PUMP TROUBLESHOOTING

Brian GongolDJ Gongol & Associates, Inc.

July 14, 2014

Ankeny Annual Water ConferenceDMACC/Ankeny

Quick survey

Are you here for water, wastewater, or both?

Sir Arthur Conan Doyle (as Sherlock Holmes)

"Once you eliminate the impossible,whatever remains, no matter how improbable,

must be the truth."

Handout

Pump troubleshooting flowchart

All pump problems are either mechanical...

...or hydraulic

Secondarily, they are either internal...

...or external to the pump

How to tell a mechanical problem

Take away the water

How to tell a hydraulic problem

Take measurements

Mechanical problems - internal to the pump

Bearings

Seals

Packing

Tightness of fit

Suction flap valves

Debris

Internal rubbing

Friction

Mechanical problems - external to the pump

Motors

Controls

Alignment

Balance

Transmission

Belts

Sheaves

Couplings

Valves (throttling)

Valves (isolation)

Valves (air-release)

Piping

Rotation

Jay-Z had 99 problems

We've come up with about 50...and this is halftime

Hydraulic problems - internal to the pump

Recirculation

Clearances

Wearplate wear

Wear ring wear

Volute wear

Impeller wear

In at least three flavors...

Chemical attack

Abrasion

Cavitation*

Cavitation damage happens inside the pump...but it's almost always caused outside the pump

Hydraulic problems - external to the pump

Suction side or discharge side

Hydraulic problems - external - suction

NPSH

NPSHa (net) = Atmospheric pressure- vapor pressure- safety factor- total dynamic suction lift- NPSHr for the pump

Atmospheric pressure

Heat/vapor pressure

Air entrainment

Air in high spot

Turbulence

Vortexing

Minimum submergence

Plugged suction

Debris

Horizontal runs

Valves

Leaks

Changes to fluid properties

For instance...

Gases in solution

Surfactants

Viscosity

Specific gravity

Froth/foam/bubbles

Hydraulic problems - external - discharge

Handout

Engineering data booklet

Valves

Leaks/breaks

Sediment

Debris

Changes to effective pipe diameter

Caused by...

Air

Ice

Corrosion

Scaling

Buildup

Tools to assist in your investigation

Impeller condition: Excess wear

Impeller condition: Suction cavitation

Impeller condition: Discharge cavitation

Shaft breakage

Seal failure

Strange or unwelcome noises

Strange or unwelcome noises

Suction cavitation

Discharge cavitation

Surges

The scream

Use all of your available senses (minus taste)

Record performance

Keep pump curves handy

Gauge readings make a huge difference

Gauge readings make a huge difference

Look in the direction of change

Was the change gradual or abrupt?

Some are dead giveaways,others just point in the right direction

Gauge case studies

Gauge case studies

The prime that took forever

Gauge case studies

Gauge case studies

The prime that took forever The hole in the suction line

Gauge case studies

Gauge case studies

The prime that took forever The hole in the suction line The plugged suction

Gauge case studies

Gauge case studies

The prime that took forever The hole in the suction line The plugged suction

The forcemain failure

Gauge case studies

Gauge case studies

The prime that took forever The hole in the suction line The plugged suction

The forcemain failure The sedimentation

inclination

Gauge case studies

Gauge case studies

The prime that took forever The hole in the suction line The plugged suction

The forcemain failure The sedimentation

inclination The bubble, bubble, toil,

and trouble

Gauge case studies

Gauge case studies

The prime that took forever The hole in the suction line The plugged suction

The forcemain failure The sedimentation

inclination The bubble, bubble, toil,

and trouble The surge-and-slam

Gauge case studies

Always divide and conquer

Questions?

Thank you for coming!

Thank you for your attention!

Contact us anytime with questions

Brian Gongol DJ Gongol & Associates 515-223-4144 info@djgongol.com

References:

Photo: Mechanic tightening nut (public domain) http://loc.gov/pictures/resource/fsac.1a35263/

All other photos are original work by and copyright reserved to Brian Gongol

Slide 1Slide 2Slide 3Slide 4Slide 5Slide 6Slide 7Slide 8Slide 9Slide 10Slide 11Slide 12Slide 13Slide 14Slide 15Slide 16Slide 17Slide 18Slide 19Slide 20Slide 21Slide 22Slide 23Slide 24Slide 25Slide 26Slide 27Slide 28Slide 29Slide 30Slide 31Slide 32Slide 33Slide 34Slide 35Slide 36Slide 37Slide 38Slide 39Slide 40Slide 41Slide 42Slide 43Slide 44Slide 45Slide 46Slide 47Slide 48Slide 49Slide 50Slide 51Slide 52Slide 53Slide 54Slide 55Slide 56Slide 57Slide 58Slide 59Slide 60Slide 61Slide 62Slide 63Slide 64Slide 65Slide 66Slide 67Slide 68Slide 69Slide 70Slide 71Slide 72Slide 73Slide 74Slide 75Slide 76Slide 77Slide 78Slide 79Slide 80Slide 81Slide 82Slide 83Slide 84Slide 85Slide 86Slide 87Slide 88Slide 89Slide 90Slide 91Slide 92Slide 93Slide 94Slide 95Slide 96Slide 97Slide 98Slide 99Slide 100Slide 101Slide 102Slide 103Slide 104Slide 105Slide 106Slide 107Slide 108Slide 109Slide 110