Units of
Measure
Chapter
29
Introduction to Units of Measure ...................................................... 29-3
Units of Measure
Length, Area, Volume ....................................................................... 29-5
Mass, Mass per Length, Mass per Volume ....................................... 29-6
Pressure, Velocity ............................................................................. 29-7
Flow Rates ......................................................................................... 29-8
Electric, Power .................................................................................. 29-9
Viscosity, Angular, Other.................................................................. 29-10
Miscellaneous Useful Constants ........................................................ 29-10
Project Specifications and their Use of Units of Measure
Special Units of Measure .................................................................. 29-11
Length and Area Units ...................................................................... 29-11
Volume Units .................................................................................... 29-13
Mass and Unit Mass .......................................................................... 29-14
Pressure Units ................................................................................... 29-15
Velocity and Flow Rate Units ........................................................... 29-15
Electrical Units .................................................................................. 29-17
Power Units ....................................................................................... 29-18
Viscosity Units .................................................................................. 29-18
G1 © ICARUS Corporation, 1998.
29-2 ICARUS Reference
© ICARUS Corporation, 1998. G1
Chapter 29: Units of Measure
29-3
Introduction to Units of Measure
ICARUS systems provide a choice of two sets of units of measure:
• I-P (Inch-Pound)
• METRIC (Metric).
The user must select the desired set indirectly (by specifying the country base location) or directly. Once the
appropriate set is selected, the user may wish to redefine one or more variables from the base units of measure to
some other measure. The Units of Measure Data provides the means of identifying the conversion.
The user should refer to units of measure later in this chapter for the basic definitions of variables and their
associated units of measure for I-P and METRIC sets. Along with these definitions are conversion multipliers
for relating I-P to METRIC units. Each line bearing a two-digit Type Number is a candidate for user
redefinition. The type number is used to identify the specific unit of measure to be redefined. The user would
then provide a new name for that unit of measure and the appropriate conversion multiplier to convert from the
base unit of measure to the desired unit of measure.
The following special units of measure are not characterized by a Type Number and simple conversion
multiplier:
• Temperature - User may define temperature to be in DEG C, DEG F or DEG K.
• Process Pipe Size (diameter and thickness dimensions only) - User may specify process pipe to be designed
in INCH or MM units of measure, independently of other linear units of measure.
• Driver Power - User may specify drivers to be specified, sized, selected, reported in HP or KW.
Notes of Caution
All user-provided numeric values for dimensions, sizes, extents, intensities, flows, etc., are considered by the
system to conform to those units of measure selected and/or defined by the user. It is the user’s responsibility to
be constantly aware of the units of measure so selected throughout the entire exercise of preparing project data
for the system. The user is cautioned that variable redefinition from system base to a user unit of measure could
have unpredictable downstream effects, for example, in selection of plates, wire, tubing, pipe, etc. Further, the
user is cautioned that each base set of units, I-P and METRIC, has its own special set of default values; the pair
of default values are not necessarily related to one another by usual conversion relationships; each is established
by itself as a reasonable value in the base unit of measure. Once the user’s set of units of measure is established,
default values are evaluated as follows:
• Unit of Measure Conversion: are used to convert the base unit of measure default value by the user’s
numeric value to obtain the value of the revised default value in the desired units of measure.
• No Unit of Measure Conversion: the system uses the default value as tabulated.
G1 © ICARUS Corporation, 1998.
29-4 ICARUS Reference
Example
• METRIC base set selected in Project Title Data, and
• Unit of measure data used to convert pressure in KPA (METRIC) to PSIG using 0.14504 = 1/6.894757 as
conversion for Type No. 18.
• Turbine steam pressure METRIC default is 2000 KPA, which, converted to PSIG, is 290.047549 PSIG.
The PSIG value is used in sizing the turbine if the user does not enter the pressure value.
• Contrast this value with the I-P default value printed in the turbine table as 300 PSIG.
Another Example
The METRIC base user will have all length variables defined in terms of millimeters, meters, etc. As a
consequence, pipe sizes (diameters) and wall thicknesses will be expected to be specified, sized, selected and
reported in MM. Should the METRIC base user desire pipe to be specified, sized, selected and reported in MM.
Should the METRIC base user desire pipe to be specified, sized, selected and reported as INCH values, the user
must enter the designator INCH in the field labelled Pipe Size.
