In closed loop hydrostatic transmission systems, it is often necessary to bleed off some of the oil from the circuit and replace it with cool, clean oil from a charge replenishing pump. The hot oil is typically routed through a filter and cooler before returning to the reservoir. System designers use a hot oil shuttle valve to achieve this. Higher pressure fluid from the loop causes the shuttle valve to shift allowing oil from the low pressure side of the loop to be ported out the common port. These valves are usually used in conjunction with a relief valve. Parker’s K04F3 has an open center position with metering orifices to control flow. Capable of 15 gpm and up to 6000 psi, the K04F3 valve is available with 5 switching pressures.