130 131

CONVERSION TABLE

Reference

1

132 133

SI UNIT

Reference

Item

Force

Pressure

Mass

Speed

Viscosity

Dynamic Viscocity

Specific heat

Work energy

Power

Existing Unit (SI Unit)

1kgf ( = 9.80665N )

1kgf/cm3 ( = 0.0980665MPa )1mAq ( = 9.80665kPa )1mmHg ( = 0.133322kPa )

1kW.h ( = 3.6MJ )1kgf.m ( = 9.80665J )1kcal ( = 4.18605KJ )1kgf.m/s ( = 9.80665W )1PS ( = 7.355 x 10-1kW )1kcal/h ( = 1.16279 x 10-3kW )

Mass: 1kg ( =1kg )

Revolution speed: 1r.p.m.( =1min-1 )

1cP ( = 1mPa.S )

1cSt ( = 1mm2/s )

1kcal/kg. c ( = 4.18605kJ/(kg.K) )

SI Unit

1N ( = 0.101972kgf )

1MPa ( = 10.1972kgf/cm2 )1kPa ( = 0.101972mAq)1kPa ( = 7.50062mmHg )

1MJ ( = 2.77778 x 10-1kW.h )1J ( = 1.01972 x 10-1kgf.m )1KJ ( = 2.38889 x 10-1kcal )1kW ( = 1.01972 x 102kgf.m/s )1kW ( = 1.35962PS )1kW ( = 8.60 x 102kcal/h)

Mass: 1kg ( =1kg )

Revolution speed: 1min-1( =1r.p.m. )

1mPa.S ( = 1cP )

1mm2/s ( = 1cSt )

1kJ/(kg. K) ( = 0.238889kcal / (kg. c) )

TRANSLATION TO UNIT (SI)

TO DETERMINE: AMPERES, HORSEPOWER, KILOWATTS, AND KVA

To find

Amperes when horsepower is known

Direct current Single-phase Three-phase

H.P. x 746E x %Eff.

H.P. x 746E x %Eff. x P.F.

H.P. x 7461.73 x E x %Eff. x P.F.

Amperes when kilowatt is known

K.W. x 1000E

I x E1000

I x E x %Eff.746

K.W. x 1000E x P.F.

K.W. x 10001.73 x E x P.F.

Amperes when KVA is known

K.W. x 1000E

K.W. x 10001.73 x E

Kilowatts I x E x P.F.1000

I x E x x 1.73 x P.F.1000

KVA I x E 1000

I x E x 1.731000

Horsepower output I x E x %Eff. x P.F.746

I x E x 1.73 x %Eff.x P.F.746

Where:A : AmperesE : Volts%Eff. : per cent efficiencyP.F. : Power Factor

K.W. : KilowattsKVA : Kilo-volt-amperesH.P. : HorsepowerI : Current

ELECTRICAL DATA

2

132 133

SI UNIT

Reference

Item

Force

Pressure

Mass

Speed

Viscosity

Dynamic Viscocity

Specific heat

Work energy

Power

Existing Unit (SI Unit)

1kgf ( = 9.80665N )

1kgf/cm3 ( = 0.0980665MPa )1mAq ( = 9.80665kPa )1mmHg ( = 0.133322kPa )

1kW.h ( = 3.6MJ )1kgf.m ( = 9.80665J )1kcal ( = 4.18605KJ )1kgf.m/s ( = 9.80665W )1PS ( = 7.355 x 10-1kW )1kcal/h ( = 1.16279 x 10-3kW )

Mass: 1kg ( =1kg )

Revolution speed: 1r.p.m.( =1min-1 )

1cP ( = 1mPa.S )

1cSt ( = 1mm2/s )

1kcal/kg. c ( = 4.18605kJ/(kg.K) )

SI Unit

1N ( = 0.101972kgf )

1MPa ( = 10.1972kgf/cm2 )1kPa ( = 0.101972mAq)1kPa ( = 7.50062mmHg )

1MJ ( = 2.77778 x 10-1kW.h )1J ( = 1.01972 x 10-1kgf.m )1KJ ( = 2.38889 x 10-1kcal )1kW ( = 1.01972 x 102kgf.m/s )1kW ( = 1.35962PS )1kW ( = 8.60 x 102kcal/h)

Mass: 1kg ( =1kg )

Revolution speed: 1min-1( =1r.p.m. )

1mPa.S ( = 1cP )

1mm2/s ( = 1cSt )

1kJ/(kg. K) ( = 0.238889kcal / (kg. c) )

TRANSLATION TO UNIT (SI)

TO DETERMINE: AMPERES, HORSEPOWER, KILOWATTS, AND KVA

To find

Amperes when horsepower is known

Direct current Single-phase Three-phase

H.P. x 746E x %Eff.

