the corresponding precontrol measures, and tell the dangerous aspects and precontrol measures to the workers.