ZD 900 – 600 OPEN FRAME With electric motor

After many years of close cooperation, the Belgian Clasal took over the piston pump section from Geho ZD from WEIR Minerals Netherlands BV. With this lies design, production and distribution of the original ZD pumps in the hands of Clasal.

The GEHO ZD series is a twin-cylinder quadruple-acting crankshaft-driven piston pump. The GEHO design is purpose build contractor proven and is extremely suitable for wellpoint dewatering by gravity or vacuum and for horizontal dewatering (drainage).


    Water, air or water and air mixtures are primed and discharged 4 times per crankshaft revolution. Two crankshaft driven pistons are arranged in a Vee at 90°, so that the four piston strokes for each revolution follow in regular succession. The crank timing produces a moderate pulsating type action in the dewatering line that prevents clogging of the wellpoint strainers and achieves priming from greater depths.

    • Constant water and air flow, independent of suction and discharge head
    • Self-priming with a suction lift (vacuum) of 9.6 mWK without the aid of an separate power absorbing vacuum pump
    • Permanent high efficiency minimizing energy consumption
    • About twice as efficient as a conventional vacuum priming impeller pump
    • Robust design for ease of transportation and handling
    • Rapid and economical maintenance and low spare parts usage
    • economical and longer carefree service life reducing overall project costs
    • Unprecedented high availability allowing continuous and unattended operation
    • accessibility for ease of inspection and maintenance which require no special skills
    • Resistant to brackish water
    • Permit universal application. Depending on soil conditions, up to 100 wellpoints and up to 300 metres of header pipe can be connected to a single pump
    • Can run dry without causing damage to the pump

    Pump specifications


    ZD 900

    ZD 600


    with gear casing

    with gear casing

    Max Capacity

    95 m³/h

    65 m³/h

    Max Discharge head

    20 m H2O

    20m H2O

    Max Suction head

    9.6m H2O

    9.6m H2O

    Connecting parts



    Weight (empty)

    Ca. 900 kg

    Ca. 900 kg

    Electric motor

    5,5 kW

    5,5 kW



    Tough, compact construction with integral single helical precision gears


    Self-contained oil splash lubrication

    Piston discs

    Wear resistant high molecular polyethylene


    Stainless steel, easy replaceable

    Piston rod

    abrasion and corrosion resistant hard surface piston rods

    Valve seats

    Bronze, saltwater resistant

    Valve system

    Rubber discs with stainless steel guides

    Gearbox, pump body

    Alloyed cast iron

    Inspection covers

    Covers at the side of the pump body for cleaning

    Cross head

    Attached to the connecting rod with sleeve bearings


    Antifriction type drive shaft and crankshaft bearings


    Clasal controls the complete line of production

    • Full control over the entire production line
    • More than 100 years of experience as manufacturer of piston pumps
    • Every pump is extensively tested
    • Use of wear-resistant and durable materials
    • Own foundry which is ISO 9001 certificated

    Why a ZD pump from Clasal?

    • Compact and light, yet large in capacity, efficiency and service life
    • Original GEHO spare parts
    • The sides and top can be opened 180° degrees, which makes all parts easily accessible for maintenance

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