Abstract: A method for cleaning piping including the steps of supplying an acid to a cleaning water to prepare a cleaning water having pH of 4 or lower, mixing ozone gas to the cleaning water, and passing the cleaning water through the piping to be cleaned, or a cleaning system for piping, the system including a reservoir which retains cleaning water, an acid providing means supplies an acid to the cleaning water, an ozone generation means which generates ozone gas, a circulation flow path including a circulation pump which connects the reservoir and the ozone generation means in the form of a closed circuit, and circulates the cleaning water between the reservoir and ozone generation means, a conduction flow path including a conveying pump which communicates the reservoir and the piping to be cleaned, and conveys the cleaning water retained in the reservoir through the piping to be cleaned.

Abstract: A method for cleaning piping including the steps of supplying an acid to a cleaning water to prepare a cleaning water having pH of 4 or lower, mixing ozone gas to the cleaning water, and passing the cleaning water through the piping to be cleaned, or a cleaning system for piping, the system including a reservoir which retains cleaning water, an acid providing means supplies an acid to the cleaning water, an ozone generation means which generates ozone gas, a circulation flow path including a circulation pump which connects the reservoir and the ozone generation means in the form of a closed circuit, and circulates the cleaning water between the reservoir and ozone generation means, a conduction flow path including a conveying pump which communicates the reservoir and the piping to be cleaned, and conveys the cleaning water retained in the reservoir through the piping to be cleaned.