Why do Goldacres use diaphragm pumps and not centrifugal pumps?

Diaphragm pumps are constant displacement pumps providing a consistent flow, largely unaffected by changes to operating pressure. Diaphragm pumps have good suction capacity and can easily self prime, they can also run dry without damage. On Goldacres sprayers we supply the operator with the pump RPM and therefore the operator can be confident of the flow rate of the pump and confident the agitation to sprayer tank is consistent, even when quite large changes to operating pressures are made.

Centrifugal pumps: It is not possible to be certain of the pump flow by monitoring pump speed and the limited suction capacity of a centrifugal pump adds a further area of uncertainty to pump output. Centrifugal pumps flow rate varies considerably with pressure changes.

Maintenance: It is sometimes claimed centrifugal sprayer pumps require less maintenance than diaphragm pumps. At Goldacres we have not found this to be the case. Cast iron pumps are subject to chemical erosion. Centrifugal pumps which are run dry even for short periods can be severely damaged.