H.P. x 746E x %Eff. x P.F.

H.P. x 7461.73 x E x %Eff. x P.F.

Amperes when kilowatt is known

K.W. x 1000E

I x E1000

I x E x %Eff.746

K.W. x 1000E x P.F.

K.W. x 10001.73 x E x P.F.

Amperes when KVA is known

K.W. x 1000E

K.W. x 10001.73 x E

Kilowatts I x E x P.F.1000

I x E x x 1.73 x P.F.1000

KVA I x E 1000

I x E x 1.731000

Horsepower output I x E x %Eff. x P.F.746

I x E x 1.73 x %Eff.x P.F.746

Where:A : AmperesE : Volts%Eff. : per cent efficiencyP.F. : Power Factor

K.W. : KilowattsKVA : Kilo-volt-amperesH.P. : HorsepowerI : Current

ELECTRICAL DATA

COMMONLY USE PUMP FORMULAS

Reference

HEAD AND PRESSURE

BRAKE HORSEPOWER OR BRAKE KILOWATTTo determine the horsepower or kilowatt required, the following formulas can be used:

= )tf( daeH = )m( daeH

Head (m) = Head (ft) x 0.305

Head (ft) = Head (m) x 3.28

a) Brake horsepower =

b) Brake horsepower =

c) Brake Kilowatt =

Where n = Speed, Q = Flow, H = Head, P = Power

FORMULAS

V =

Total Head (ft) x IGPM x Sp. Gr.pump efficiency % x 3300

pressure (kPa) or9.8 x specific gravitypressure (bar) x 10.2

specific gravity ;pressure (psi) x 2.31

specific gravity

Total Head (ft) x USGPM x Sp. Gr.pump efficiency % x 3960

Total Head (m) x m3/hr x Sp. Gr.pump efficiency % x 367

GPM x 0.321F

2.31 x psiSp. Gr.*

= GPM x 0.409(I.D.)2

V2 = 2 gH

H =

1.134 x inches of mercurySp. Gr.*

H =

141.5131.5 + AP 1 (Baume)

Sp. Gr.*=

ABBREVIATIONS

V

GPM

F

I.D.

g

H

HP

Sp. Gr.

psi

velocity in feet / second

gallons per minute

area in square inches

inside diameter of pipe in inches

32.16 ft. /sec. /sec.

head in feet

horsepower

Specific gravity*

pounds per square inch

=

=

=

=

=

=

=

=

=

AFFINITY LAW

USEFUL FORMULAS

Q2Q1

n2n1

= H2H1

n2n1

=, ( )2 P2P1

n2n1

=, ( )3

* These equivalents are based on a specific gravity of 1 for water at 62 F for English units and a specific gravity of 1 for water at 15 C for metric units. They can be used, with little error, for cold water of any temperature between 32 F and 80 F.

3

134 135

CALCULATING PUMP HEAD

Reference

HAZEN-WILLIAMS FORMULA

CALCULATING FRICTION LOSSES

H= I f = I . L

Hf =

10.666Q1.85

C1.85 . D4.87

10.666Q1.85 .LC1.85 . D4.87

Where :I : Hydraulic gradientQ : Quantity of flow (m3/s)C : Flow velocity coefficient (Refer to Table)

Tar-epoxy coated pipes: 130Mortar lined pipes: 130Vinyl chloride pipes: 150

D : Pipe diameter (m)L : Total length of pipeline (m)

Where :Hatm : atmospheric pressure (m)NPSHr : net positive suction head required by the pump (m)Hf : friction loss in suction line and fittings (m)Hv : liquid vapour pressure (m)Hs : safety margin allowance (m)

Table Flow velocity Coefficients for Various Type Pipes (For Straight Pipe)

Pipe type (inside surface)

Flow velocity coefficientMax. value Min. value Standard value

Cast iron pipe (without coating)*

Steel pipe (without coating)*

Coal tar coated pipe (cast iron)*

Tar-epoxy coated pipe (steel)**

Mortar lined pipe (steel, cast iron)

