That WIP-13-1 fuel pump is commonly used by r/c boaters using a clutched gasoline engine to supply water to the cooling cap, exhaust manifold and pipe connections while the boat is stopped or going slow.One line comes from a water pickup to the pump,another to the cooling cap and the third is a pulse line to the engine crankcase or intake.Once the boat reaches a certain speed the pump doesn't pump and the pressure in the line takes over.On the boat below I have it running to the cooling cap then to a Y with one line to the water cooled header and one out the side of the boat.