Pipe Absolute Roughness and Hazen-Williams C
Source:
*   "Flow of Fluid through Valves, Fittings, and Pipes", Technical Paper No. 410, Crane Co., New York, 1985.
**  "Piping Handbook", Nayyar, Mohinder L., Editor in Chief, Sixth Ed., McGraw-Hill, Inc., New York, 1992.
 

 

 

Recommended

Absolute Roughness

Hazen-Williams C

Pipe or Tubing Material

feet

inches

Nominal value when new

Drawn Tubing

0.000 005 *

0.000 06

140

Teflon, PTFE; PFA-PTFE

0.000 005

0.000 06

   140 **

High Density Polyethylene, PVDF; PVC; etc

0.000 07

0.000 84

   140 **

Epoxy Coated Steel

0.000 025

0.000 3

140

New API Line Pipe

0.000 0582

0.000 7

140

Commercial Steel

0.000 15 *

0.001 8

   140 **

Stainless Steel

0.000 15

0.001 8

   140 **

Asphalt Coated Cast Iron

0.000 4 *

0.004 8

140

Galvanized Iron

0.000 5 *

0.006

130

Cast Iron

0.000 85 *

0.010 2

   120 **

Wood Stave

0.003 to 0.000 6 *

0.036 to 0.0072

120

Concrete

0.01 to 0.001 *

0.12 to 0.012

130 to 120

Riveted Steel

0.03 to 0.003 *

0.36 to 0.036

110

 PTFE= poly(tetrafluoroethylene)

PFA=poly(fluoroalkoxy)

PVC=poly(vinyl chloride)

PVDF=poly(vinylidene fluoride)

 

 

 

Darcy Friction Factor at Complete Turbulence

New Commercial Steel Pipe

Source:  "Flow of Fluid through Valves, Fittings, and Pipes", Technical Paper No. 410, Crane Co., New York, 1985.

 

Nominal Size

1/2"

3/4"

1"

1-1/4"

1-1/2"

2"

2-1/2" to 3"

4"

5"

6"

8" to 10"

12" to 16"

18" to 24"

Darcy Friction Factor

0.027

0.025

0.023

0.022

0.021

0.019

0.018

0.017

0.016

0.015

0.014

0.013

0.012

 

  Basic or Typical Unit Conversions

(Basic unit conversions are in Bold)

 

Length or Distance

1

Angstrom = 10-10 m
1 micron = 10-6 m
1 mil = 10-3 inch (for corrosion measurement)
1 mil = 25.4 micron
1 inch = 2.54 cm
         
1 inch = 25.4 mm
1 ft = 0.3048 m
1 ft = 304.8 mm
3.28084 ft = 1 m
1 mile (Statute) = 1.6093 km
         
1 mile (Statute) = 5,280 ft
1.1516 mile (Statute) = 1 mile (Nautical)
1 nm, nanometer = 10-9 m

Area

1 acre = 43,560 ft2
1 hectare = 10,000 m2
1 acre = 0.40469 hectare
1 acre = 4046.9 m2

Volume

35.3147 ft3 = 1 m3
6.2898 barrel = 1 m3
1 liter = 0.001 m3
1 liter = 1,000 cm3
1 barrel = 42 US gallon
         
231 inch3 = 1 US gallon
4 quart = 1 US gallon
3.78533 liter = 1 US gallon
1.20095 US gallon = 1 Imperial gallon
1 ft3 = 7.48052 US gallon
         
32 fluid oz = 1 quart
37.3245 scf (1 atm, 60oF) = 1 Nm3 (1 atm, 0oC)
1 acre-ft = 43,560 ft3

 

Velocity

1 fps or ft/sec = 0.3048 m/s
1 fps or ft/sec = 0.68182 mph or mile/hr
1 fps or ft/sec = 1.097 km/h
1 knot (nau. mile/hr) = 1.852 km/h

 

Volumetric flow

1 cfm or ft3/min. = 1.699 m3/h
4.4029 US gpm = 1 m3/h
1 MMcfd or 106cfd = 1179.9 m3/h
35.3147 Bcfy or 109cfy = 1 Bm3/y
1,000 bpd or barrel/day = 6.6244 m3/h
         
1 bpd or barrel/day = 1.75 USgph or USgal/hr
1 bpd or barrel/day = 0.0292 USgpm or USgal/min
1 USgpm or USgal/min = 3.7854 lpm or liter/min
1.20095 USgpm or USgal/min = 1 Imperial (UK) gpm
1 USgpm or USgal/min = 5451 liter/day
         