This note of caution is tendered for temperature and driver power a well as pipe sizing.
Final Note of Caution
The User of this section should exercise extreme care and deliberation in redefining units of measure. Since,
once established:
• All user input is expected in the defined units of measure.
• Default values subject to conversions will not be in rounded numbers but will be conversions from base
default values.
• Selection and design criteria may be impacted and affected by user redefinition of units of measure.
• All reporting by the system will conform to the selected units of measure.
• The trial of consequences of redefinitions of the units of measure is one expectedly difficult to backtrack,
especially if that variable affects size selection of materials in a non-standard way.
© ICARUS Corporation, 1998. G1
Chapter 29: Units of Measure
Units of Measure
Type Inch-Pound
No.
Description
Metric
Conversion
Symbol
Description
Symbol
Length
01
Inches
INCHES
x 25.4
= Millimeters
MM
02
Feet
FEET
x 0.3048
= Meters
M
03
Miles (statute)
MILES
x 1.60934
= Kilometers
KM
04
Mesh
MESH
x 1.0000
= Mesh
MESH
05
Square feet
SF
x 0.092903
= Square meters
M2
06
Square yards
SY
x 0.836127
= Square meters
M2
Area
Volume
07
Cubic feet
CF
x 0.028317
= Cubic meters
M3
08
Cubic yards
CY
x 0.76455
= Cubic meters
M3
09
Gallons
(231 cubic inches)
GALLONS
x 0.00378541
= Cubic meters
M3
10
Barrels (42 gallons)
BARRELS
x 0.1589873
= Cubic meters
M3
11
Bags
(94 pounds)
BAGS
x 0.852749
= Bags
(50 kilograms)
BAG-50KG
48
Board feet
BDFT
x 0.0023597
= Cubic meters
M3
G1 © ICARUS Corporation, 1998.
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29-6 ICARUS Reference
Type Inch-Pound
No.
Description
Metric
Conversion
Symbol
Description
Symbol
Mass
12
Pounds
LBS
x 0.45359
= Kilograms
KG
13
Tons (2000 pounds)
TONS
x 0.907185
= 1000 Kilograms
TON
Mass per Length
14
Pounds per foot
LB/FT
x 1.488156
= Kilograms/meter
KG/M
15
Pounds per yard
LB/YD
x 0.496052
= Kilograms/meter
KG/M
Mass per Volume
16
Pounds per
batch
LB/BATCH x 0.45359
= Kilograms
per batch
KG/BATCH
17
Pounds per
cubic foot
PCF
= Kilograms per
cubic meter
KG/M3
x 16.01829
© ICARUS Corporation, 1998. G1
Chapter 29: Units of Measure
Type Inch-Pound
No.
Description
Metric
Conversion
Symbol
Description
Symbol
Pressure
18
Pounds (force)
per square
inch, gauge
PSIG
x 6.894757
= Kilopascals
(1000 newtons
per square
meter)
KPA
19
Inches of mercury
IN HG
x 3.38638
= Kilopascals
KPA
(1000 newtons
per square meter)
20
Inches of water
IN H2O
x 249.082
= Pascals
PA
21
Millimeters of
mercury (TORR)
MM HG
x 133.322
= Pascals
PA
22
Pounds (force)
per square
foot (loading)
PSF
x 0.0478802
= Kilonewtons
per square
meter (1
newton = 1 kg
mass under
1 meter/sec2
acceleration)
KN/M2
Velocity
23
Feet per minute
FPM
x 18.2880
= Meters/hour
M/H
24
Miles per hour
MPH
x 1.60934
= Kilometers/hour
KM/H
25
Revolutions
per minute
RPM
x 1.00000
= Revolutions
per minute
RPM
na
Cycles per second
HZ
x 1.00000
= Hertz
HZ
(NOTE: HZ is frequently used to refer to local power frequency)
G1 © ICARUS Corporation, 1998.
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29-8 ICARUS Reference
Type Inch-Pound
No.
Description
Metric
Conversion
Symbol
Description
Symbol
Flow Rates
26
Cubic feet
per minute
CFM
x 1.69901
= Cubic meters
per hour
M3/H
27
Cubic feet
per hour
CFH
x 0.028317
= Cubic meters
per hour
M3/H
28
Cubic feet per
minute per
square foot
of surface
CFM/SF
x 18.28800
= Cubic meters
per hour per
square meter
of surface
M3/H/M2
29
Gallons per minute
GPM
x 0.063090
= Liters per second
L/S
30
Gallons per hour
GPH
x 0.003785
= Cubic meters per
hour
M3/H
31
Pounds per hour
LB/H
x 0.45359
= Kilogram/hour
KG/H
32
Tons per hour
TPH
x 0.907185
= Tons per hour
TON/H
33
Tons per day
TPD
x 0.037799
= Tons per hour
TON/H
© ICARUS Corporation, 1998. G1
Chapter 29: Units of Measure
Type Inch-Pound
No.
Description
Metric
Conversion
Symbol
Description
Symbol
Electric
34
Volts
V
x 1.0
= Volts
V
35
Kilovolts (1000 v)
KV
x 1.0
= Kilovolts
KV
36
Amperes
A
x 1.0
= Amperes
A
37
Kiloamperes (1000 a)
KA
x 1.0
= Kiloamperes
KA
38
Watts
W
x 1.0
= Watts
W
39
Kilowatts (1000 w)
KW
x 1.0
= Kilowatts
KW
40
Kilovoltamperes (1000 v-a)
KVA
x 1.0
= Kilovoltamperes
KVA
Power
na
Horsepower
HP
x 0.74570
= Kilowatts
KW
41
Tons, refrigeration
(12000 Btu/hr)
TONS-REF x 3.51685
= Kilowatts
KW
42
Btu per hour
BTU/H
x 0.293071
= Watts
W
43
Millions of Btu per hour
MMBTU/H
x 0.293071
= Megawatts
MEGAW
44
Btu per hour per
square foot
BTU/H/SF
x 3.15460
= Watts per
square meter
W/M2
45
Btu per pound
BTU/LB
x 2.32601
= Kilojoules
per kilogram
KJ/KG
G1 © ICARUS Corporation, 1998.
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29-10 ICARUS Reference
Type Inch-Pound
No.
Description
Metric
Conversion
Symbol
Description
Symbol
Viscosity
46
Centipoise
CPOISE
x 1.0
= Millipascal
-seconds
MPA-S
47
Centistoke
CSTOKE
x 1.0
= Millimeters
squared
per second
MM2/S
DEGREE
x 1.0
= Degrees
DEGREE
Angular
na
Degrees
Other
na
Fahrenheit
temperature
DEG F
(F-32)/1.8
= Celsius
temperature
DEG C
na
Fahrenheit
temperature
difference
DEG F
x 0.55555
= Celsius
temperature
difference
DEG C
na
Nominal pipe size
(diameter and
thickness)
INCH
not applicable size
Nominal pipe
(diameter and
thickness)
MM
na
Driver power
HP
not applicable
Driver power
KW
Miscellaneous Useful Constants
1. Gravitational Constant:
Inch-Pound
Metric
32.174 lb-ft/lb(force)-sec2
9.80665 kg-m/kg(force)-sec2
2. Absolute temperatures:
Rankine
Kelvin
DEG R = 459.67 + DEG F
DEG K = 273.15 + DEG C
3. Gas Constant, R (basis: 22.4140 liters at 0 degrees C, 1 atm. for the volume of 1 gram-mole of gas and
PV=ZnRT)
R = 10.732 psia-ft3/lb-mole degrees R
R = 8.3145 KPA-m3/kg-mole degrees K
© ICARUS Corporation, 1998. G1
Chapter 29: Units of Measure 29-11
Project Specifications and their Use of Units of Measure
Special Units of Measure
Unit of Measure Name for Temperature: F (INCH-POUND) or C or K (METRIC)
Use to specify:
All items specifying temperature
Unit of Measure Name for pipe size: INCH (INCH-POUND) or MM (METRIC)
Use to specify:
Pipe, valves, fittings
Unit of Measure Name for driver power: HP (INCH-POUND) or KW (METRIC)
Use to specify:
Electric motors, turbines
Length and Area Units
Unit of Measure Name for: INCHES (INCH-POUND) or MM (METRIC)
Use to specify:
Vessel components wall/plate thickness
tube diameter
cladding thickness
Conveyor belts - width
Conveyors/vibrating - width of pan
Centrifuge bowl/basket diameter
Dryers, pan type - depth
Dust collectors, cyclone diameter
Filters, plate/frame size
Feeders, rotary - diameter
vibrating - width
Heat exchangers, shell diameter
Mills, product, feed size
Reboilers, port area
Stacks - diameter
Towers - tray spacing
Insulation thickness
Manhole diameter
Steel, walkway width
Vibrating screens - sifter screen diameter
G1 © ICARUS Corporation, 1998.
29-12 ICARUS Reference
Length and Area Units (continued)
Unit of Measure Name for: FEET (INCH-POUND) or M (METRIC)
Use to specify:
Vessel size span, length, height, diameter,
tube length
Fluid head- pumps
Unit of Measure Name for: MILES (INCH-POUND) or KM (METRIC)
Use to specify:
Site development
Unit of Measure Name for: MESH (INCH-POUND) or MESH (METRIC)
Use to specify:
Crushers
Filter, tubular
Unit of Measure Name for: SF (INCH-POUND) or M2 (METRIC)
Use to specify:
Dryers - tray surface area
Dust collectors - cloth area
Drum dryers - peripheral area
Evaporators - heated surface area
Flakers - area
Heat exchangers
Linings
Rotary dryers
Tray drying systems, tray surface
Vibrating screen
Unit of Measure Name for: SY (INCH-POUND) or M2 (METRIC)
Use to specify:
Site development
© ICARUS Corporation, 1998. G1
Chapter 29: Units of Measure 29-13
Volume Units
Unit of Measure Name for: CF (INCH-POUND) or M3 (METRIC)
Use to specify:
Centrifuges - capacity
Filters, plate/frame capacity
Mixers
Rotary dryers, working capacity
Vertical tanks, gas holders, live bottom
Unit of Measure Name for: CY (INCH-POUND) or M3 (METRIC)
Use to specify:
Site development
Unit of Measure Name for: GALLONS (INCH-POUND) or M3 (METRIC)
Use to specify:
Vessel volume, liquids
Kneaders
Packings
Vertical tanks
Unit of Measure Name for: BARRELS (INCH-POUND) or M3 (METRIC)
Use to specify:
Vertical tanks
Unit of Measure Name for: BAGS (INCH-POUND) or BAGS-50KG (METRIC)
Use to specify:
Field-mixed concrete components
Unit of Measure Name for: BD FT (INCH-POUND) or M3 (METRIC)
Use to specify:
Foundation formwork (shuttering)
G1 © ICARUS Corporation, 1998.
29-14 ICARUS Reference
Mass and Unit Mass
Unit of Measure Name for: LBS (INCH-POUND) or KG (METRIC)
Use to specify:
Cranes
Scales
Unit of Measure Name for: TONS (INCH-POUND) or TON (METRIC)
Use to specify:
Elevators
Cranes, hoists
Unit of Measure Name for: LB/FT (INCH-POUND) or KG/M (METRIC)
Use to specify:
Steel member sizes
Pile sizes
Unit of Measure Name for: LB/YD (INCH-POUND) or KG/M (METRIC)
Use to specify:
Site development - railroad rails
Unit of Measure Name for: LB/BATCH (INCH-POUND) or KG/BATCH (METRIC)
Use to specify:
Centrifuges, batch type
Filters
Unit of Measure Name for: PCF (INCH-POUND) or KG/M3 (METRIC)
Use to specify:
Density of solids, fluids
Blenders
© ICARUS Corporation, 1998. G1
Chapter 29: Units of Measure 29-15
Pressure Units
Unit of Measure Name for: PSIG (INCH-POUND) or KPA (METRIC)
Use to specify:
Gauge pressure
Unit of Measure Name for: IN HG (INCH-POUND) or KPA (METRIC)
Use to specify:
Vacuum pumps
Unit of Measure Name for: IN H2O (INCH-POUND) or PA (METRIC)
Use to specify:
Draft pressure measurement, ductwork
Dust collector, cyclone - pressure drop
Unit of Measure Name for: MM HG (INCH-POUND) or PA (METRIC)
Use to specify:
Ejectors, absolute pressure
Vacuum pumps, absolute pressure
Unit of Measure Name for: PSF (INCH-POUND) or KN/M2 (METRIC)
Use to specify:
Civil - soil bearing capacity
Velocity and Flow Rate Units
Unit of Measure Name for: FPM (INCH-POUND) or M/H (METRIC)
Use to specify:
Conveyors, belt speed
Unit of Measure Name for: MPH (INCH-POUND) or KM/H (METRIC)
Use to specify:
Wind velocity
Unit of Measure Name for: RPM (INCH-POUND) or RPM (METRIC)
Use to specify:
Agitators, agitated tanks
Motors
Blenders
Unit of Measure Name for: CFM (INCH-POUND) or M3/H (METRIC)
Use to specify:
Air, gas compressors
Air dryers
Dust collectors, washers, precipitators, cyclone
Fans
Vacuum pumps
Unit of Measure Name for: CFH (INCH-POUND) or M3/H (METRIC)
Use to specify:
Feeders
G1 © ICARUS Corporation, 1998.
29-16 ICARUS Reference
Velocity and Flow Rate Units (continued)
Unit of Measure Name for: CFM/SF (INCH-POUND) or M3/H/M2 (METRIC)
Use to specify:
Dust collectors
Unit of Measure Name for: GPM (INCH-POUND) or L/S (METRIC)
Use to specify:
Centrifugal pumps
Barometric condenser - water flow rate
Filter, cartridge, tubular
Gear pumps
Positive displacement pumps
Towers, cooling
Water treatment systems
Unit of Measure Name for: GPH (INCH-POUND) or M3/H (METRIC)
Use to specify:
Water treatment systems
Unit of Measure Name for: LB/H (INCH-POUND) or KG/H (METRIC)
Use to specify:
Dryers, evaporative capacity
Drum dryers
Evaporators
Ejectors - air flow rate
Filters
Feeders
Flakers, drum type
Heat exchangers
Reactors
Rotary dryers
Tray drying systems
Towers, packed, trayed
Water treatment systems - boilers
Wiped film evaporators
Unit of Measure Name for: TPH (INCH-POUND) or TON/H (METRIC)
Use to specify:
Conveyors
Bucket conveyors
Crushers
Feeders
Filters
Mills
Unit of Measure Name for: TPD (INCH-POUND) or TON/H (METRIC)
Use to specify:
Crystallizers
Feeder, vibrating
Mills
© ICARUS Corporation, 1998. G1
Chapter 29: Units of Measure 29-17
Electrical Units
Unit of Measure Name for: V (INCH-POUND) or V (METRIC)
Use to specify:
Electrical plant bulks
Unit of Measure Name for: KV (INCH-POUND) or KV (METRIC)
Use to specify:
Electrical plant bulks
Unit of Measure Name for: A (INCH-POUND) or A (METRIC)
Use to specify:
Electrical plant bulks
Unit of Measure Name for: KA (INCH-POUND) or KA (METRIC)
Use to specify:
Electrical plant bulks
Unit of Measure Name for: W (INCH-POUND) or W (METRIC)
Use to specify:
Electrical plant bulks
Unit of Measure Name for: KW (INCH-POUND) or KW (METRIC)
Use to specify:
Electric generators, portable
Heat exchangers - tank heaters
Unit of Measure Name for: KVA (INCH-POUND) or KVA (METRIC)
Use to specify:
Electric generators
Electrical substation equipment
G1 © ICARUS Corporation, 1998.
29-18 ICARUS Reference
Power Units
Unit of Measure Name for: TONS-REF (INCH-POUND) or KW (METRIC)
Use to specify:
Refrigeration units
Unit of Measure Name for: BTU/H (INCH-POUND) or W (METRIC)
Use to specify:
Heat transfer rate
Unit of Measure Name for: MMBTU/H (INCH-POUND) or MEGAW (METRIC)
Use to specify:
Furnaces
Heating units
Reboilers
Unit of Measure Name for: BTU/H/SF (INCH-POUND) or W/M2 (METRIC)
Use to specify:
Flarestacks
Unit of Measure Name for: BTU/LB (INCH-POUND) or KJ/KG (METRIC)
Use to specify:
Reboilers
Flarestacks
Viscosity Units
Unit of Measure Name for: CPOISE (INCH-POUND) or MPA-S (METRIC)
Use to specify:
Pumps
Agitated vessels
Unit of Measure Name for: CSTOKE (INCH-POUND) or MM2/S (METRIC)
Use to specify:
Pumps, gear
© ICARUS Corporation, 1998. G1