- Email: [email protected]
Technical definitions associated with pumps – part one
F E A T U R E P U M P D E F I N I T I O N S
4ECHNICAL DEFINITIONS ASSOCIATED WITH PUMPS n PART ONE -UCH CONFUSION EXISTS BECAUSE %NGLISH THE WORLDS TECHNICAL LANGUAGE IS USED MOSTLY BY ENGINEERS WHO SPEAKWRITE %NGLISH AS A SECOND LANGUAGE $EFINITIONS OF SOME IMPORTANT TECHNICAL TERMS HAVE BECOME DISTORTED AND THIS LEADS TO CONFUSION IN IMPORTANT COMMUNICATIONS )N THE FIRST OF A SERIES OF ARTICLES PUMP CONSULTANT "RIAN .ESBITT EXPLAINS COMMON TERMS USED IN CONNECTION WITH PUMP APPLICATION AND PUMP DESIGN
)
AM REALLY LUCKY ) LEARNT %NGLISH AS MY FIRST LANGUAGE AND MY BACKGROUND HAS ALWAYS BEEN ENGINEERING %NGLISH IS A TERRIBLE LANGUAGE TO LEARN BECAUSE IT INCLUDES MANY WORDS THAT HAVE NEARLY THE SAME MEANING "EFORE ) STARTED FORMAL ENGINEERING TRAINING ) ALREADY HAD A BROAD KNOWLEDGE OF GENERAL MECHANICAL ENGINEERING -Y FIRSTHAND EXPERIENCE WITH PUMPS HAS SHOWN ME THAT COMMUNICATIONS CAN BE VERY DIFFICULT WHEN CUSTOMERS AND SUPPLIERS DESCRIBE THE SAME THING BY DIFFERENT TERMS 7HEN WRITING MULTINATIONAL STANDARDS IT IS PREFERRED TO AGREE THE %NGLISH VERSION FIRST )T IS MUCH EASIER FOR ENGINEERS TO TRANSLATE FROM %NGLISH RATHER THAN INTO %NGLISH 4HE LANGUAGE PROBLEM EXISTS EVEN WITH FUNDAMENTAL CONCEPTS THAT
ARE ESSENTIAL TO UNDERSTAND WHEN DESCRIBING PUMP APPLICATIONS AND WRITING SPECIFICATIONSx AND PURCHASE ORDERS
-ATTER "EFORE WE CAN CONSIDER PUMPS THE MAIN CONCERN HERE WE MUST START AT A MUCH EARLIER POINT BECAUSE THE FUNDAMENTALS OF PHYSICAL PROPERTIES ARE REGULARLY INCORRECTLY DESCRIBED "EFORE WE CAN DISCUSS MACHINES WE MUST THINK ABOUT @MATTER WHAT EVERYTHING IS MADE OF -ATTER IS NOT ONLY WHAT PUMPS ARE MADE OF BUT WHAT PUMPS @PUMP AS WELL -ATTER EXISTS IN SEVERAL PHYSICAL VARIETIES ATOMIC VARIETIES DONT NECESSARILY CONCERN US HERE AND PUMPS HANDLE MOST OF THEM
3OLID
&IGURE ! HEAVY DUTY CENTRIFUGAL PUMP FOR CLEAN LIQUID APPLICATIONS
¥ %LSEVIER ,TD !LL RIGHTS RESERVED
4HE @COLD STATE OF MATTER A STATE OF FIXED VOLUME AND FIXED SHAPE @&IXED IS POSSIBLY TOO RIGID A TERM HERE #ONSIDER RUBBER AND MANY ELASTOMERS THE SHAPE CAN BE CHANGED QUITE EASILY BY THE APPLICATION OF SMALL FORCESx BUT WHEN THE FORCES ARE RELEASED THE SOLID RETURNS TO ITS ORIGINAL SHAPEx SOMETIMES 3OLIDS CAN BE ELASTIC OR PLASTIC ELASTIC SOLIDS RETURN TO THE ORIGINAL SIZE SHAPE AFTER DEFORMATION PLASTIC SOLIDS REMAINED DEFORMED 6OLUME CAN BE MODIFIED REDUCED BY THE APPLICATION OF $ FORCES PRESSURE OR INCREASED BY HEATING 3OLIDS ARE VERY VARIABLE AND THE DIFFERENCE IN PHYSICAL PROPERTIES CAN BE CRUCIALLY IMPORTANT WOULD A PUMP MADE OF
GOLD BE BETTER THAN A PUMP OF CAST IRON )T WOULD BE MUCH MORE COSTLY AND MUCH MORE CORROSION RESISTANT BUT WOULD IT WORK IN PRACTICE 0UMPING SAND IS VERY DIFFERENT TO PUMPING COAL "UT BEWARE .ATURAL PRODUCTS SUFFER HUGE VARIATIONS IN PROPERTIES EXPERIENCE FROM ONE SITE MAY NOT BE TRANSFERABLE