24,000 liter/day = 1 m3/h
1 liter/min = 0.06 m3/h
1 liter/s = 3.6 m3/h

 

Mass

2.20462262 lb = 1 kg
2,000 lb = 1 short ton or net ton
2,240 lb = 1 long ton or gross ton
2204.62262 lb = 1 metric ton or tonne
1 lb = 7,000 grain
         
1,000 kg = 1 metric ton or tonne
1 long ton = 1.12 short ton

 

Density

62.428 lb/ft3 = 1 g/cm3 or g/cc
62.428 lb/ft3 = 1,000 kg/m3
1 metric tom/m3 = 1 g/cm3 or g/cc
1,000 kg/m3 = 1 g/cm3 or g/cc

 

Specific Gravity

1 Sp. Gr. (water = 1) = 0.999051 g/cm3 (@60oF)
1 Sp. Gr. (water = 1) = 62.3688 lb/ft3 (@60oF)
1 Sp. Gr. (air = 1) = 0.00122 g/cm3 (@60oF)
1 Sp. Gr. (air = 1) = 0.0764 lb/ft3 (@60oF)

 

Mass/Volumetric Flow Rate

1 bpd (@ 1 Sp. Gr.) = 0.159 tonne/day
17,232 bpd (@ 1 Sp. Gr.) = 1,000,000 tonne/year (@ 365 days/yr.)
1 USgpm (@ 1 Sp. Gr.) = 500.76 lb/hr

 

Pressure

1 bar = 1,000,000 dyne/cm2
1 bar = 100,000 Pa or Pascal
1 bar = 100,000 Newton/m2
1 bar = 100 kPa
10 bar = 1 MPa
         
1.01325 bar = 1 atm
1 Pa or Pascal = 1 Newton/m2
1 Pa or Pascal = 10 dyne/cm2
133.32 Pa or Pascal = 1 torr
1.01325x106 dyne/cm2 = 1 atm
         
1.0332 kg/cm2 = 1 atm
33.9 ft H2O @ 39.2oF = 1 atm
10.332 m H2O @ 39.2oF = 1 atm
10332 mm H2O @ 39.2oF = 1 atm
14.6959 psi = 1 atm
         
14.5037 psi = 1 bar
0.0145037 psi = 1 mbar
14.2232 psi = 1 kg/cm2
0.145037 psi = 1 kPa
1 psi = 6.8947 kPa
         
145.037 psi = 1 Mpa
1 psi = 2.3 ft H2O @ 39.2oF
1 psi = 27.673 inch H2O @ 39.2oF
1 psi = 2.036 inch Hg @ 32oF
0.1 psi = 5.1715 mm Hg @ 0oC
         
14.6959 psi = 760 mm Hg @ 0oC
1 torr = 1 mm Hg @ 0oC
760 torr = 1 atm
1 psi/1000ft = 2.2621 kPa/100m
10 Pa/m = 1 kPa/100m

 

Temperature Difference

1.8 oF = 1 oC
1.8 oR = 1 oK
1.0 oK = 1 oC
1.0 oR = 1 oF

 

Viscosity

0.01 poise = 1 cP or centipoise
0.01 (dyne)(sec)/cm2 = 1 cP or centipoise
0.000672 lb/ft/sec = 1 cP or centipoise
2.42 lb/ft/hr = 1 cP or centipoise
3.6 kg/m/h = 1 cP or centipoise
         
0.01 g/cm/s = 1 cP or centipoise
0.001 g/mm/s = 1 cP or centipoise
1 cSt or centistoke = 0.01 St or stoke
1 cSt or centistoke = 1 mm2/s
1 cSt or centistoke = 0.01 cm2/s
         
1 cSt or centistoke = 0.000001 (=10-6) m2/s
1 cSt or centistoke = 0.00001076 ft2/sec
0.001076 ft2/sec = 1 cm2/s
1 (Pa)(s) = 1,000 cP or centipoise
1 (mPa)(s) = 1 cP or centipoise
         
14.5037x10-8 (psi)(sec) = 1 cP or centipoise
1 (dyne)(sec)/cm2 = 1 poise

 

Heat, Work, or Energy

1 (Newton)(m) = 1 J or Joule
1 cal Thermalchemical = 4.184 J or Joule
252 cal Thermalchemical = 1 Btu International Table
1 kWh = 3412.2 Btu International Table
1 kWh = 860 kcal
         
1 kWh = 3600 kJ
1 therm = 100,000 (=105) Btu
1055.05585262 J or Joule = 1 Btu International Table
1 cal International Table = 4.1868 J or Joule

 

Heat Content

1 Btu/lb International Table = 2.326 kJ/kg
1 Btu/lb International Table = 0.5559 kcal/kg Thermalchemical
1 Btu/scf International Table = 39.3807 kJ/Nm3

 

Surface Tension

0.88x10-7 Btu/ft2 = 1 dyne/cm
0.0000688523 lbf/ft = 1 dyne/cm
0.001 Newton/m = 1 dyne/cm

 

Heat Capacity

1 Btu/lbmol/oF International Table = 1.000669 kcal/kgmol/oC Thermalchemical
1 Btu/lbmol/oF International Table = 1.000669 cal/gmol/oC Thermalchemical
1 Btu/lb/oF International Table = 1.000669 kcal/kg/oC Thermalchemical
1 Btu/lb/oF International Table = 1.000669 cal/g/oC Thermalchemical
1 Btu/lb/oF International Table = 1.163 Wh/kg/oC
         
1 Btu/lb/oF International Table = 4.1868 kJ/kg/oC

 

Heat Flux

100 Btu/hr/ft2 International Table = 271.2 kcal/h/m2 Thermalchemical
100 Btu/hr/ft2 International Table = 315.4 W/m2

 

Heat Transfer Coefficient

100 Btu/hr/ft2/oF International Table = 488.57 kcal/h/m2/oC Thermalchemical
100 Btu/hr/ft2/oF International Table = 567.8 W/m2/oC

 

Fouling Resistance

0.001 (hr)(ft2)(oF)/Btu  International Table

=

0.000208 (h)(m2)/(oC)/kcal Thermalchemical

 

Power, Heat Flow, or Duty

1 mech. hp = 0.7457 kW
1 mech. hp = 2544.5 Btu/hr  International Table
1 mech. hp = 550 ft-lbf/sec
1 Watt = 1 J/s
1 kW = 3,600,000 J/h
         
1 kW = 3,600 kW/h
1 kW = 3412.2 Btu/hr  International Table
1,341 mech, hp = 1 MW or Mega Watt
1 MM (106) Btu/hr = 1.055 GJ/h or Giga (109) J/h
1.05505585262 kJ/h = 1 Btu/hr International Table
         
0.252 kcal/h Thermalchemical = 1 Btu/hr International Table
1 kcal/h Thermalchemical = 3.9683 Btu/hr International Table
1 ton refrigeration = 3.5168 kW
1 ton refrigeration = 12,000 Btu/hr International Table

 

Thermal Conductivity

1 Btu/hr/ft2/(oF/ft) = 1.488 kcal/h/m2/(oC/m)
1 Btu/hr/ft2/(oF/ft) = 12 Btu/hr/ft2/(oF/inch)
1 Btu/hr/ft2/(oF/ft) = 1.73 W/m/oC

 

Gas Molar Volume

1 lb mole = 379.5 scf (1 atm, 60oF)
1 lb mole = 359 ft3 (1 atm, 32oF)
1 g mole = 22.414 liter (1 atm, 0oC)
1 kg mole = 22.414 Nm3 (1 atm, 0oC)

 

 

 

Newtonian Incompressible Isothermal Flow

 

Non-Newtonian Fluids

Although in actuality many non-Newtonian fluids are formed with multiphase mixtures, such as slurries or liquid-liquid dispersions, they can be treated as a single phase homogeneous flow from a fluid mechanics viewpoint.  For the purpose of presenting a computer-aided engineering design tool for practicing engineers to handle fluid hydraulics as part of their effort in equipment sizing, the non-Newtonian fluids covered here are considered as homogeneous with their respective flow behavior.  Common rheological models that are used to approximate the flow behavior include:

Model Characteristics Typical systems that model had applied
Bingham plastic Newtonian with yield stress fine suspensions, pastes, paint systems or some asphalts
Power law shear-thinning suspensions of high solid concentrations
Yield-power Law shear-thinning with yield stress clay water suspensions, drilling mud slurries, or cement slurries of various compositions

 

Rheological Models for Non-Newtonian Fluids

Bingham Plastic Model

Power Law  Model

Yield-Power Law  Model

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