Valve By-pass Complete BAP37 Series

The bypass valve is used together with piston pumps if the pump turns constantly when the vehicle is on (in installations with the power takeoff without a coupling or coupled directly to the motor). In such cases, all the oil flow delivered is circulated, at the maximum pump capacity permitted by the turning speed of the motor, through piping that is usually not sized for capacities greater than those required for the normal use of the pump, consequently giving rise to pointless energy losses and overheating in the system. The bypass valve serves the purpose of partially recirculating the pump’s oil flow Q (see diagram 1) inside the pump so that a fl ow Q1 (corresponding to the difference between the total flow Q and the recycled fl ow Q2) circulates through the system’s piping. The proportion of total capacity distributed to the flows Q1 and Q2 depends on the system load losses and the bypass valve. In any case, it is essential to guarantee an oil flow Q1 of at least 5-10 l/min to ensure adequate pump cooling.