h4HE FUNDAMENTALS OF PHYSICAL PROPERTIES ARE REGULARLY INCORRECTLY DESCRIBEDv ,IQUID )F A SOLID IS HEATED THE FREEZING POINT IS REACHED AND THEN THE SOLID BECOMES LIQUID .OT ALL SOLIDS HAVE A STABLE LIQUID PHASE 'ENERALLY LIQUID CAN BE CONSIDERED AS HAVING A FIXED VOLUME WITH A VARIABLE SHAPE 4HE VOLUME CAN BE REDUCED USUALLY ONLY VERY SLIGHTLY BY THE APPLICATION OF PRESSURE AND INCREASED BY HEATING 3OME LIQUIDS LIKE WATER CHANGE SHAPE VERY EASILY AND FLOW READILY n LOW VISCOSITY /THERS LIKE HEAVY OIL DONT CHANGE SHAPE QUICKLY AND DONT FLOW AS EASILY n HIGH VISCOSITY ,IQUIDS LIKE WATER ARE .EWTONIAN VISCOSITY IS INDEPENDENT OF THE RATE OF SHEAR DECREASES WITH INCREASING TEMPERATURE AND IS SLIGHTLY INFLUENCED BY PRESSURE 3OME LIQUIDS ARE @SHEAR SENSITIVE OR @PSEUDO PLASTIC DONT FLOW EASILY AND CAN BE DAMAGED BY THE PUMPING ACTION 0UMPS FOR THESE LIQUIDS MUST BE SELECTED CAREFULLY
7/2,$ 05-03 !PRIL
F E A T U R E P U M P D E F I N I T I O N S 6APOUR
&LUID MISCONCEPTIONS
)F A LIQUID IS HEATED EVENTUALLY IT WILL BOIL TO PRODUCE VAPOUR 6APOUR IS A GAS LIKE STATE IN THAT THE VOLUME AND SHAPE CHANGE EASILY ! VAPOUR CAN EXPAND TO FILL A CONTAINER BUT IF THE CONTAINER IS TOO BIG A PROPORTION OF THE VAPOUR WILL CONDENSE BACK INTO LIQUID 3ATURATED VAPOUR IS A MIXTURE OF VAPOUR AND LIQUID DROPLETS AND OCCURS WHEN VAPOUR COEXISTS ABOVE BOILING LIQUID 6APOUR IS A @COMPLICATED GAS AND MAY NOT OBEY THE NORMAL GAS LAWS
9OU MAY HAVE NOTICED THAT ONE VERY POPULAR TECHNICAL TERM HAS NOT BEEN MENTIONED @FLUID &LUID IS NOT ONE OF THE STATES OF MATTER IT DESCRIBES A
'AS ! STATE OF MATTER ACHIEVED BY HEATING BEYOND THE DRY VAPOUR PHASE TO A TEMPERATURE HIGHER THAN THE CRITICAL TEMPERATURE IN WHICH THE MOLECULES MOVE RANDOMLY TO FILL THE VOLUME AVAILABLE ! GAS CANNOT BE CONVERTED TO LIQUID BY INCREASING THE PRESSURE 4HE VOLUME OF A GAS CHANGES EASILY TO ACCOMMODATE CHANGES IN THE CONFINING VOLUME 4HE PRESSURE AND TEMPERATURE OF AN IDEAL OR PERFECT GAS CAN BE CALCULATED BY USING THE CHARACTERISTIC EQUATION AND "OYLES AND #HARLES ,AWS )DEAL GAS PROPERTIES CAN BE CONVERTED TO REAL GAS PROPERTIES BY INCLUDING COMPRESSIBILITY FACTORS IN THE CHARACTERISTIC EQUATION SEE BOX OVER THE PAGE
GROUP OF STATES PLUS MIXTURES OF STATES &LUID IS DERIVED FROM @FLUIDITY THE ABILITY TO FLOW AND THE SHAPE OF FLUIDS IS DETERMINED BY THE CONTAINMENT &LUID BROADLY INCLUDES LIQUIDS
4ABLE 0ROPERTIES OF MATTER 3TATE
3OLID
#HANGE OF STATE .O PRACTICALLY
,IQUID
6APOUR
'AS
0LASMA
9ES
9ES
.O
.O
WITH PRESSURE 3HAPE
!LMOST FIXED
6ARIABLE
6ARIABLE
6ARIABLE
6ARIABLE
6OLUME
!LMOST FIXED
3LIGHTLY VARIABLE
6ARIABLE
6ARIABLE
6ARIABLE
$ENSITY
(IGH TO LOW
(IGH TO LOW
,OW
,OW
,OW
4ENSILE
6ERY HIGH TO LOW
!BOUT ZERO
:ERO
:ERO
:ERO
!BOUT ZERO
6ARIABLE
6ERY HIGH
6ERY HIGH
6ERY HIGH
STRENGTH &LUIDITY #OMPRESSIBILITY
6ERY LOW TO LOW
,OW TO MEDIUM
(IGH
(IGH
(IGH
0LASTIC
9ES
.O
.O
.O
.O
9ES
.O
.O
.O
.O
9ES
.O
.O
.O
.O
DEFORMATION ,OCALIZED STRESSING 5NI DIRECTIONAL STRESS #AN APPLY TO SOME MIXED MATTER HANDLED BY PUMPS
