MDK Series BB3 Multistage Split Case Pump

The MDK series BB3 type pump is a horizontal, radially split, between-bearings, multistage centrifugal pump built in accordance with API 610 standard, designed for high-pressure, heavy-duty continuous service in petroleum, chemical, power, and water industries.

Its casing is axially split along the shaft centerline, allowing easy maintenance without dismantling the motor or piping. The pump adopts double suction or multistage segmented structure to achieve high head and stable operation. Supported by bearings at both ends, it provides strong radial and axial load capacity, ensuring low vibration and long service life.

Parameters
Flow range: 20~2500m

Head range: 60-1200m

Applicable temperature:-40~+200℃

Design pressure: 16MPa

Designed speed: 2980rpm\1480rpm

Conveying medium: Liquid with the solid contentnot exceeding 3%

Applications
General residential & industrial water supply & transferring; Agricultural irrigation & drainage, Flood discharge & Emergency drainage; Civil water treatment, Waterworks, Sea water desalination; Air-conditioning, Fire-fighting facilities, High building water supply; Oil & Gas & Chemical processing, Abrasive liquids transferring; Power plant water circulation, Cooling tower & Hot water transferring Mining, Boiler feeding, etc.

Structural characteristics

1. The pump casing is a horizontal multi-stage split centrifugal structure, with the suction inlet and thedischarge outlet below the pump shaft line, so that it canopen the pump coverto remove the rotor out fomaintenance instead of moving the motor and pipelineduring maintenance and overhau, and the pump seatand pump cover do not need to be dismantled for bearing and mechanical seal maintenance.

2. The pump casingis the centerine supportstructure,and only a small uniform deformation of theoverall shell will be caused due to change of mediumtemperature, which will have little impact on the overalunit.

3. The double volute pressurized water chamberautomatically balances the radial force, to eliminate thealternating stress acting on the rotor.

4. With the half-spiral structure suction chamberand lengthened pre-spin length,the anti-cavitationperformance of the pump can be improved.

5. In addition to ensuring that the pump pressurelevel requirements are met,the wall thickness of thepump also leaves enough surplus corrosion margin.

6. The rotor is rigidly installed, and all parts areinstalled together for dynamic balancing to reduce theunit vibration caused by unbalance.

7. The keyway installed on the main shaft impelleris alternately distributed in 120 circles to reduce theinfluence of the keyway on the rigidity of the shaft.

8. The rotor shaft is extended in a taperedstructure,which is convenient for the installation anddisassembly of the coupling.

9. When the first-stage impeller is single suction,the pump is an even number,and the impellers areinstalled back to back.When the first-stage impeller isdouble suction,the pump is an odd number, and theimpellers at all stages, except for the first-stage pump,are installed back to back,to ensure the shafinstallation of the pump group. Force balance.

10. The bearing structure is divided into three forms:

a.Rolling radial bearing + rolling motion axialthrust bearing;

b.Creep radial bearing+rolling axial thrustbearing;

c.Radial thrust sliding bearing;

11. Bearing service life: more than 25,000 hours ofoperation under rated conditions.

12. Lubrication mode: Thin oil lubrication.

13. Cooling mode:natural cooling,air cooling, water cooling,forced cooling of thin oil station. Thecooling mode is selected according to the load size, thetemperature of the conveying medium and other factors.

14. A positioning oil cup is set on the bearing, totimely supplement the lubricating oil in operation.

15. The pump shaft end is sealed by mechanicalseal or packing seal, which is selected according to the medium, temperature and use environment. Packing seal is configured only according to user requirements.

16. The machine sealflushing and leakageprotection system canensure thecontinuous andtrouble-free operation of the pump in the workingenvironment.

17. The balance pipe is connected with the suctionend through thehigh-pressure end decompressionchamber to balance the sealing pressure at the high-pressure end.

18. The machine seal flushing scheme is selectedaccording to the medium and working conditions.

19. Monitoring system:

a. Temperature monitoring: front and rear bearingspump casings.

b. Vibration monitoring: front and rear bearings

c. Leakage monitoring: mechanical sealing.

20. Transmission and mounting parts:

a. The pump is directly driven by the extendeddiaphragm coupling and the driving machine, and otherforms of transmission can also be used according touser needs.

b. The grouting steel common base plate is usedfor joint skid installation of the pump and the drivingmachine and the control system, etc.

c. The openable couplingprotective cover isinstalled on the common base plate.

d. The pump and the driving machine and thecontrol system with the pump unit room are integrated

Main Parts Configuration

The pump could be applied to transfer different kinds of liquid by customized wet parts, here followed our recommendation of main configuration: