Abstract: Standard volume pipe used for flow meter's calibration shall be calibrated every three years by metering calibration department. Cleaning of the volume pipe shall be made before recalibration to remove greases in the standard section of the pipe and wax deposited in pipe wall. If thorough cleaning is not given, standard volume and accuracy of the volume pipe shall be affected. By summarizing the experience in-volume pipe's cleaning and maintenance, puts forward a new cleaning method and process to ensure true, accurate and reliable calibrating result. The method is also applicable for volume pipe of other type.