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Rebuilt Dry Claw Vacuum Pumps

Dry claw vacuum pumps 100% rebuilt, restored to original equipment manufacturers specifications.

Edwards Drystar QDP40 Dry Vacuum Pump Rebuilt Refurbished

Edwards Drystar QDP40 Dry Vacuum Pump Rebuilt Refurbished
    Item Number: EDWARDS-DRYSTAR-QDP40

    Warranty: 1 year past the documented date of installation.

    *Product images are for reference purposes only and do not necessarily correspond to the actual product.  

    Please call for price and availability

    IN STOCK - Please call for price and availability 855-466-6822

    Edwards Drystar QDP40 Dry Vacuum Pump Rebuilt Refurbished

    QDP Overview

    The QDP pumps operate at pressures between atmospheric and ultimate vacuum with no lubricating or sealing fluid in the pumping chamber. This ensures a clean pumping system without back-migration of oil into the system being evacuated.

    QDP pumps have enclosed, water-cooled motors and are therefore suitable for applications in clean environments where fan cooling is unacceptable.

    The QDP Pump

    The QDP pumps are each fitted with a gas system, exhaust-silencer and check-valve. The pump is fixed to the framework by vibration isolators. The framework has castors and levelling feet.

    The QDP pumps are four-stage, positive displacement rotary pumps in which pairs of intermeshing rotors (of different profiles mounted on common shafts) are held in correct phase relation by a pair of timing-gears. The timing-gears and the adjacent double-row angular contact ball-bearings, are oil lubricated.

    The pump shafts and rotors are made from cast-iron. The internal and external shaft-seals on the motor drive-shaft are made of polytetrafluoroethylene (PTFE). Bearings are located on the high vacuum end of the shaft, near to the pump-inlet. These bearings are packed with perfluoropolyether (PFPE) grease.

    Gas System

    QDP pumps have a gas system of stainless steel pipelines (see Figure 1) which allows nitrogen to be delivered to the following points :

    • Inlet-purge
    • Shaft-seal purge
    • 2/3-interstage purge
    • Exhaust-purge
    • 3/4-interstage purge.

    You will connect your nitrogen supplies to this gas system through connectors on the gas services panel

    Temperature control system

    The low vacuum stage of the pump has an indirect cooling system, all other stages are air-cooled by natural convection and radiation. In the secondary circuit of the indirect cooling system, coolant circulates around the pump-body by natural convection. In the primary circuit, cooling-water is circulated through copper coils to extract heat from the coolant. In operation, the pump is maintained at a constant temperature by a thermostatic control-valve (TCV) which controls the supply of cooling-water to the primary circuit in the pump.

    The pump-motor is cooled by water flowing through a cooling jacket which surrounds the motor. The pump-motor cooling circuit is separate from the pump cooling circuit. The cooling-water supply and return pipelines are connected to the pump by connectors on the water services panel at one end of the pump

    The cooling-water manifold on the pump distributes the cooling-water to the pump cooling circuit and to the pump-motor cooling circuit (and to the QMB pump-motor cooling circuit, if a QMB pump is fitted). When a QMB pump is not fitted, the flow of cooling-water to the QDP pump-motor is greater than the minimum required flow. When a QMB pump is fitted, the cooling-water flow is distributed equally between the two pump-motors and the overall flow requirement for the pumping combination increases

    Two thermal snap-switches are fitted to the pump-body. One of these snap-switches (the warning switch) opens at 88 oC and the other snap-switch (the shut-down switch) opens at 95 oC. Use the warning switch to provide a warning that the pump is too hot. Use the shut-down switch to shut down the pump.

    Three motor-protection thermistors are fitted to the pump-motor (one on each winding). These thermistors are solid-state devices which have an electrical resistance of 100 to 500 W at normal pump-motor operational temperature. When the pump-motor is too hot, the electrical resistance rises quickly to 3000 W. The thermistors are connected in series and you can use the output of the thermistors to shut down the pump because the motor is too hot.

    Electrical system

    The QDP pumps have universal voltage and frequency motors. These motors are supplied configured for ‘low voltage’ operation (200-208 V at 50 Hz or 200-230 V at 60 Hz).

    You will connect your electrical supply cable to the pump through a cable-gland on the terminal-box on the end of the pump-motor (see Figure 10). You must use a suitably rated contactor (see Section 2.4). The electrical services panel has a connector to connect the outputs of the thermal snap-switches and the motor-protection thermistors to your control equipment.

    Exhaust system

    The pump outlet is connected to an exhaust-silencer, which is below the pump. The outlet also has a port which allows gearbox vent gases to join the main exhaust stream (see Figure 1). The exhaust-silencer attenuates the pulses in the exhaust pressure and reduces pump-induced resonance in your exhaust-extraction system. The outlet of the silencer has a check-valve which prevents the suck-back of exhaust vapors after the pump is shut down. The valve also provides additional attenuation of the pulses in the exhaust pressure.


    A number of accessories are available for the QDP pump; use these to configure the pumps for specific applications.

    QDP40 General Specifications
    Mass 172 kg
    Motor rating 2.2 kW
    Warm-up time to nominal performance 15 min
    Inlet connections ISO40
    Outlet connections NW40
    Vacuum system maximum leak-rate

    1 x 10-5
    (1 x 10-3
    Exhaust system maximum leak-rate

    1 x 10-5
    (1 x 10-3
    Ambient operating temperature range 5 to 40 °C
    Maximum ambient operating humidity 90% RH
    Protection degree (as defined by IEC 529) IP44
    Continuous A-weighted sound pressure level (at 1 meter) < 70 dB(A)
    Performance data

    Typical peak pumping speed

    44 m3h-1
    55 m3h-1
    Displacement (swept volume)

    52 m3h-1
    62.4 m3h-1
    Typical ultimate vacuum
    without gas-ballast



    5 x 10-2 mbar
    (5 x 100 Pa)
    3 x 10-2 mbar
    (3 x 100 Pa)
    Electrical Supply
    Supply Voltage

    Voltage tolerance

    200-208/380-415 V at 50 Hz, 3-phase
    200-230/460 V at 60 Hz, 3-phase
    ±10% (except for 208 V and 415 V at 50 Hz= which are +6% and -10%)
    Cooling Water
    Maximum supply pressure
    Minimum required pressure differential
    across supply and return
    Typical heat removed from pump
    Maximum water consumption
    Maximum particle size in supply

    100 psi (6.9 bar absolute, 6.9 x 105 Pa)

    30 psi (2.1 x 105 Pa)
    1.75 kW
    See Table Below
    0.03 mm2
    Nitrogen supply
    Supply pressures and flow rates
    Fittings type

    For recommendations, see Table 2
    1/4 inch compression
    Table 1: Maximum cooling-water consumption
    Pump Operating Temperature
    (at thermal snap-switch position)
    Maximum water consumption at ultimate vacuum with 50 Hz electrical supply, cooling-water supply temperature of 20 oC and a pressure differential across the supply and return of 30 psi (2.1 x 105 Pa)
    55 °C
    70 °C
    90 °C
    300 lh-1
    150 lh-1
    135 lh-1
    * The 88° thermal snap-switch must be configured to provide warning only,
    or you must fit the high temperature thermal snap-switch kit:
    Table 2 - Recommended nitrogen supply pressures and flow rates
      Shaft-seals purge 3/4-interstage purge 2/3-interstage purge Inlet purge Exhaust purge

    Supply pressure (min)

    8 psig
    (1.55 x 105 Pa)
    - - - -
    Supply pressure (max) 10 psig
    (1.69 x 105 Pa)
    - - - -
    Flow Rate (1.min-1) 25 (max) 20 (max) 5 (max) 25 (max) 5 (typical)
    Full load current ratings
    Supply voltage and frequency

    200-208 V
    200-208 V
    230 V
    60 Hz
    380-415 V
    460 V
    60 Hz
    Full Load (A)
    Rating (kW)
    Temperature control system
    Water Cooling System
    Coolant capacity

    Indirect water-to-coolant heat exchanger
    1.7 litres
    Thermostatic control-valve
    Working temperature range
    Maximum sensor temperature

    AVTA DN15
    50 to 90 °C
    130 °C
    Thermal snap-switches
    Opening temperatures

    Closing temperatures

    Contact rating
    Maximum voltage
    Maximum current (inductive load)
    Maximum current (resistive load)

    Fenwal Inc
    88 °C (warning switch)
    95 °C (shut-down switch)
    78 °C (warning switch)
    85 °C (shut-down switch)

    240 V
    6.3 A
    12 A
    Motor-protection thermistors
    Reference temperature
    Compliant with
    Recommended control-unit

    Relay contact rating

    Positive temperature coefficient
    160 °C
    IEC 34-11 (BS4999 part 111)
    To comply with IEC 34-11
    (BS4999 part 111)
    Electrical connectors
    17-way connector
    Pump half
    Cable half

    MS type, CA3100E20-29P/F80
    MS type, CA3106E20-29S

    Oil capacity
    Grade of oil
    ISO viscosity grade
    Recommended perfluoropolyether oils
    0.4 litres
    SAE 40
    Fomblin Y25, Krytox 1525
    High vacuum bearings
    Grease type
    Recommended grease
    Fomblin RT15
    Gas temperature
    Exhaust pulsation attenuation
    5 to 150 °C
    30 dB(A)
    5.5 kg
    Exhaust check-valve
    Gas temperature
    Reverse flow leak tightness when clean
    5 to 130 °C

    0.4 (4 x 101
    0.95 kg

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    Not exactly what you're looking for? Innovative Vacuum Solutions is a total solutions provider and can customize or configure your vacuum equipment. Call us toll free at 855-466-6822 and speak to a Sales Engineer to determine your specific needs.


    Our precision vacuum pump rebuild process restores worn or damaged equipment back to the original manufacturers specifications and
    costs a fraction of purchasing new components. Each unit reconditioned by IVS is supported by the most competitive,
    practical warranty in the business: one year from the documented date of installation, not shipment.

    Click here to see the full IVS Business Practical Warranty
    • IVS will safely package your product for shipment at no additional charge.
    • Buyer is responsible for all shipping arrangements and charges.
    • Please allow ten days for delivery from order date to allow for certification and shipping of your equipment.

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