1. What is a centrifugal pump?
Three basic components:
Volute, casing, body
or Diffuser
Impeller
or impellers
Driver (motor)

2. Pump Impeller
Direction of
rotation
Vanes
Centrifugal Pumps

3. Typical single suction impeller
Centrifugal Pumps

4. Single suction impeller
Centrifugal Pumps

5. Impeller Types Open Semi-open Closed Single suction Double suction
Non-clogging
Axial flow
Mixed flow
Centrifugal Pumps

6. Impeller Profiles
Specific Speed
HI Standard
Centrifugal Pumps

7. Generally: Maximum efficiency lies in the range:
2000<NS<3000
High head, low capacity pumps:
500<NS<1000
Low head, large capacity pumps:
NS>15000
Centrifugal Pumps

8. Full Diameter Impeller
Rotation
Impeller
Blades Vt Vr Vs
Vr = Radial Velocity
Vt = Tangential Velocity
Vs = Vector Sum Velocity
Centrifugal Pumps

9. Impeller and volute Discharge Nozzle Cutwater Suction Eye
Arrows represent the
direction of water flow
Discharge
Nozzle
Cutwater
Suction Eye
Centrifugal Pumps

10. End Suction Pump 26 sizes To 4400 gpm To 520 ft TDH
To 150 HP To 8”x10”
General Purpose Motor
Series 1510
Centrifugal Pumps

11. Standard Construction
Section View
Bell & Gossett
Series 1510
Standard Construction
Gauge
Taps
Centrifugal Pumps

12. Close-Coupled Pump 20 sizes To 2600 gpm To 520 ft TDH To 60 HP
To 6”x8”
Special Purpose Motor
Series 1531 Pump
Centrifugal Pumps

13. Large, Line Mounted Pump
Close coupled
18 sizes
To 2600 gpm
To 410 ft TDH
To 60 HP
To 8”x8”
Special Purpose Motor
Series 80
Centrifugal Pumps

14. Multi-stage pumps Multi-stage, diffuser design
8 sizes, stainless steel
to 600 gpm
to 1200 ft
to 75 hp, 3500 rpm
many options for suction and discharge nozzles
Bell & Gossett
Series 3550
Centrifugal Pumps

15. Multi-stage pump “Diffusers” Bell & Gossett Series 3550
Centrifugal Pumps

16. Vertical Turbine Submersible 48 Models 5 - 14 bowls 40 - 2000 gpm
feet head
Lineshaft
88 Models
5-20” bowls
4 Styles
,000 gpm
feet head
Centrifugal Pumps

17. Double Suction Pump 37 sizes To 12500 gpm To 840 ft TDH To 1000 HP
To 14”x18”
General Purpose Motor
Bell & Gossett
Series HSC
Centrifugal Pumps

18. Typical Split Case Pump- Section View
Centrifugal Pumps

19. Double Suction Pump Series VSC 17 sizes To 8000 gpm Series VSCS
To 400 ft TDH
To 600 HP
To 12”x14”
General Purpose Motor
Series VSCS
Centrifugal Pumps

20. VSC Pump- Section View
Centrifugal Pumps

21. Pump Construction Standard construction, any impeller Mechanical seal
Internally flushed, seal cavity
Variety of seal materials
Stuffing box construction, any impeller
External flush lines
Compression packing rings
Single flushed mechanical seal
Centrifugal Pumps

22. Standard construction
Bell & Gossett
Series 1510
Standard
Construction
Centrifugal Pumps

23. Seals Vessel Environment Wall Shaft Process Fluid Leakage
Centrifugal Pumps

24. B&G Pump Construction Standard construction, any impeller
Mechanical seal
Internally flushed, seal cavity
Variety of seal materials
Centrifugal Pumps

25. Secondary Seal (Seal Bellows)
Mechanical Seal
Stationary Assembly
Graphite Seal Ring
Ceramic Seal Insert
Compression Ring
Retainer (Sec Seal)
Gasket
Secondary Seal (Seal Bellows)
Impeller
Rotary Assy
Centrifugal Pumps

