Patent ID: 8377222

Claim:
A method for cleaning an interior surface of a processing equipment using a treatment liquid, the processing equipment including a pipe section defining pipe section first and second ends, the pipe section defining a pipe section volume delimited by the pipe section first and second ends, the pipe section being initially at an initial internal pressure, said method comprising: introducing a coherent predetermined volume of the treatment liquid into the pipe section at a location substantially adjacent the pipe section first end, the predetermined volume of the treatment liquid filling only part of the pipe section, the predetermined volume being substantially smaller than the pipe section volume; and moving the predetermined volume of the treatment liquid through the pipe section by reducing an internal pressure within the pipe section at a location substantially adjacent the pipe section second end to a level substantially below the initial internal pressure, and simultaneously increasing an internal pressure within the pipe section at a location substantially adjacent the pipe section first end to a level substantially above the initial internal pressure; wherein simultaneously reducing and increasing said internal pressure respectively substantially adjacent the pipe section second and first ends moves the predetermined volume of liquid in the pipe section.