Centrifugal reinforced concrete pipe

Rolling press reinforced concrete pipe

Pressed concrete pipe

Asbestos cement pipe

Hard vinyl chloride pipe***

Hard polyethylene pipe***

Reinforced plastics pipe***

150 80 100

150 90 100

145 80 100___ ___ 130

150 120 130

140 120 130

140 120 130

140 120 130

160 140 140

160 140 150

170 130 150

160 ___ 150

This formula is applied where flows are in transitional range (of roughness/smoothness), and is commonly applicable to the calculation of loss heads for relatively long pipelines such as irrigation water lifting, city water supply, or sewage water pipelines.

CALCULATING MAXIMUM SUCTION LIFT

For mortar lined pipe : c = 110For coated steel pipe : c = 110 (bends included)For vinyl chloride pipe : c = 110

Suction Lift (m) = Hatm - NPSHr - Hf - Hv - Hs

Notes :* Changes due to time passage have been taken

into account.** The coating method should conform to

JWWAK-115-1974, and preferably the coating thickness should be 0.5mm or more. In addition, where adequate management/control is expected to be difficult for coating work at site, this should not be applied.

*** C = 150 should be applied to pipes with a diameter of 150mm or smaller.

The values listed on the table do not include loss heads due to pipe shapes, such as bends, expansion, reduction in diameters, etc. Therefore, when obtaining the total loss heads, such individual losses as described above should be added to the straight line loss. However, the following values may be used to calculate approximate loss values if bends or other shape changes cannot be accurately estimated.

4

5

136

Recommended outlet diameter

Recommended inlet diameter

Pressure drops (Pc) in metres, water column, for every hundred metres of new piping in cast iron.Speed of the liquid in the piping in metres/second (V m/s).

CAPACITY

m3/h

3

6

9

12

15

18

21

24

27

30

36

42

48

54

60

75

90

105

120

135

150

165

180

210

240

270

300

360

420

480

540

600

660

720

780

840

900

960

1020

1080

1140

1200

Pc %Vm/sPc %Vm/sPc %Vm/sPc %Vm/sPc %Vm/sPc %Vm/sPc %Vm/sPc %Vm/sPc %Vm/sPc %Vm/sPc %Vm/sPc %Vm/sPc %Vm/sPc %Vm/sPc %Vm/sPc %Vm/sPc %Vm/sPc %Vm/sPc %Vm/sPc %Vm/sPc %Vm/sPc %Vm/sPc %Vm/sPc %Vm/sPc %Vm/sPc %Vm/sPc %Vm/sPc %Vm/sPc %Vm/sPc %Vm/sPc %Vm/sPc %Vm/sPc %Vm/sPc %Vm/sPc %Vm/sPc %Vm/sPc %Vm/sPc %Vm/sPc %Vm/sPc %Vm/sPc %Vm/sPc %Vm/s

25 32 40 50 60 70 80 90 100 125 150 175 200 225 250 275 300 350 400 450 500 600 700 800 900 1000

17 6 1.6 0.54 0.25 0.13 0.06 0.03 0.021.70 1.03 0.67 0.43 0.29 0.22 0.16 0.13 0.10

24 6 2 0.9 0.43 0.21 0.13 0.08 0.0261.70 1.03 0.67 0.43 0.29 0.22 0.16 0.13 0.10

12.5 4.3 1.8 0.9 0.46 0.25 0.15 0.06 2.08 1.32 0.89 0.65 0.5 0.39 0.32 0.20 20 7 32 1.5 0.75 0.44 0.25 0.09 0.032.76 1.76 1.19 0.88 0.67 0.53 0.43 0.27 0.18

22 8.8 4.2 2.2 1.3 0.75 0.26 0.1 0.053.35 2.08 1.54 1.17 0.93 0.75 0.48 0.32 0.24

12 5.2 2.4 1.25 0.7 0.42 0.15 0.0 2.2 1.49 1.1 0.87 0.66 0.54 0.34 0. 24 17 7 3.5 1.7 1 0.6 0.2 0.08 2.64 1.78 1.3 1 0.78 0.64 0.4 0.28

