The CF15 pump from Varna includes a self-contained pressure bypass valve to prevent motor overload, and a low-pressure-loss check valve to prevent backflow. The pump provides constant pressure, which is particularly valuable in pre-lube applications to prevent backflow from the main engine lube pump. The CF15 pump delivers a 56 L/min flow with AC, DC or compressed air motors. The whisper vane design provides low noise pumping as well as low maintenance through the direct coupling of the pump heads to the motors.