Clean in-place (CIP) is a process that uses a cleaning solution, which is circulated through a piping network for a period of time. The solution is then drained and replaced with a fresh solution and the process repeated until the piping is clean. Steam–in–place (SIP) is similar, in that it involves the use of a cleaning solution and a piping network. The main difference is that SIP relies on high temperatures from steam to kill microorganisms and sterilize the pipes, valves and other elements of process systems.