0LASMA ! GASEOUS STATE OF MATTER ACHIEVED BY HEATING GAS TO VERY HIGH TEMPERATURES CAUSING IONIZATION 0LASMAS CONTAIN POSITIVE AND NEGATIVE CHARGES IN APPROXIMATELY EQUAL NUMBERS 4HEY ARE GOOD CONDUCTORS OF ELECTRICITY AND ARE AFFECTED BY MAGNETIC FIELDS 0LASMAS ARE CHARACTERIZED BY THEIR ABILITY TO RAPIDLY CHANGE SHAPE AND THE ALMOST TOTAL ABSENCE OF TENSILE STRENGTH OR VISCOSITY ,IKE A GAS A PLASMA WILL EXPAND TO FILL THE VOLUME AVAILABLE BUT UNUSUALLY CAN BE SEPARATED FROM CONTAINMENT SURFACES BY MAGNETIC FIELDS 0LASMAS CAN BE COMPRESSED BY MAGNETIC FIELDS WITHOUT USING SOLID SURFACES 0LASMAS DONT OCCUR IN THE AVERAGE INDUSTRIAL PUMP APPLICATION WHEREAS ALL THE OTHER STATES FREQUENTLY OCCUR SIMULTANEOUSLY
7/2,$ 05-03 !PRIL
WWWWORLDPUMPSCOM
F E A T U R E P U M P D E F I N I T I O N S VAPOURS GASES AND PLASMAS PLUS MIXTURES OF SOLIDS IN LIQUIDVAPOUR GASPLASMA &LUID IS NOT A SPECIFIC TERM IT IS A GENERALIZATION &LUID HAS INSIDIOUSLY WORKED ITS WAY INTO THE %NGLISH LANGUAGE 7HEN YOURE UNWELL AND VISIT YOUR DOCTOR HE MAY GIVE YOU SOME TABLETS AND INSTRUCT YOU @TO TAKE PLENTY OF FLUIDS (E IS INCORRECT AND IN ERROR (E MEANS @DRINK PLENTY OF LIQUIDS THIS IS NOT THE SAME 7E ARE ALL CONTINUOUSLY SURROUNDED BY FLUIDS THAT ARE LARGELY OUTSIDE OUR CONTROL 7E GENERALLY CANT CONTROL ATMOSPHERIC AIR OR HOW WE @TAKE IT )F YOUR DOCTOR WAS REALLY WORRIED ABOUT @FLUIDS HE WOULD GIVE YOU OXYGEN AND AN OXYGEN MASK 7E COULD ALL STOP USING THE TERM @FLUID AND BENEFIT FROM IMPROVED MORE ACCURATE COMMUNICATIONS &LUID AND LIQUID ARE NOT INTERCHANGEABLE 5SE @FLUID AT YOUR OWN RISK
h&LUID IS NOT A SPECIFIC TERM IT IS A GENERALIZATION USE IT AT YOUR OWN RISKv 9OU MAY SEE ADVERTS OR SPECIFICATIONS FOR SOFTWARE THAT MAY BE USED FOR
SYSTEM ANALYSIS UTILIZING PERFECT FLUIDS 0ERFECT FLUIDS MAY HAVE ZERO VISCOSITY BE INCOMPRESSIBLE HOMOGENEOUS AND PURE 3OME SOFTWARE HAS A LIMITED CONSIDERATION OF MASS !S PERFECT FLUIDS DONT EXIST IN THE REAL WORLD THIS TYPE OF SOFTWARE IS OF LIMITED PRACTICAL VALUE $ONT MAKE IMPORTANT DECISIONS BASED ON THE OUTPUT FROM SUCH SOFTWARE YOU CANT AFFORD THE INSURANCE CLAIMS @,IQUID IS NOT ALWAYS THE MOST APPROPRIATE TERM TO USE IN CONNECTION WITH SOME PUMP APPLICATIONS )MAGINE SHOVELLING A PILE OF MIXED MATTER INTO A HOPPER THAT DIRECTS THE MASS INTO A SCREW CONVEYOR WHICH FEEDS A @PUMP 0UMPS NOT NECESSARILY PUMPS IN GENERAL CAN HANDLE OR COPE WITH A VAST RANGE OF MIXED MATTER BUT THE PRECISE NATURE OF THE MASS MUST BE DESCRIBED PRIOR TO PURCHASING THE @PUMP 4HE PUMP MAY NOT WORK RELIABLY OR EFFICIENTLY OR SAFELY IF MIXED MATTER IS APPLIED TO A @WATER PUMP 5SEFUL ALTERNATIVE TERMS TO @LIQUID INCLUDE @PUMPED MEDIUM AND @PRODUCT 4HE %UROPEAN 3TANDARDS !UTHORITY #%. HAVE COINED A NEW TERM @AGRIFOODSTUFF WHICH IS APPLIED TO ANY MATERIAL FOR HUMANANIMAL CONSUMPTION
2EMEMBER 4HE ONUS IS ON THE PURCHASERUSER TO ACCURATELY DESCRIBE WHAT THE PUMP IS GOING TO HANDLE 4HINGS NOT DESCRIBED ARE NOT COVERED BY GUARANTEES AND WARRANTIES
0UMP TERMINOLOGY !T THIS POINT ) CAN INTRODUCE SOMETHING YOU MAY HAVE EXPECTED TO SEE SOONER
0UMP &IGURE ! CENTRIFUGAL PUMP SPECIFICALLY FOR HANDLING LIQUID SOLID MIXTURES
! DEVICE OR MACHINE USED TO INCREASE THE ENERGY LEVEL OF A LIQUID 4HE TERM @LIQUID IS USED INTENTIONALLY HERE BECAUSE PUMPS ARE DESIGNED SPECIFICALLY TO HANDLE PURE .EWTONIAN LIQUIDS n UNLESS THE MANUFACTURERS SPECIFICATION STATES OTHERWISE 2EMEMBER A PUMP WILL BE TESTED WITH PURE CLEAN COLD LIQUID OR TAP WATER OF WHICH MORE LATER UNLESS A SPECIAL TEST PROCEDURE IS INVOKED 0UMPS FOR MIXED MATTER APPLICATIONS ARE BEST TRIALLED AT SITE IF SUITABLE ACCURATE INSTRUMENTATION IS AVAILABLE 4HE TERM @PUMP APPLIES TO THE MACHINE ITSELF USUALLY LIMITED BY ITS TERMINAL POINTS INLET CONNECTION OUTLET CONNECTION DRIVE SHAFT AND
