The C30HDZ concrete pump has one main pumping piston which is valved by means of two ball checks. (A inlet, and B outlet.)

The secondary piston is used as a compensator piston to smooth out the pulsations of a single piston action.Note:The compensator will not start operating until material is pumped into the line and back pressure develops.

The compensator spring, which is installed on the compensator piston rod, deflects with each piston stroke.This“spring cushion”, in conjunction with the cam profile, produces and uninterrupted smooth flow of material under average pumping conditions.

The pumping cylinder (Figure 10) retracts drawing the material past the ball (A) and filling the cylinder.The compensator piston is pumping the material out to the nozzle and causing ball (B) to seat preventing the material from returning to the pumping cylinder intake.

HOW IT WORKS

An automatic, centrifugal clutch is installed to engage and disengage the pumping action without stopping or starting the engine.The centrifugal clutch is set at 1100 R.P.M.The engine idle speed is approximately 875 R.P.M.; therefore, the clutch is completely disengaged at idle.The throttle settings while pumping should always maintain an engine R.P.M.high enough to prevent the clutch from slipping and burning the clutch lining.

The return spring which is installed on the rocker arm, is installed to eliminate shock and stress between the cam roller and the cam weldment when the pump is in operation. If the return spring is removed or replaced for any reason, maintain the backing plate dimension of 3” as shown on Figure 3, to produce the proper pre-loading of the spring for a smooth performance.

Figure 10. Pumping Cylinder

MAYCO C30HDZ PUMP — OPERATION AND PARTS MANUAL — REV. #12 (04/03/12) — PAGE 27

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Multiquip C30HDZ manual HOW IT Works, Pumping Cylinder