Combined return/suction filters are designed to filter open return loops and provide suction line pressurization for closed loop refill pumps in hydrostatic applications. The use of a 0.5 bar back pressure valve ensures that the refill pump inlet is under positive pressure, thereby minimizing the possibility of cavitation, especially under cold start conditions. There are a number of options available, including suction line safety screens and the possibility of fitting to the side or bottom of the tank with leak-proof protection when servicing the filter element.