WWWWORLDPUMPSCOM
7/2,$ 05-03 !PRIL
F E A T U R E P U M P D E F I N I T I O N S SOMETIMES CONNECTIONS TO SEALS 3OME PUMPS ARE INTEGRAL WITH THE DRIVER AND THE DRIVER MAY HAVE TERMINAL POINTS
0UMP UNIT ! PUMP WITH POWER TRANSMISSION AND DRIVER MOUNTED ON A BASEPLATE SKIDTRAILER 4HE @UNIT INCLUDES ANY MOUNTED AUXILIARY EQUIPMENT
#OMPRESSOR ! DEVICE OR MACHINE USED TO INCREASE THE ENERGY LEVEL OF GASES OR VAPOURS #OMPRESSORS GENERALLY EXPECT GASES VAPOURS TO BE CLEAN AND FREE FROM SOLIDS OR LIQUID DROPLETS 5NEXPECTED INCLUSIONS MAY REDUCE PERFORMANCE RELIABILITY AND SAFETY
h)F WE NEED THE FUTURE TO BE RELIABLE AND
SYSTEM )TS A SYSTEM THAT INCLUDES A COMPRESSOR TO MOVE REFRIGERANT GAS 4HE TERM @PUMP HAS BECOME VERY MUCH MISUSED 4HIS IS BECAUSE @COMPRESSOR IS A NEW WORD )T DID NOT ENTER THE %NGLISH ENGINEERING TECHNICAL LANGUAGE AS WE USE IT TODAY UNTIL THE S LONG AFTER THE START OF THE )NDUSTRIAL 2EVOLUTION @#RYOGENIC PUMP IS AN IMPRECISE NAME AND CAN ONLY BE UNDERSTOOD WITH CLARITY BY REVIEWING THE CONTEXT )T MIGHT BE A VACUUM PUMP COMPRESSOR OR IT MIGHT BE A PUMP FOR HANDLING VERY COLD LIQUIDS 4HIS IS A CASE FOR CAREFULLY STUDYING THE APPLICATION @-ECHANICAL PUMP IS A VERY AMBIGUOUS TERM AND SHOULD NOT BE USED @)NDUCTION PUMP IS A TERM DEFINED BY PEOPLE OUTSIDE THE PUMP INDUSTRY AS ANY PUMP THAT RELIES ON ELECTROMAGNETIC INDUCTION THIS IS OBVIOUSLY NOT A
USEFUL PRACTICAL DEFINITION ! ,!3%2 PUMP IS AN ELECTRONIC DEVICE NOT USED FOR HANDLING LIQUIDS ! DATA PUMP IS ) THINK A PIECE OF SOFTWARE USED FOR DATA MINING IN DATABASES 4HE WORLD OF PUMPS IS HUGE AND VERY BROAD 7ITHOUT PUMPS LIFE AS WE KNOW IT WOULD COME TO AN END )F WE NEED THE FUTURE TO BE RELIABLE AND ENERGY EFFICIENT WE ALL NEED TO USE TECHNICAL %NGLISH WITH CLARITY AND PRECISION N
#/.4!#4 "RIAN .ESBITT IS AN INDEPENDENT CONSULTANT SPECIALIZING IN POSITIVE DISPLACEMENT PUMPS (E HAS BEEN INVOLVED WITH PUMPS AND PUMPING SYSTEMS SINCE ! MEMBER OF THE "3) -#% COMMITTEES "RIAN REPRESENTS THE 5+ ON #%. AND )3/ 0$ PUMP COMMITTEES )F YOU WOULD LIKE "RIAN TO REVIEW OR INCLUDE A DEFINITION IN FUTURE ARTICLES HE CAN BE CONTACTED AT BRIANNESBITT BTINTERNETCOM
ENERGY EFFICIENT WE ALL NEED TO USE TECHNICAL %NGLISH WITH CLARITY AND PRECISIONv !MBIGUITIES MISUSE 4HE FOLLOWING ARE COMPRESSORS INFLATOR AIR PUMP BICYCLE PUMP ION PUMP VACUUM PUMP @!IR PUMP MIGHT BE USED AS SHORTHAND FOR @AIR OPERATED PUMP CHECK THE CONTEXT @&OOT PUMP IS COMPLETELY MEANINGLESS WHO WANTS TO PUMP FEET @(AND PUMP IS SHORTHAND FOR @HAND OPERATED PUMP @"ARREL PUMP HAS TWO POPULAR MEANINGS A SMALL PUMP FOR EMPTYING BARRELS OR A BIGGER MUCH MORE COSTLY MULTI STAGE CENTRIFUGAL PUMP THAT MIGHT ALSO BE DESCRIBED AS A RADIALLY SPLIT PUMP @3TEAM PUMP IS AMBIGUOUS IT IS SHORTHAND FOR @STEAM OPERATED PUMP BUT IT IS TOO VAGUE TO BE USEFUL 4HE @HEAT PUMP IS A SPECIAL CASE IT IS NOT A DEVICE OR A MACHINE ITS A