12 5,7 3 1.7 1 0.36 0.14 0.07 2.38 1.76 1.34 1.06 0.86 0.54 0.36 0.28 14 7 3,5 2 1.25 0.42 0.17 0.08 2.7 1.97 1.45 1.17 0.96 0.6 0.42 0.31 17 8.2 4.2 2.5 1.5 0.5 0.2 0.09 2.98 2.2 1.74 1.32 1.08 0.68 0.48 0.34

16 8.5 4,5 2.7 0.85 0.33 0.18 0.08 3.07 2.34 1.85 1.5 0.96 0.66 0.48 0. 37 21 10 6 3,6 1.2 0.45 0.22 0.12 0.063.51 2.68 2.12 1.72 1.08 0.72 0.56 0.43 0.34 25 13.5 7.6 4.5 1.5 0.55 0.28 0.14 0.083.94 3 2.34 1.92 1.2 0.84 0.63 0.48 0.38

16 9 5.5 1.8 0.7 0.33 0.17 0.13.32 2.64 2.16 1.36 0.96 0.68 0.53 0.42

20 12.5 3.8 1.45 0.74 0.36 0.2 0.14 0.083.97 3.24 2.04 1.44 1.02 0.8 0.63 0.51 0.42 26 16.5 5.3 1.95 0.9 0.47 0.27 0.16 0.1 4.6 3.74 2.41 1.68 1.22 0.93 0.74 0.59 0.49

21.5 6.9 2.6 1.2 0.61 0.36 0.2 0.14 0.08 4.31 2.72 1.93 1.35 1.06 0.84 0.68 0.56 0.47 26 9 3.3 1.5 0.76 0.45 0.25 0.17 0.1 4.81 1.07 2.13 1.56 1.19 0.95 0.76 0.63 0.53

11 4 1.9 0.95 0.55 0.3 0.21 0.12 0.06 3.44 2.36 1.74 1.34 1.05 0.86 0.70 0.59 0.43 13 4.7 2.2 1.13 0.65 0.37 0.24 0.15 0.08 3.75 2.61 1.91 1.46 1.15 0.94 0.77 0.65 0.48 15.2 5.5 2.6 1.3 0.76 0.43 0.29 0.18 0.09 4.09 2.83 2.08 1.59 1.26 1.02 0.84 0.71 0.52 21 7.4 3.5 1.8 1.1 0.6 0.37 0.24 0.12 0.06 4.70 3.32 2.43 1.86 1.49 1.19 0.98 0.82 0.61 0.47

9.4 4.3 2.3 1.3 0.75 0.48 0.3 0.15 0.08 3.78 2.77 2.12 1.68 1.36 1.12 0.95 0.69 0.53 12 5.5 2.8 1.62 0.9 0.58 0.35 0.18 0.09 4.26 3.13 2.39 1.90 1.53 1.26 1.07 0.78 0.59 14 7.5 3.4 2 1.1 0.74 0.46 0.22 0.11 0.07 4.75 3.47 2.66 2.10 1.71 1.40 1.18 0.86 0.67 0.53

9 4.7 2.8 1.6 1 0.65 0.32 0.16 0.09 0.05 4.15 3.17 2.53 2.04 1.68 1.41 1.04 0.79 0.63 0.51

8.5 4.9 2.9 1.9 1.2 0.6 0.3 0.17 0.09 0.04 4.24 3.36 2.72 2.24 1.90 1.38 1.06 0.84 0.69 0.47 11 6.5 3.7 2.35 1.52 0.75 0.38 0.22 0.12 0.05 4.78 3.80 3.06 2.52 2.13 1.56 1.19 0.94 0.76 0.53

9 5.2 3.3 2.1 1.1 0.54 0.3 0.16 0.06 0.03 4.61 3.76 3.07 2.59 1.89 1.45 0.15 0.93 0.65 0.48 10 6 3.8 2.5 1.3 0.62 0.35 0.19 0.075 0.035 5.05 4.08 3.37 2.84 2.08 1.65 1.26 1.02 0,71 0.52

7.3 4.5 3 1.5 0.75 0.42 0.23 0.08 0.04 4.43 3.65 3.08 2.26 1.73 1.36 1.11 0.77 0.56 8 5.4 3.4 1.7 0.85 0.48 0.26 0.1 0.047 4.76 3.95 3.31 2.43 1.86 1.47 1.19 0.83 0.61 9 5.8 3.75 1.9 0.96 0.53 0.29 0.11 0.053 5.1 4.22 3.54 2.60 2.00 1.57 1.27 0.88 0.65

