Brandt SB4000, Operator'S Manual

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Closed Center (Load Sensing - Flow Compensating) - HM4C
Many tractors are being introduced with load sensing systems (also referred to as flow and pressure compensated
systems) which simplify system setup and eliminate many of the problems associated with using the wrong size
pump motors on a given hydraulic system.. Usually, any of Hypro’s 9300HMC models may be used on this type
of system, provided the hydraulic system produces sufficient oil flow for the hydraulic motor being used (Refer to
the Pump Selection Guide).
This system maintains a constant flow of hydraulic oil for a given pressure drop. The
flow is adjustable with a flow control valve installed in the hydraulic system (such as the
Tortoise/Hare control on John Deere tractors). Because this system has adjustable
flow, there is no need to bypass hydraulic oil as in an open center system, or to restrict
the flow with orifices as in a closed center pressure compensated system.
Adjusting Centrifugal Pump Output
1. Make sure the orifice from the pressure port adapter of the hydraulic motor has been removed (HM4C model
only).
2. Close and lock down the bypass adjusting screw in the hydraulic motor.
3. Set the tractor hydraulic flow control valve for minimum hydraulic oil flow to the remote outlet (Tortoise
position).
4. Start the tractor and allow the hydraulic oil to circulate for approximately 10 to 15 minutes or until adequately
warmed.
5. Prime the centrifugal pump by opening the upper stop cock in the pump until a steady strem of water flows out.
6. Engage the hydraulic lever to start the pump.
7. Slowly adjust the tractor hydraulic flow control valve until the until the pressure on the pump guage is just
below 120 psi.
8. Open the agitation line valve until sufficient agitation is observed.
9. Fully close the Electric Regulating Valve.
10. Turn on the Spray Pipe Ball Valves. Adjust the Throttling Valve to have 30 psi more pressure at the spary tips
than will be used when spraying in the field.
Flow Control