Practical Introduction to Pumping Technology. A basic guide to pumps—from specification to installation and operation

207 Pages·1997·4.105 MB·English

by  Uno Wahren (Auth.)

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2 Chapter
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,noitcirF .9 Head ,snoitaluclaC l .0 Horsepower, .51 Specific Speed, .61
noitcuS Specific Speed, .71 Formulas, Affinity .71
3 Chapter
deriuqeR ataD rof gniyficepS spmuP 19
4 Chapter
pmuP sepyT 12
2 Pumps, Centrifugal l. Axial-Flow dna Pumps, Mixed-Flow .22
wolF-laidaR Pumps, .22 Pumps, Displacement Positive .03
gnitacorpiceR Pumps, .03 Rotary Pumps, .53 Pumps, Special-Purpose .93
5 Chapter
snoitacificepS 42
Sheets, Data .24 ,snoitacificepS .34
6 Chapter
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Centrifugal Pump Curves, .54 Head Curves, Capacity .54
Curves, System .84 Pumps Operating ni Parallel, .84 Pumps
Operating ni Series, .15 Displacement Positive Pump Curves, .45
7 Chapter
stceffE fo ytisocsiV no pmuP ecnamrofreP 55
Viscosity, (Absolute) Dynamic .55 Viscosity, Kinematic .55
Viscosity Units, .55 Industry Preferences, .65
retpahC 8
noitarbiV 16
Terms and Definitions, 6 l. Testing Procedures, .26
Vibration Limits, .36 Induced Piping Vibrations, .56
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teN evitisoP noitcuS daeH )HSPN( 66
Definition, .66 NPSH Calculations, .66 Additional Requirements, 7 l.
retpahC 01
pmuP tfahS gnilaeS 47
Packed Glands, .47 Mechanical Face Seals, .57 Cyclone Separator, .28
Flush dna Quench Fluids, .28 Stuffing-Box Cooling, .28 Buffer Fluid
Schemes, .28 Face Seal Life Expectancy, .28
retpahC 11
pmuP sgniraeB 38
Bearing Types, .38 Bearing Lubrication, .98 Beating Cooling, I. 9
Bearing Seals, .19
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ygrullateM 29
Corrosion, .29 Pump Materials, .39 Cast Iron, .39 FerSrtieteilc, .39
Martensitic Stainless Steel, .79 Austenitic Stainless Steel, .79
Duplex Stainless Steel, .89 Nonferrous Materials, .89 Titanium, .99
Plastic, .99
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pmuP srevirD 001
Electric Motors, 100. Internal Combustion Engines, 106. Steam
Turbines, Gas 109. Turbines, Hydraulic 111. Drives, .311
Solar Power, .311
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sraeG 411
Parallel Gears, Shaft Right-Angle 114. Gears, .811
Epicyclic Gears, .021
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sgnilpuoC 121
Types of Couplings, 21 l. Typical Service Factors, .721
Chapter 61
pmuP slortnoC 821
Control Valve Types, 128. Capacity Control, 129. Minimum Flow
Bypass, 132. Liquid Level Control, 132. On-Off Control, 133.
Modulating Control, 133. Pressure Control, 133. Surge Control, 134.
Control Selection for Positive Displacement Pumps, .431
Pulsation Dampeners, 136.
Chapter 71
noitatnemurtsnI ,,, 731
Instruments, 137. Annunciators, Alarms, and Shutdowns, .731
Functions, 138. Electrical Area Classification, 139.
Chapter 81
noitatnemucoD 041
Chapter 91
noitcepsnI dna gnitseT 241
General Inspection, 142. Hydrostatic Test, 143. Performance Test, 143.
NPSH Test, 145.
Chapter 02
noitallatsnI dna noitarepO ii 641
Installation, 146. Piping and Valves, 148. Pump Start-up, 149.
Chapter 12
Troubleshooting 151
. . . . . . . . .
Centrifugal Pumps, 151. Reciprocating Pumps, .351
xidneppA 1
elpmaS . pmuP noitacificepS. . . 451
2 Appendix
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3 Appendix
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Appendix 4
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VII ,o
5 Appendix
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6 Appendix
mumixaM elbaiV noitcuS Lifts ta suoiraV sedutitlA 164
7 Appendix
detsegguS List fo srodneV 561
8 Appendix
016-IPA lacinahceM Seal noitacifissalC edoC 571
,secnerefeR 671
,xednI 771
VIII oo.
Chapter I
....... Parameters
This book contains information needed to select the proper pump for a given
application, create the necessary documentation, and choose vendors. Many books
dealing with centrifugal and positive displacement pumps exist. Almost all these
books cover pump design and application in great detail, and many are excellent.
This author does not intend to compete head to head with the authors of these books,
but to supply a compact guide that contains all the information a pump user or appli-
cation engineer will need in one handy, uncomplicated reference book.
This book assumes the reader has some knowledge of hydraulics, pumps, and
pumping systems. Because of space limitations, all hydraulic and material property
tables cannot be included. However, excellent sources for hydraulic data include
Hydraulic Institute Complete Pump Standards and Hydraulic Institute Engineering
Data Book.
Hydraulics is the science of liquids, both static and flowing. To understand pumps
and pump hydraulics, pump buyers need to be familiar with the following industry
terminology.
erusserP
This term means a force applied to a surface. The measurements for pressure can
be expressed as various functions of psi, or pounds per square inch, such as:
• Atmospheric pressure (psi) = 14.7 psia
• Metric atmosphere - psi x 0.07
• Kilograms per square centimeter (kg/cm )2 - psi x 0.07
• Kilopascals = psi × 6.89
• Bars --- psi x 14.50
Atmospheric Pressure
The pressure exerted on a surface area by the weight of the atmosphere is atmos-
pheric pressure, which at sea level is 14.7 psi, or one atmosphere. At higher alti-
tudes, the atmospheric pressure decreases. At locations below sea level, the atmos-
pheric pressure rises. (See Table 1.1.)
2 Practical Introduction to Pumping Technology
Table 1.1
Atmospheric Pressure at Some Altitudes
mumixaM
Practical
Barometric Suction Lift
edutitlA erusserP tnelaviuqE Head )retaW(
-1,000 fi 2.51 isp 35.2 ft 22 ft
Sea level 7.41 isp 34.0 ft 12 ft
005,1 fi 9.31 isp 32.2 ft 02 fl
3,000 fl 2.31 isp 5.03 ft 81 ft
5,000 ft 2.21 isp 3.82 ft 61 fl
7,000 fi 3.11 isp 26.2 ft 51 fl
8,000 fi 9.01 isp 2.52 ft 41 fl
Note: Water temperature = 75°F
Vacuum
Any pressure below atmospheric pressure is a pahial vacuum. The expression for
vacuum is in inches or millimeters of mercury (Hg). Full vacuum is at 30 in. Hg. To
convert inches to millimeters multiply inches by 25.4.
Vapor Pressure
At a specific temperature and pressure, a liquid will boil. The point at which the
liquid begins to boil is the liquid's vapor pressure point. The vapor pressure (vp) will
vary with changes in either temperature or pressure, or both. Figure 1.1 shows the
vapor pressure for propane as 10.55 psi at 60°F. At 120°F the vapor pressure for
propane is 233.7 psi.
Gauge Pressure
As the name implies, pressure gauges show gauge pressure (psig), which is the
pressure exerted on a surface minus the atmospheric pressure. Thus, if the absolute
pressure in a pressure vessel is 150 psia, the pressure gauge will read 150 - 14.7, or
135.3 psig.
Absolute Pressure
This is the pressure of the atmosphere on a surface. At sea level, a pressure gauge
with no external pressure added will read 0 psig. The atmospheric pressure is 14.7
psia. If the gauge reads 51 psig, the absolute pressure will be 51 + 14.7, or 29.7 psia.
Parameters 3
1ooo
800
600
5OO
400 --4oo
m
'-.-~2oo ~i
• ~14o =
-...,--, i oo ~-
w u)
~6o ILl
-5o IE
's°o I ............::.::::.:::::::::::::::::::: ........... i
"~40 III
- 40 1 ............ i ............ ~ 0
= i i:~
~'20
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! ........ i?
Ikl
8
m 6 ~ ~ ~ : : : : i : : : z ~ .... ,~.
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Io" ,
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3
U
m i ..... /,/"'q .... ~,-'i ......... : .... I ....... ! ........... ~ ........ 25- =
2i .............. i ........
w
:::::::::::::::::::::::::::::===================================
1.0 ! ..::::::':C :,,.:.:.:.~:.. ~,
============================================== 2r
• 80 ........1 ........ .............i ... i
i .................. i ~ ......... .... ! ............. i ................ i ................. ! ................ i ................. i ................ ~ ............... i ................ i ............ ! -s.92
,60 .........i ....... ...........! .....
..i .......... i~........ i ...... L ........ !. .... .~..... L ........ ! ............ i ........ _J
.4.o. 5o ..........i .i...:...:::.::,~7~ i ........ i ................... ! ............... ~ ................ !! ................ _~ ;;............... .... ~29.,.. ~- 2~ ac:
i:/L: .......... .....i ...... ~ :.......... ........! ...... ........i .... i ======================== ................ ~ .... i':29z"
03. ...........! .... i-4-
.............i ... .........i ... ""92'-~"
i 1....7 ".°..
....... i ...... ....... i ................ i ............... ! ................. i ................ .i ................ i TM
, lo .................................................................................................................................................................... 29.72*
-60 - 30 0 30 60 90 120 150 18,0 210 240
TEMPERATUREm°F
detmrDeR with permission from
J. F. PrilChi~rd & Company.
Kansas .ytwC nJfossiM
Figure 1.1 Vapor Pressure of Various Liquids, --60°F to 240°F (Courtesy of the Hydraulic
Institute)
Flow
This term refers to the liquid that enters the pump's suction nozzle. Flow (Q)
measurements are U.S. gallons per minute (USgpm or gpm) and can be converted
as follows:
Practical Introduction to Pumping Technology
OOOI
. . ................................................ ] ................ ; ................ ........i ................ ' ......... " '°
500
~o~ , i ) ! i i , ......... , ....... ~ !~ !!!! :!: - ~o
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<---z ' ! t ~ i ! ! . ! I ! !,,od
i ~ ............~ ....... ~ ............ .I ............... ! ........ .............~... ; i ..i.... , .............
il '''i'ii~.'~* !i~ii.~. .i.....~ii ii.~ ! i ! i ~ °°"os*~l!~ '
.,o.o .............. ::::::::::::::::::::::::::::::::::::::::::: ........ :....~ . .. ...:.... ........~ ..... ......................~ ......
....... .............'.:'.''.'I. ..... .'i..
- o, ~::~ :::::::::::::::::::::::: ii ....:
............. ......i .. .............i ... W .................... ......' .. ' ....
M' i'i~i ~" ..........................." .. ~ 41
e' , ...." .. ..........! .... i' ................i . ...........i .. ...!... o,
. . . . . . . . . . . . . . . . . .....................I .. ....................... ..I .. ,
i' I i : ........... ....i ... ...~ ....... ! . . . . . . . .
~ lo i ~5"
= e l'-~--'L--: .... ========================================= /''"~" ....... .........................~ ... ~ ~0"
. . . . .....:::::!--~ ...... ~ ......... i:: :::::::::::::::::::::::::::::::::::::::::
......... ~,,...... .........~ .. ..~...i.. ............................~ ................... i:-,,-
!~ 7..!7:7!:.: :.7!!!!!! -:7::: :!:~:7:: ::!::::::.:!7: ::
' . 20 >.
" 7 !~ ' ~, : i ! ..... i~ I
'i i i: i
..................... o~...........i ..... ...........i .. ..... ................................~ .i ...... i . . ! .. . .. .. . .. . . . .. . .. .. . . . [-{-{"~ ............... ........i . .................... .............~ .i ....... .......i ... .....~ ... "82 (z 3
....,o' ......... ...............~ ................i .. i ' ' .......... ." ...... L---~::i_:i
.4o ........ .i ....... ...........i .. .........~ ... .............! .. ..............i .. 29."I
.~o'~-i-::L.I~::;.:~ ................. ......../........'........./.. I .... .........i .. ...............~ . ..... ........i ................ .! - ...........i ..... ............~ .. -;i ~2"~.~,
.,o~--~--~. ! .........i ..... ..........i .. ! i i .....
.........................................................; ...... .................i ... .....i ...... ...................~ .... .: ... 29 5"
~ ~' ...... ..~ ................. ..i ..............i .. i ~
..........,.0 ...........~ . ~ ./.~" ....... { ~ . . . . . . . . . . . . . . . . . .................... ..!' .. .............i . i i i ~ i ~ i ~ ; i -.~ ~r z
-180 -150 -120 -90 -60 -30 0 30 60
TEMPERATURE-.--OF
Fleprinieli with i)efmllsiOn from
the Byron Jlckson Pump Oiv,sion,
Borg-Warner noitarop'~oC
Figure 1.2 Vapor Pressure of Various Liquids, -180*F to 60*F (Courtesy of the Hydraulic
Institute)
• Imperial gallons per minute - USgpm × 1.200
• Cubic meters per hour (m3/hr) - USgpm x 0.227
• Liters per second (L/sec) - USgpm x 0.063
• Barrels per day (one barrel -- 42 gal) - USgpm x 34.290
The pump's flow capacity varies with impeller width, impeller diameter, and
pump revolutions per minute (rpm).
Parameters 5
Discharge Pressure
This is the pressure measured at the pump's discharge nozzle. Measurements may
be stated in:
Psig
•
• kg/cm 2
• Bars
• Kilopascals
Discharge Head
Measured in feet or meters, the discharge head is the same as the discharge pres-
sure converted into the height of a liquid column.
Total Differential Head
The difference between the discharge head and the suction head is the total differ-
ential head (TDH), expressed in feet or meters.
Net Positive Suction Head
The net positive suction head (NPSH) available is the NPSH in feet available at the
centerline of the pump inlet flange. The NPSH required (NPSHR) refers to the NPSH
specified by a pump manufacturer for proper pump operation. (See Chapter 9.)
Density
This term refers to the mass per unit volume measured in pounds per cubic foot at
68°F or in grams per milliliter at 4°C.
Specific Gravity
Dividing the weight of a body by the weight of an equal volume of water at 68°F
yields specific gravity (sp gr). If the data is in grams per milliliter, the specific gravi-
ty of a body of water is the same as its density at 4°C.
Suction Head
The height of a column of liquid upstream from the pump's suction nozzle's cen-
terline is known as the suction head. It may also be the suction pressure, in psig, con-
verted to suction head, in feet. Feet or meters measure suction head.
6 Practical Introduction to Pumping Technology
Table 1.2
Specific Gravity of Some Liquids
Temperature cificepS Weight
diuqiL F* ytivarG )lag/bI(
Acetone 68.0 0.792 6.60
Aniline 68.0 220.1 15.8
Carbon tetrachloride 68.0 595.1 13.28
Coconut oil 59.0 0.926 17.7
Corn oil 59.0 0.925 7.70
Cottonseed oil 60.8 0.926 17.7
Ether 77.0 0.708 5.90
Fuel oil (No. )1 60.0 0.8004).850 6.70-7.10
Fuel oil (No. 2) 60.0 0.810--0.910 6.70-7.60
Gasoline 60.0 0.700-0.760 5.80--6.30
Glucose 77.0 445.1 12.86
Glycerin 32.0 062.1 10.49
Hydrochloric acid* 60.0 312.1 10.10
Kerosene 68.0 0.820 6.83
Linseed oil 68.0 0.930 7.80
Molasses 68.0 1.470 12.20
Olive oil 59.0 0.920 7.66
Soy bean oil 59.0 0.927 7.72
Sulfuric acid t 64.0 438.1 72.51
Tar 68.0 002.1 10.00
Seawater tt 59.0 020.1 8.54
Water (0°C) 39.0 000.1 8.34
Water (20°C) 68.0 0.998 8.32
%4.34* solution
t87.0% solution
ttMay vary. Specific gravity of water ni eht Arabian Gulf si .30.1
Suction Pressure
This refers to the pressure, in psig, at the suction nozzle' s centerline. For instance,
the pressure developed by a booster pump hooked up in series with a main pump is
the suction pressure of the main pump measured at suction nozzle centerline.
Suction Lift
The maximum distance of a liquid level below the impeller eye that will not cause
the pump to cavitate is known as suction lift. Because a liquid is not cohesive, it can-
not be pulled. Instead, the pump impeller, pistons, plungers, or rotors form a partial
vacuum in the pump. The atmospheric pressure (14.7 psi, or 34 ft) pushes the liquid
into this partial vacuum. Because of mechanical losses in the pump, suction lifts are
always less than 34 ft.
Velocity Head
This term refers to the kinetic energy of a moving liquid at a determined point in a
pumping system. The expression for velocity head is in feet per second (ft/sec) or
meters per second (m/see). The mathematical expression is: