Abstract: A proportional flow divider valve is configured only as a controlled flow valve by using a first spool in a valve body or as both a free flow valve as well as control flow valve by using a second spool in the valve body. The second spool is provided with a return fluid check valve which is integral therewith and disables the control flow mode when pressure is applied to a piston surface on the return flow check valve. The return flow check valve is configured as a split sleeve which fits around a lateral inlet passage through the second spool and is urged to close the lateral inlet passage under pressure from returning hydraulic fluid. Normally, the split sleeve is axially biased by a vented coil spring to open the lateral inlet passage in the spool.

Abstract: A three-way valve is configured as a solenoid operated diverter when the solenoid is used in parallel with a poppet valve. When the diverter is in a first mode, hydraulic fluid entering a first port exits the valve through a system outlet port while hydraulic fluid entering a second port exits through a second port. The solenoid valve is positioned to close the second port when energized in order to shift the system to a second mode. When the solenoid valve is energized to close the second port so that all of the fluid entering the second port opens the poppet valve and exits through the system outlet. By utilizing a poppet valve in parallel with a solenoid valve rather than a valve spool, the three-way diverter is able to operate at higher pressures and higher fluid flow because Bernoulli effects which cause closing of valve spools used in prior art three-way valves do not adversely affect the poppet valve.

Abstract: Needle valves which are seated in valve seats defined by circular edges have DELRIN.RTM. tips for the purpose of minimizing unseating torque which would otherwise be excessive due to the thermal expansion and contraction characteristics of the valve seats and the needle valves. In salt spreaders with aluminum valve seats and steel needle valves, the needle valves become stuck in the valve seats if the needle valves are seated after operation in frigid weather and the salt spreaders are subsequently garaged to raise the temperature of the valve seat and needle valves. By utilizing the DELRIN.RTM. tips, the needle valves do not become stuck.