Method of preventing damage to a pump

A multiphase pump comprising:

• a housing comprising a flow inlet and a flow outlet which are fluidly connected to each other via a flow path;
• a rotor arranged in the flow path of the housing, the rotor being configured to propel a fluid from the flow inlet to the flow outlet via the flow path, the rotor comprising a longitudinal axis which extends for a length of the rotor and a multiphase impeller arrangement;
• at least one leak path which is configured to permit a reverse flow of the fluid from the flow outlet to the flow inlet;
• and
• at least one channel which is arranged within the housing, the at least one channel being configured to direct a liquid from a liquid source to one of the at least one leak path in the multiphase pump.