Our definition of maintenance free refers to the fact that the HYDRASEP has no internal moving parts or filters that must be serviced on a periodic basis. In most applications equipped with a GN series controller, we recommend a monthly inspection of the control unit only, and an annual visual inspection of the separator. This annual inspection requires the removal of three mainway hatches and observation of the liquids within these sections. The annual inspection should take 30 to 60 minutes, depending on the type and location of the installation.