Approximately 21 years of PLTGU Perak-Grati operational. Within this period the circulating water pipes have increased head losses. The increase can be caused by changes in the roughness of pipes, the deposition of foreign materials in pipes, and other factors. Head losses cause the water supply to the condenser does not meet the top tubes in the condenser causing the amount of condensable vapor to water to decrease requiring additional water supply from make up water tanks. As a result of these things is the cost of production increases. The purpose of this study is to analyze the increase of head losses by comparing the initial design data of PLTGU Perak Grati in 1997 with actual data at present. The results of the calculation will be able to provide recommendations related to the performance of circulating water pump and maintenance strategy in order to improve the performance of the generating industry in PLTGU Perak-Grati. The research method used with the Darcy-Weisbach Equation. Assumes the Circulating Water Pump condition is the same as the initial condition. The result of comparison at the beginning of design and actual show increase of head losses due to the corrosion rate in the pipe causing friction in the pipe to increase. Head losses are called major and minor losses, or major losses major and minor losses, head losses major due to friction losses in pipes and minor head losses due to losses in the turns , reducer, valve and so on. The increase of head loss of pipeline from intake sea water to condenser inlet is 0.841 m. where the head loss at the beginning of the design of 0.666 m to actual current 1.507 m by coating rubber and cleaning on the pipe can reduce head loss by 0.686 m