What is a centrifugal pump?

Three basic components:

Volute, casing, body– or Diffuser

Impeller– or impellers

Driver (motor)

Centrifugal Pumps

Pump Impeller

Vanes

Direction ofrotation

Centrifugal Pumps

Typical single suction impeller

Centrifugal Pumps

Single suction impeller

Centrifugal Pumps

Impeller Types

•Open•Semi-open•Closed

- Single suction- Double suction

•Non-clogging•Axial flow•Mixed flow

Centrifugal Pumps

Full Diameter Impeller

Rotation

Impeller

Blades

Vt

V

r

Vs

Vr = Radial Velocity

Vt = Tangential Velocity

Vs = Vector Sum Velocity

Centrifugal Pumps

Impeller and volute

Suction Eye

Cutwater

Arrows represent thedirection of water flow Discharge

Nozzle

Centrifugal Pumps

End Suction Pump

Series 1510Series 1510

• 26 sizes– To 4400 gpm– To 520 ft TDH– To 150 HP To 8”x10”– General Purpose

Motor

Centrifugal Pumps

Section View

Bell & GossettSeries 1510

Standard Construction

Bell & GossettSeries 1510

Standard ConstructionGaugeTaps

GaugeTaps

Centrifugal Pumps

Close-Coupled PumpClose-Coupled Pump

Series 1531 PumpSeries 1531 Pump

– 20 sizes– To 2600 gpm– To 520 ft TDH– To 60 HP– To 6”x8”– Special Purpose

Motor

Centrifugal Pumps

Large, Line Mounted Pump

Series 80Series 80

– Close coupled– 18 sizes– To 2600 gpm– To 410 ft TDH– To 60 HP– To 8”x8”– Special Purpose

Motor

Centrifugal Pumps

Multi-stage pumps

Bell & GossettSeries 3550

Bell & GossettSeries 3550

•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

Centrifugal Pumps

Multi-stage pump

Bell & GossettSeries 3550

Bell & GossettSeries 3550

“Diffusers”

Centrifugal Pumps

Vertical Turbine• Submersible

– 48 Models– 5 - 14 bowls– 40 - 2000 gpm– 25 - 300 feet head

• Lineshaft– 88 Models– 5-20” bowls– 4 Styles– 20 - 10,000 gpm– 7 - 200 feet head

Centrifugal Pumps

Double Suction Pump

Bell & GossettSeries HSC

Bell & GossettSeries HSC

– 37 sizes– To 12500 gpm– To 840 ft TDH– To 1000 HP– To 14”x18”– General Purpose Motor

Centrifugal Pumps

Typical Split Case Pump- Section ViewTypical Split Case Pump- Section View

Centrifugal Pumps

Double Suction Pump

Series VSCSSeries VSCS

Series VSCSeries VSC

– 17 sizes– To 8000 gpm– To 400 ft TDH– To 600 HP– To 12”x14”– General Purpose Motor

Centrifugal Pumps

VSC Pump- Section ViewVSC Pump- Section View

Centrifugal Pumps

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

Standard construction

Bell & GossettSeries 1510

StandardConstruction

Bell & GossettSeries 1510

StandardConstruction

Centrifugal Pumps

Seals

Shaft

ProcessFluid

Leakage

Environment VesselWall

Centrifugal Pumps

B&G Pump Construction

Standard construction, any impeller– Mechanical seal– Internally flushed, seal cavity– Variety of seal materials

Centrifugal Pumps

Ceramic Seal InsertGraphite Seal RingCompression Ring

Impeller

Retainer (Sec Seal)

Gasket

Mechanical Seal

Rotary Assy

Stationary Assembly

Secondary Seal (Seal Bellows)

Centrifugal Pumps

Seal CavitySeal Cavity

Centrifugal Pumps

Standard construction

Bell & GossettSeries 1510

StandardConstruction

Bell & GossettSeries 1510

StandardConstruction

Centrifugal Pumps

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

Internally Flushed Mechanical Seals

Bell & GossettSeries HSC3

StandardConstruction

Bell & GossettSeries HSC3

StandardConstruction

Centrifugal Pumps

Pump Construction

Stuffing box construction, any impeller– External flush lines

» Internal or External Fluid

– Compression packing rings– Single flushed mechanical seal

Centrifugal Pumps

Packing

Shaft

ProcessFluidLeakag

e

Environment

Vessel Wall

Centrifugal Pumps

Stuffing box with packing

Centrifugal Pumps

Packing Installation

Centrifugal Pumps

Bypass Flush Line

Bell & GossettSeries HSC-S

Bell & GossettSeries HSC-S

Centrifugal Pumps

Liquid-Abrasives Separator

Centrifugal Pumps

What’s “suitable”…?

Impeller– 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

Angular Misalignment

Centrifugal Pumps

Parallel or Offset Misalignment

Centrifugal Pumps

Suction Piping Detail

5 dia.

1. Pipe supported2. Length of

suction piping allows even impeller loading

RIGHT WRONG

1. Pipe weight hangs on pump flange.

2. Short suction pipe results in uneven impeller loading.

Centrifugal Pumps

Why 5 diameters?

Single SuctionImpeller

Centrifugal Pumps

Installation

Typical installation

Elbow Support(Anchor to Base)

Solid Base Foundation

Flow

Pump Motor Hoist Beam

Trolley with ManualHook-Type Hoist

Triple Duty Valve

Suction Diffuser

Centrifugal Pumps

Vertical Turbine PumpDriverDriver

DischargeHead

DischargeHead

ColumnColumn

BowlAssembly

BowlAssembly

Comments?Questions?

Observations?