7/2,$ 05-03 !PRIL
WWWWORLDPUMPSCOM
4ECHNICAL DEFINITIONS ASSOCIATED WITH PUMPS n PART ONE -UCH CONFUSION EXISTS BECAUSE %NGLISH THE WORLDS TECHNICAL LANGUAGE IS USED MOSTLY BY ENGINEERS WHO SPEAKWRITE %NGLISH AS A SECOND LANGUAGE $EFINITIONS OF SOME IMPORTANT TECHNICAL TERMS HAVE BECOME DISTORTED AND THIS LEADS TO CONFUSION IN IMPORTANT COMMUNICATIONS )N THE FIRST OF A SERIES OF ARTICLES PUMP CONSULTANT "RIAN .ESBITT EXPLAINS COMMON TERMS USED IN CONNECTION WITH PUMP APPLICATION AND PUMP DESIGN
)
AM REALLY LUCKY ) LEARNT %NGLISH AS MY FIRST LANGUAGE AND MY BACKGROUND HAS ALWAYS BEEN ENGINEERING %NGLISH IS A TERRIBLE LANGUAGE TO LEARN BECAUSE IT INCLUDES MANY WORDS THAT HAVE NEARLY THE SAME MEANING "EFORE ) STARTED FORMAL ENGINEERING TRAINING ) ALREADY HAD A BROAD KNOWLEDGE OF GENERAL MECHANICAL ENGINEERING -Y FIRSTHAND EXPERIENCE WITH PUMPS HAS SHOWN ME THAT COMMUNICATIONS CAN BE VERY DIFFICULT WHEN CUSTOMERS AND SUPPLIERS DESCRIBE THE SAME THING BY DIFFERENT TERMS 7HEN WRITING MULTINATIONAL STANDARDS IT IS PREFERRED TO AGREE THE %NGLISH VERSION FIRST )T IS MUCH EASIER FOR ENGINEERS TO TRANSLATE FROM %NGLISH RATHER THAN INTO %NGLISH 4HE LANGUAGE PROBLEM EXISTS EVEN WITH FUNDAMENTAL CONCEPTS THAT
ARE ESSENTIAL TO UNDERSTAND WHEN DESCRIBING PUMP APPLICATIONS AND WRITING SPECIFICATIONSx AND PURCHASE ORDERS
-ATTER "EFORE WE CAN CONSIDER PUMPS THE MAIN CONCERN HERE WE MUST START AT A MUCH EARLIER POINT BECAUSE THE FUNDAMENTALS OF PHYSICAL PROPERTIES ARE REGULARLY INCORRECTLY DESCRIBED "EFORE WE CAN DISCUSS MACHINES WE MUST THINK ABOUT @MATTER WHAT EVERYTHING IS MADE OF -ATTER IS NOT ONLY WHAT PUMPS ARE MADE OF BUT WHAT PUMPS @PUMP AS WELL -ATTER EXISTS IN SEVERAL PHYSICAL VARIETIES ATOMIC VARIETIES DONT NECESSARILY CONCERN US HERE AND PUMPS HANDLE MOST OF THEM
3OLID
&IGURE ! HEAVY DUTY CENTRIFUGAL PUMP FOR CLEAN LIQUID APPLICATIONS
¥ %LSEVIER ,TD !LL RIGHTS RESERVED
4HE @COLD STATE OF MATTER A STATE OF FIXED VOLUME AND FIXED SHAPE @&IXED IS POSSIBLY TOO RIGID A TERM HERE #ONSIDER RUBBER AND MANY ELASTOMERS THE SHAPE CAN BE CHANGED QUITE EASILY BY THE APPLICATION OF SMALL FORCESx BUT WHEN THE FORCES ARE RELEASED THE SOLID RETURNS TO ITS ORIGINAL SHAPEx SOMETIMES 3OLIDS CAN BE ELASTIC OR PLASTIC ELASTIC SOLIDS RETURN TO THE ORIGINAL SIZE SHAPE AFTER DEFORMATION PLASTIC SOLIDS REMAINED DEFORMED 6OLUME CAN BE MODIFIED REDUCED BY THE APPLICATION OF $ FORCES PRESSURE OR INCREASED BY HEATING 3OLIDS ARE VERY VARIABLE AND THE DIFFERENCE IN PHYSICAL PROPERTIES CAN BE CRUCIALLY IMPORTANT WOULD A PUMP MADE OF
GOLD BE BETTER THAN A PUMP OF CAST IRON )T WOULD BE MUCH MORE COSTLY AND MUCH MORE CORROSION RESISTANT BUT WOULD IT WORK IN PRACTICE 0UMPING SAND IS VERY DIFFERENT TO PUMPING COAL "UT BEWARE .ATURAL PRODUCTS SUFFER HUGE VARIATIONS IN PROPERTIES EXPERIENCE FROM ONE SITE MAY NOT BE TRANSFERABLE
h4HE FUNDAMENTALS OF PHYSICAL PROPERTIES ARE REGULARLY INCORRECTLY DESCRIBEDv ,IQUID )F A SOLID IS HEATED THE FREEZING POINT IS REACHED AND THEN THE SOLID BECOMES LIQUID .OT ALL SOLIDS HAVE A STABLE LIQUID PHASE 'ENERALLY LIQUID CAN BE CONSIDERED AS HAVING A FIXED VOLUME WITH A VARIABLE SHAPE 4HE VOLUME CAN BE REDUCED USUALLY ONLY VERY SLIGHTLY BY THE APPLICATION OF PRESSURE AND INCREASED BY HEATING 3OME LIQUIDS LIKE WATER CHANGE SHAPE VERY EASILY AND FLOW READILY n LOW VISCOSITY /THERS LIKE HEAVY OIL DONT CHANGE SHAPE QUICKLY AND DONT FLOW AS EASILY n HIGH VISCOSITY ,IQUIDS LIKE WATER ARE .EWTONIAN VISCOSITY IS INDEPENDENT OF THE RATE OF SHEAR DECREASES WITH INCREASING TEMPERATURE AND IS SLIGHTLY INFLUENCED BY PRESSURE 3OME LIQUIDS ARE @SHEAR SENSITIVE OR @PSEUDO PLASTIC DONT FLOW EASILY AND CAN BE DAMAGED BY THE PUMPING ACTION 0UMPS FOR THESE LIQUIDS MUST BE SELECTED CAREFULLY
7/2,$ 05-03 !PRIL
F E A T U R E P U M P D E F I N I T I O N S 6APOUR
&LUID MISCONCEPTIONS
)F A LIQUID IS HEATED EVENTUALLY IT WILL BOIL TO PRODUCE VAPOUR 6APOUR IS A GAS LIKE STATE IN THAT THE VOLUME AND SHAPE CHANGE EASILY ! VAPOUR CAN EXPAND TO FILL A CONTAINER BUT IF THE CONTAINER IS TOO BIG A PROPORTION OF THE VAPOUR WILL CONDENSE BACK INTO LIQUID 3ATURATED VAPOUR IS A MIXTURE OF VAPOUR AND LIQUID DROPLETS AND OCCURS WHEN VAPOUR COEXISTS ABOVE BOILING LIQUID 6APOUR IS A @COMPLICATED GAS AND MAY NOT OBEY THE NORMAL GAS LAWS
9OU MAY HAVE NOTICED THAT ONE VERY POPULAR TECHNICAL TERM HAS NOT BEEN MENTIONED @FLUID &LUID IS NOT ONE OF THE STATES OF MATTER IT DESCRIBES A
'AS ! STATE OF MATTER ACHIEVED BY HEATING BEYOND THE DRY VAPOUR PHASE TO A TEMPERATURE HIGHER THAN THE CRITICAL TEMPERATURE IN WHICH THE MOLECULES MOVE RANDOMLY TO FILL THE VOLUME AVAILABLE ! GAS CANNOT BE CONVERTED TO LIQUID BY INCREASING THE PRESSURE 4HE VOLUME OF A GAS CHANGES EASILY TO ACCOMMODATE CHANGES IN THE CONFINING VOLUME 4HE PRESSURE AND TEMPERATURE OF AN IDEAL OR PERFECT GAS CAN BE CALCULATED BY USING THE CHARACTERISTIC EQUATION AND "OYLES AND #HARLES ,AWS )DEAL GAS PROPERTIES CAN BE CONVERTED TO REAL GAS PROPERTIES BY INCLUDING COMPRESSIBILITY FACTORS IN THE CHARACTERISTIC EQUATION SEE BOX OVER THE PAGE
GROUP OF STATES PLUS MIXTURES OF STATES &LUID IS DERIVED FROM @FLUIDITY THE ABILITY TO FLOW AND THE SHAPE OF FLUIDS IS DETERMINED BY THE CONTAINMENT &LUID BROADLY INCLUDES LIQUIDS
4ABLE 0ROPERTIES OF MATTER 3TATE
3OLID
#HANGE OF STATE .O PRACTICALLY
,IQUID
6APOUR
'AS
0LASMA
9ES
9ES
.O
.O
WITH PRESSURE 3HAPE
!LMOST FIXED
6ARIABLE
6ARIABLE
6ARIABLE
6ARIABLE
6OLUME
!LMOST FIXED
3LIGHTLY VARIABLE
6ARIABLE
6ARIABLE
6ARIABLE
$ENSITY
(IGH TO LOW
(IGH TO LOW
,OW
,OW
,OW
4ENSILE
6ERY HIGH TO LOW
!BOUT ZERO
:ERO
:ERO
:ERO
!BOUT ZERO
6ARIABLE
6ERY HIGH
6ERY HIGH
6ERY HIGH
STRENGTH &LUIDITY #OMPRESSIBILITY
6ERY LOW TO LOW
,OW TO MEDIUM
(IGH
(IGH
(IGH
0LASTIC
9ES
.O
.O
.O
.O
9ES
.O
.O
.O
.O
9ES
.O
.O
.O
.O
DEFORMATION ,OCALIZED STRESSING 5NI DIRECTIONAL STRESS #AN APPLY TO SOME MIXED MATTER HANDLED BY PUMPS
0LASMA ! GASEOUS STATE OF MATTER ACHIEVED BY HEATING GAS TO VERY HIGH TEMPERATURES CAUSING IONIZATION 0LASMAS CONTAIN POSITIVE AND NEGATIVE CHARGES IN APPROXIMATELY EQUAL NUMBERS 4HEY ARE GOOD CONDUCTORS OF ELECTRICITY AND ARE AFFECTED BY MAGNETIC FIELDS 0LASMAS ARE CHARACTERIZED BY THEIR ABILITY TO RAPIDLY CHANGE SHAPE AND THE ALMOST TOTAL ABSENCE OF TENSILE STRENGTH OR VISCOSITY ,IKE A GAS A PLASMA WILL EXPAND TO FILL THE VOLUME AVAILABLE BUT UNUSUALLY CAN BE SEPARATED FROM CONTAINMENT SURFACES BY MAGNETIC FIELDS 0LASMAS CAN BE COMPRESSED BY MAGNETIC FIELDS WITHOUT USING SOLID SURFACES 0LASMAS DONT OCCUR IN THE AVERAGE INDUSTRIAL PUMP APPLICATION WHEREAS ALL THE OTHER STATES FREQUENTLY OCCUR SIMULTANEOUSLY
7/2,$ 05-03 !PRIL
WWWWORLDPUMPSCOM
F E A T U R E P U M P D E F I N I T I O N S VAPOURS GASES AND PLASMAS PLUS MIXTURES OF SOLIDS IN LIQUIDVAPOUR GASPLASMA &LUID IS NOT A SPECIFIC TERM IT IS A GENERALIZATION &LUID HAS INSIDIOUSLY WORKED ITS WAY INTO THE %NGLISH LANGUAGE 7HEN YOURE UNWELL AND VISIT YOUR DOCTOR HE MAY GIVE YOU SOME TABLETS AND INSTRUCT YOU @TO TAKE PLENTY OF FLUIDS (E IS INCORRECT AND IN ERROR (E MEANS @DRINK PLENTY OF LIQUIDS THIS IS NOT THE SAME 7E ARE ALL CONTINUOUSLY SURROUNDED BY FLUIDS THAT ARE LARGELY OUTSIDE OUR CONTROL 7E GENERALLY CANT CONTROL ATMOSPHERIC AIR OR HOW WE @TAKE IT )F YOUR DOCTOR WAS REALLY WORRIED ABOUT @FLUIDS HE WOULD GIVE YOU OXYGEN AND AN OXYGEN MASK 7E COULD ALL STOP USING THE TERM @FLUID AND BENEFIT FROM IMPROVED MORE ACCURATE COMMUNICATIONS &LUID AND LIQUID ARE NOT INTERCHANGEABLE 5SE @FLUID AT YOUR OWN RISK
h&LUID IS NOT A SPECIFIC TERM IT IS A GENERALIZATION USE IT AT YOUR OWN RISKv 9OU MAY SEE ADVERTS OR SPECIFICATIONS FOR SOFTWARE THAT MAY BE USED FOR
SYSTEM ANALYSIS UTILIZING PERFECT FLUIDS 0ERFECT FLUIDS MAY HAVE ZERO VISCOSITY BE INCOMPRESSIBLE HOMOGENEOUS AND PURE 3OME SOFTWARE HAS A LIMITED CONSIDERATION OF MASS !S PERFECT FLUIDS DONT EXIST IN THE REAL WORLD THIS TYPE OF SOFTWARE IS OF LIMITED PRACTICAL VALUE $ONT MAKE IMPORTANT DECISIONS BASED ON THE OUTPUT FROM SUCH SOFTWARE YOU CANT AFFORD THE INSURANCE CLAIMS @,IQUID IS NOT ALWAYS THE MOST APPROPRIATE TERM TO USE IN CONNECTION WITH SOME PUMP APPLICATIONS )MAGINE SHOVELLING A PILE OF MIXED MATTER INTO A HOPPER THAT DIRECTS THE MASS INTO A SCREW CONVEYOR WHICH FEEDS A @PUMP 0UMPS NOT NECESSARILY PUMPS IN GENERAL CAN HANDLE OR COPE WITH A VAST RANGE OF MIXED MATTER BUT THE PRECISE NATURE OF THE MASS MUST BE DESCRIBED PRIOR TO PURCHASING THE @PUMP 4HE PUMP MAY NOT WORK RELIABLY OR EFFICIENTLY OR SAFELY IF MIXED MATTER IS APPLIED TO A @WATER PUMP 5SEFUL ALTERNATIVE TERMS TO @LIQUID INCLUDE @PUMPED MEDIUM AND @PRODUCT 4HE %UROPEAN 3TANDARDS !UTHORITY #%. HAVE COINED A NEW TERM @AGRIFOODSTUFF WHICH IS APPLIED TO ANY MATERIAL FOR HUMANANIMAL CONSUMPTION
2EMEMBER 4HE ONUS IS ON THE PURCHASERUSER TO ACCURATELY DESCRIBE WHAT THE PUMP IS GOING TO HANDLE 4HINGS NOT DESCRIBED ARE NOT COVERED BY GUARANTEES AND WARRANTIES
0UMP TERMINOLOGY !T THIS POINT ) CAN INTRODUCE SOMETHING YOU MAY HAVE EXPECTED TO SEE SOONER
0UMP &IGURE ! CENTRIFUGAL PUMP SPECIFICALLY FOR HANDLING LIQUID SOLID MIXTURES
! DEVICE OR MACHINE USED TO INCREASE THE ENERGY LEVEL OF A LIQUID 4HE TERM @LIQUID IS USED INTENTIONALLY HERE BECAUSE PUMPS ARE DESIGNED SPECIFICALLY TO HANDLE PURE .EWTONIAN LIQUIDS n UNLESS THE MANUFACTURERS SPECIFICATION STATES OTHERWISE 2EMEMBER A PUMP WILL BE TESTED WITH PURE CLEAN COLD LIQUID OR TAP WATER OF WHICH MORE LATER UNLESS A SPECIAL TEST PROCEDURE IS INVOKED 0UMPS FOR MIXED MATTER APPLICATIONS ARE BEST TRIALLED AT SITE IF SUITABLE ACCURATE INSTRUMENTATION IS AVAILABLE 4HE TERM @PUMP APPLIES TO THE MACHINE ITSELF USUALLY LIMITED BY ITS TERMINAL POINTS INLET CONNECTION OUTLET CONNECTION DRIVE SHAFT AND