26. Seal Cavity
Self-flushing mechanical seals were first introduced to the HVAC market by Bell & Gossett. This feature maximizes seal face lubrication, heat dissipation, and debris removal without vulnerable, external flushing lines. The internal flushing action passes two and a half to three times the liquid over the seal faces compared to externally flushed stuffing box configurations.
Centrifugal Pumps

27. Standard construction
Bell & Gossett
Series 1510
Standard
Construction
Centrifugal Pumps

28. Limits On Seal Performance
Temperature of the flushing water.
225ºF to 250ºF
System pH.
7 to 9 for ceramic seals
up to 11 for tungsten carbide seals
Concentration of dissolved solids.
TDS less than 1000 ppm
Concentration of suspended solids.
Less than 20 ppm
Silica, less than 10 ppm
Centrifugal Pumps

29. Internally Flushed Mechanical Seals
Bell & Gossett
Series HSC3
Standard
Construction
Centrifugal Pumps

30. Pump Construction Stuffing box construction, any impeller
External flush lines
Internal or External Fluid
Compression packing rings
Single flushed mechanical seal
Centrifugal Pumps

31. Packing Environment Vessel Wall Shaft Process Fluid Leakage
Centrifugal Pumps

32. Stuffing box with packing
Centrifugal Pumps

33. Packing Installation
Centrifugal Pumps

34. Bypass Flush Line
Bell & Gossett
Series HSC-S
Centrifugal Pumps

35. Liquid-Abrasives Separator
Centrifugal Pumps

36. What’s “suitable”…? Impeller Volutes
Single suction or double suction.
Volutes
Base mounted or in-line.
Internally flushed or stuffing box.
Single stage or multi stage.
Packing, seal or wet rotor.
Centrifugal Pumps

37. Angular Misalignment
Centrifugal Pumps

38. Parallel or Offset Misalignment
Centrifugal Pumps

39. Suction Piping Detail 5 dia. RIGHT WRONG 1. Pipe supported
2. Length of suction piping allows even impeller loading
1. Pipe weight hangs on pump flange.
2. Short suction pipe results in uneven impeller loading.
Centrifugal Pumps

40. Why 5 diameters?
Single Suction
Impeller
Centrifugal Pumps

41. Installation The NPT or flanged is rated for 175 MWP.
The Grooved Pump end to Grooved System Suction Diffusers have a maximum working pressure of 300 psi.
The maximum temperature is 250°F.
Centrifugal Pumps

42. Typical installation
BELL & GOSSETT LEADS THE SUCTION DIFFUSER MARKET WITH THE MOST COMPLETE LINE OFFERED TODAY
WE LEAD THE MARKET DUE TO
OUR COMPETITIVE PRICING AND
OUR SUPERIOR DESIGN WHICH HAS SET THE INDUSTRY STANDARD
IT IS A PRODUCT THAT HELPS SIMPLIFY THE DESIGN, INSTALLATION, AND MAINTENANCE OF AN HVAC SYSTEM
IT’S AN ACCESSORY THAT SHOULD BE QUOTED WITH EVERY PUMP

43. Flow Elbow Support Solid Base Foundation Pump Motor Hoist Beam
Trolley with Manual
Hook-Type Hoist
Flow
Triple Duty Valve
While smaller inline pumps do provide additional installation flexibility, larger inline pumps require very special consideration due to there size, weight and unique servicing needs. These units must be mounted at floor level to allow for service access and inspection. In addition, the weight of the major components is significant and floor mounting is critical to provide servicing capability. In addition, the dimensional foot print on larger inline pumps is substantially larger then a hydraulically equivalent vertical split case pump. In tight space conditions the floor space necessary for a larger inline pump is going to exceed that of a typical vertical split case double suction pump.
For example…...
Suction Diffuser
Elbow Support
(Anchor to Base)
Solid Base Foundation

44. Vertical Turbine Pump Driver Discharge Head Column Bowl Assembly
Centrifugal Pumps

45. Comments? Questions? Observations?