6.5 4.3 2.1 1.1 0.6 0.32 0.12 0.06 4.49 3.78 2.77 2.13 1.68 1.36 0.95 0.70 7.2 4.6 2.45 1.2 0.67 0.35 0.14 0.065 0.033 4.76 4.01 2.94 2.26 1.78 1.44 1.00 0.77 0.54

5.4 2.8 1.4 0.78 0.43 0.16 0.073 0.037 4.26 3.12 2.38 1.86 1.53 1.06 0.78 0.57 6 3.2 1.53 0.86 0.46 0.175 0.08 0.043 0.037 4.49 3.29 2.53 1.99 1.65 1.12 0.84 0.61 0.52 6.5 3.4 1.7 0.93 0.5 0.19 0.09 0.046 0.04 0.025 4.72 3.45 2.68 2.12 1.72 1.23 0.88 0.63 0.54 0.4

12.2 7.4 4.3 2.7 1.7 0.9 0.45 0.25 0.13 0.055 0.024 5.30 4.20 3.40 2.81 2.36 1.73 1.34 1.06 0.86 0.61 0.44

1.6 6.2 3.5 2 1.3 0.82 0.41 0.21 0.12 0.07 0.03 4.86 3.72 2.94 2.37 1.96 1.64 1.22 0.94 0.76 0.59 0.41

24 14 8 2.76 1 0.49 0.24 0.14 0.084.17 3.31 2.68 1.72 1.18 0.87 0.67 0.53 0.43

25 12 6.3 3.5 2 0.75 0.3 0.14 0.07 3.58 2.63 2 1.58 1.28 0.82 0.57 0.42 0.32

INSIDE DIAMETER (mm)

If is possible to approximate the pressure losses caused

by the accessories with the following comparisons:

Bottom valve: like 15 m piping

Check valve: like 10 m piping

On/off valve: like 5 m piping

Bends and elbows: like 5 m piping

For piping other than new piping in cast iron, multiply

the figures in the table by the following coefficients:

67,0:leets sselniatS

67,0:CVP

08,0:yalC

08,0:leets delloR

71,1:leets dezinavlaG

Slightly rusted pipes: 2,10

Highly encrusted rusted pipes: 3,60

PRESSURE DROP TABLE

Reference

134 135

NET POSITIVE SUCTION HEAD (NPSH)

Reference

Net Positive Suction Head (NPSHR)NPSHR is dependent upon the pump design and is determined by the pump manufacturer. NPSHR is an important value which greatly contributes to the successful operation of a centrifugal pump. It is the amount of positive head in metre of liquid absolute required at the pump suction to prevent vaporization or cavitation of the fluid. NPSHR values usually vary with pump capacity and are based on clear water with a specific gravity of 1.0.

Net Positive Suction Head Available (NPSHA)NPSHA is dependent upon the system in which the pump operates. NPSHA is the amount of head or pressure that is available to prevent vaporization or cavitation of the fluid in the system. It is the amount of head available above the vapor pressure of the liquid at a specified temperature and is measured in metre of liquid absolute .

NPSHA = (P1 - Pv) x 2.31Sp. Gr.

+ Z1 - Hfs

WhereP1 : Absolute pressure on liquid surface in psia.

Absolute pressure is equal to gauge reading plus atmospheric pressure.Three common examples are:1. Open tank - No gage reading so absolute pressure equals atmospheric pressure or

14.7 psia at sea level.2. Closed tank under pressure - Add gage reading in psi to atmospheric pressure to

get total absolute pressure.3. Closed tank under vacuum - Subtract vacuum reading in inches of mercury from

atmospheric pressure in inches of mercury (30 inches at sea level) and convert to psia by multiplying by .49.

P1 = (30 - Vacuum) x .49

Pv : Vapor pressure of liquid in psia at pump temperature.Z1 : Height of liquid surface above pump suction, measured in ft. If surface is below pump,

use minus sign.Hfs : Friction loss in ft of liquid in suction pipe including entrance loss from tank to pipe,

and losses in all valves, elbows and other fittings.Sp.Gr. : Specific gravity of liquid being handled.

NPSHA vs. NPSHRTo prevent vaporization or cavitation of the liquid in the suction side of the pump and to ensure rated pumpperformance, NPSHA must be greater or equal to the NPSHR.

That is : NPSHA NPSHR

12