II. Core Basic Parameters 

Air extraction rate: 30–2500 L/s (108–9000 m³/h). Reference test conditions: inlet pressure 100 Pa, intake temperature 20℃. The deviation between the measured value and the nominal value is ≤ ±5% 

2. Maximum pressure: ≤ 5×10⁻² Pa (when paired with standard pre-stage pump operation) 

3. Working pressure range: 1 Pa - 1×10⁴ Pa. It is recommended that the regular working pressure be no more than 1330 Pa. 

4. Maximum allowable pressure difference: 4000–5300 Pa (Different models have corresponding pressure differences, to prevent overload damage) 

5. Speed range: 2900 r/min (constant speed synchronous operation) 

6. Motor type: Y series three-phase asynchronous motor. Customized versions for explosion-proof and variable-frequency applications are available. 

7. Temperature rise control: Under rated operating conditions, continuous operation for 2 hours. The bearing temperature shall not exceed 75℃, the surface temperature of the pump body shall not exceed 90℃, and the overall temperature rise shall not exceed 40℃. 

8. Noise Index: ≤ 85 dB(A), Effective Value of Vibration Velocity ≤ 4.5 mm/s 

9. Working environment temperature: -10℃ to 45℃ 

10. Environmental humidity: ≤ 85% RH (no condensation) 

III. Structural and Material Parameters 

• Pump body / end cover material: HT300 gray cast iron, with tensile strength of ≥ 200 MPa. It is highly rigid and resistant to deformation. The surface has undergone rust removal, phosphating treatment and anti-corrosion coating. 

•Rotor material: QT600 ductile iron. It has undergone double-sided dynamic balance testing, with a balance accuracy of G6.3 grade. The rotor operates smoothly without any vibration. 

•Rotor shaft material: 45# quenched and tempered steel, hardness HB220~250, radial round runout ≤ 0.02mm, strong load-bearing capacity 

• Clearance Design: The clearance between the rotor and the pump chamber, as well as between the rotor itself, is 0.15–0.30mm. There is no friction and the sealing performance is excellent. 

• Sealing method: The shaft end adopts a labyrinth oil seal / mechanical seal. The pump chamber and the bearing chamber are flexibly isolated from each other, preventing oil emulsification and leakage. 

• Lubrication method: The bearings and gearbox are externally lubricated, and there is no oil in the pump chamber, ensuring the cleanliness of the vacuum environment. 

• Protection device: Standardly equipped with an overflow bypass valve, which automatically controls the pressure difference between the inlet and outlet to achieve automatic overload protection. 

IV. Interface Specification Parameters 

Air intake diameter: DN50, DN80, DN100, DN150, DN200, DN250 

Exhaust pipe diameter: DN40, DN50, DN80, DN100, DN150, DN20 

European standard: RF concave standard flange. Customizable with KF, ISO-K and other vacuum-specific interfaces as per requirements. Installation direction can be flexibly adjusted. 

V. Detailed Parameter Table of Typical Models of the ZJ Series

VI. Applicable Conditions and Customized Services 

1. Dischargeable medium: Clean air, steam, inert gas, non-corrosive organic vapors. Sensitive to no dust or condensate. By changing the material of the flow passage components and the anti-corrosion coating, corrosive gases can be discharged. 

2. Intake medium temperature: Standard ≤ 80℃, Customizable high-temperature resistant model (≤ 120℃) 

3. Applicable scenarios: High vacuum demand scenarios such as vacuum coating, vacuum smelting, vacuum degassing, vacuum drying, chemical distillation, electronic and semiconductor industries, food preservation, etc. 

4. Customization Options: Customizable in terms of Ex d IIB T4 explosion-proof type, variable frequency speed control type, anti-corrosion spray/inner coating type, and special diameter customization type; can be combined with vertical oil-free reciprocating pumps and other front-stage pumps to form a complete vacuum unit set. 

5. Ancillary Services: Offer a comprehensive package of services including equipment installation and commissioning, operation and maintenance training, after-sales maintenance and repair, and overall design of the vacuum system. 

VII. Operating Precautions 

• It is strictly prohibited to start the Roots vacuum pump alone without a preceding pre-stage pump. The pre-stage pump must first reduce the system pressure to the allowable value before the Roots vacuum pump can be started. 

During operation, closely monitor the pressure difference at the inlet and outlet, the temperature rise of the pump, and the load of the motor. It is strictly prohibited to operate beyond the pressure difference limit or the temperature limit. 

Regularly check the oil levels and quality of the gearbox and bearing lubricants. Replace the deteriorated lubricating oil in time to prevent lubrication failure. 

When the machine is shut down, it should be stopped synchronously with the previous pump, and the system should be vented to release pressure. The cooling water valve should be closed to prevent the backflow of the medium. 

|Service hotline: 0533-8225516  1506431898