WWWWORLDPUMPSCOM
7/2,$ 05-03 !PRIL
F E A T U R E P U M P D E F I N I T I O N S SOMETIMES CONNECTIONS TO SEALS 3OME PUMPS ARE INTEGRAL WITH THE DRIVER AND THE DRIVER MAY HAVE TERMINAL POINTS
0UMP UNIT ! PUMP WITH POWER TRANSMISSION AND DRIVER MOUNTED ON A BASEPLATE SKIDTRAILER 4HE @UNIT INCLUDES ANY MOUNTED AUXILIARY EQUIPMENT
#OMPRESSOR ! DEVICE OR MACHINE USED TO INCREASE THE ENERGY LEVEL OF GASES OR VAPOURS #OMPRESSORS GENERALLY EXPECT GASES VAPOURS TO BE CLEAN AND FREE FROM SOLIDS OR LIQUID DROPLETS 5NEXPECTED INCLUSIONS MAY REDUCE PERFORMANCE RELIABILITY AND SAFETY
h)F WE NEED THE FUTURE TO BE RELIABLE AND
SYSTEM )TS A SYSTEM THAT INCLUDES A COMPRESSOR TO MOVE REFRIGERANT GAS 4HE TERM @PUMP HAS BECOME VERY MUCH MISUSED 4HIS IS BECAUSE @COMPRESSOR IS A NEW WORD )T DID NOT ENTER THE %NGLISH ENGINEERING TECHNICAL LANGUAGE AS WE USE IT TODAY UNTIL THE S LONG AFTER THE START OF THE )NDUSTRIAL 2EVOLUTION @#RYOGENIC PUMP IS AN IMPRECISE NAME AND CAN ONLY BE UNDERSTOOD WITH CLARITY BY REVIEWING THE CONTEXT )T MIGHT BE A VACUUM PUMP COMPRESSOR OR IT MIGHT BE A PUMP FOR HANDLING VERY COLD LIQUIDS 4HIS IS A CASE FOR CAREFULLY STUDYING THE APPLICATION @-ECHANICAL PUMP IS A VERY AMBIGUOUS TERM AND SHOULD NOT BE USED @)NDUCTION PUMP IS A TERM DEFINED BY PEOPLE OUTSIDE THE PUMP INDUSTRY AS ANY PUMP THAT RELIES ON ELECTROMAGNETIC INDUCTION THIS IS OBVIOUSLY NOT A
USEFUL PRACTICAL DEFINITION ! ,!3%2 PUMP IS AN ELECTRONIC DEVICE NOT USED FOR HANDLING LIQUIDS ! DATA PUMP IS ) THINK A PIECE OF SOFTWARE USED FOR DATA MINING IN DATABASES 4HE WORLD OF PUMPS IS HUGE AND VERY BROAD 7ITHOUT PUMPS LIFE AS WE KNOW IT WOULD COME TO AN END )F WE NEED THE FUTURE TO BE RELIABLE AND ENERGY EFFICIENT WE ALL NEED TO USE TECHNICAL %NGLISH WITH CLARITY AND PRECISION N
#/.4!#4 "RIAN .ESBITT IS AN INDEPENDENT CONSULTANT SPECIALIZING IN POSITIVE DISPLACEMENT PUMPS (E HAS BEEN INVOLVED WITH PUMPS AND PUMPING SYSTEMS SINCE ! MEMBER OF THE "3) -#% COMMITTEES "RIAN REPRESENTS THE 5+ ON #%. AND )3/ 0$ PUMP COMMITTEES )F YOU WOULD LIKE "RIAN TO REVIEW OR INCLUDE A DEFINITION IN FUTURE ARTICLES HE CAN BE CONTACTED AT BRIANNESBITT BTINTERNETCOM
ENERGY EFFICIENT WE ALL NEED TO USE TECHNICAL %NGLISH WITH CLARITY AND PRECISIONv !MBIGUITIES MISUSE 4HE FOLLOWING ARE COMPRESSORS INFLATOR AIR PUMP BICYCLE PUMP ION PUMP VACUUM PUMP @!IR PUMP MIGHT BE USED AS SHORTHAND FOR @AIR OPERATED PUMP CHECK THE CONTEXT @&OOT PUMP IS COMPLETELY MEANINGLESS WHO WANTS TO PUMP FEET @(AND PUMP IS SHORTHAND FOR @HAND OPERATED PUMP @"ARREL PUMP HAS TWO POPULAR MEANINGS A SMALL PUMP FOR EMPTYING BARRELS OR A BIGGER MUCH MORE COSTLY MULTI STAGE CENTRIFUGAL PUMP THAT MIGHT ALSO BE DESCRIBED AS A RADIALLY SPLIT PUMP @3TEAM PUMP IS AMBIGUOUS IT IS SHORTHAND FOR @STEAM OPERATED PUMP BUT IT IS TOO VAGUE TO BE USEFUL 4HE @HEAT PUMP IS A SPECIAL CASE IT IS NOT A DEVICE OR A MACHINE ITS A
7/2,$ 05-03 !PRIL
WWWWORLDPUMPSCOM