www.m&hem1.com Standard Line Sizing Spreadsheet For Liquids
Introduction This spreadsheet can be used to calculate pressure drops in liquid lines, taking account fittings (such as bends, valves and other equipment items). The spreadsheet is split into the following sections -
A "ow to !se This alculation" #orksheet The $ressure %rop alculation alculation #orksheet itself - marked "alculation" "alculation" A Theor& #orksheet which which presents the equations used in the calculation.
't is recommended that the user first reads the ow to !se These alculation worksheet before starting a calculation.
Revision ev. * 'nitial issu ssue ev. *A osmetic changes onl& (spell checking / revised disclaimer)
*+-ct -ct-- *0-%ec-
Disclaimer: This calculation provides an estimate for estimating pressure drops in liquid liquid pipelines. #e cannot be held responsible for its use. As with all areas of process engineering, calculations calculations should be checked b& a competent engineer.
www.m&hem1.com
Standard Line Sizing Spreadsheet For Liquids
evision *A
HOW TO S! THIS "#L"L#TIO$ %&'
Introduction
This spreadsheet can be used to calculate pressure drops in pipelines, taking account of inline fittings (such as bends, valves and other equipment items. The spreadsheet has four columns which link from one to the ne3t. This can be used to break a piping s&stem down into a number of component sections, if needed.
(&'
Ho) to use this spreadsheet
2.1
Colour Coding The following colour coding is used2 4o3es shaded light green require a user input. 4o3es shaded light blue give a calculated output.
2.2
Calculation Description The spreadsheet leaves space to add a alculation Title at the top, and a 5otes 6ection at the bottom of the sheet. At the top of the calculation column are two bo3es (To and 7rom) to indicate the pipe route. Although these items are not strictl& necessar&, the& help describe the calculation - this can be invaluable it is to be checked b& another engineer. The To and 7rom 6ections are particularl& useful if the calculation is split over several columns.
2.3
Pressure Data The user enters the upstream pressure in the first column. The spreadsheet then calculates the downstream pressure - based on the flow, ph&sical propert& and pipeline data entered (see below). The downstream pressure from the first column is transferred across to the upstream pressure of the second column, thus allowing a pipework network to be built up.
2.4
Physical Property Data The user inputs ph&sical propert& data on the liquid. 2.4.1
Viscosity The user inputs the liquid viscosit& in entipoise (p). 't should be noted that viscosit& changes with temperature - thus the user must ensure that the viscosit& value entered must be at the correct temperature.
%isclaimer2 This calculation provides an estimate for estimating pressure drops in liquid pipelines. #e cannot be held responsible for its use. As with all areas of process engineering, calculations should be checked b& a competent engineer.
www.m&hem1.com
Standard Line Sizing Spreadsheet For Liquids 2.4.2
2.5
evision *A
Density The user inputs the liquid densit& in kg8m9. As with viscosit&, the densit& changes with temperature - thus the user must ensure that the densit& value entered must be at the correct temperature.
Pipe Data 2.5.1
Nominal Pipe Diameter The spreadsheet allows the user to choose from a range of nominal pipe diameters. Available nominal pipe si?es are2 B", C", *", *B", +", 9", :", 0", ;", <", *", *+", *:", *;", *<", +" and ++".
2.5.2
Pipe Schedule The spreadsheet allows the user to choose from a range of available pipe schedules (thicknesses) - these are2 06, *6, +, 9, :, ;, <, *, *+, *:, *;, =6 and ==6. 4& entering the nominal diameter and schedule, the spreadsheet automaticall& retrieves the correct internal diameter of the pipe. 't should be noted that not all combinations of nominal diameter and schedule are permissible> if the wrong combination is selected the spreadsheet displa&s an error. A list of standard pipe si?es can be found b& clicking on the link below2 @ist of 6tandard $ipesi?es n occasions, the user ma& wish to calculate a pressure drop for a non-standard pipe. 'n this case, the user can simpl& over write the internal diameter cell on the spreadsheet (either in inches or mm).
2.5.3
2.6
Pipe Schedule The pressure drop per unit length is affected b& the pipe surface roughness - which depends on the materials of construction. The spreadsheet is provided with a range of possible pipe material t&pes2 glass8tubing, steel (new), steel (corroded), concrete and riveted steel. 4& selecting the piping material t&pe, the spreadsheet automaticall& sets the surface roughness.
Flowrates The user enters the required liquid flowrate in kg per hour. The spreadsheet then calculates the volumetric flowrate (in m 98s), the line velocit& (m8s) and the pressure drop per unit length. (in bar8*m). The calculated line velocit& and pressure drop per unit length can be used to assess whether the pipe diameter is reasonable for the required flowrate.
2.7
Line Losses The spreadsheet can now be used to determine the line losses (pressure drop) through the s&stem. The user enters the total pipe length, as well as the number of inline fittings (bends, valves and Tee-unctions).
%isclaimer2 This calculation provides an estimate for estimating pressure drops in liquid pipelines. #e cannot be held responsible for its use. As with all areas of process engineering, calculations should be checked b& a competent engineer.
www.m&hem1.com
Standard Line Sizing Spreadsheet For Liquids
evision *A
The spreadsheet then calculates the line losses - see 6ummar& 6ection below.
%isclaimer2 This calculation provides an estimate for estimating pressure drops in liquid pipelines. #e cannot be held responsible for its use. As with all areas of process engineering, calculations should be checked b& a competent engineer.
www.m&hem1.com
Standard Line Sizing Spreadsheet For Liquids 2.
evision *A
!ther Pressure Drops As well as line losses, the spreadsheet accounts for two other pressure drops. 2.8.1
Elevation han!es 7or liquid s&stems, variation in height can have a maor impact onto the total pressure drop. To account for this, the spreadsheet allows the user to enter changes in elevation.
2.8.2
-
7or increases in elevation - i.e. the end of the pipe is higher than the inlet, the change in elevation should be entered as a positive num.er (this will result in a larger total pressure drop than if t he pipe had been level.
-
7or decreases in elevation - i.e. the end of the pipe is lower than the inlet, the change in elevation should be entered as a negative num.er (this will result in a smaller total pressure drop than if the pipe had been level.
"ther Pressure Drops The user has the opportunit& to enter other pressure drops not accounted for in the line losses and changes in elevation sections. These could be2 -
2."
$ressure drops due to orifice plates. $ressure drops due to inline instrumentation. $ressure drops due to control valves $ressure drops due to equipment items
#u$$ary The summar& section provides a summar& of the calculation results, namel&2 -
alculated line losses alculated static head gain ther pressure drops.
These three values are used to calculate the total pressure drop in the line and the downstream pressure.
*&'
+uilding a ,iping $et)or-
7or pressure drop calculations down a single pipe, onl& the first column of the pressure drop calculation needs to be used. The other three calculation columns can be ignored. owever, for more comple3 piping s&stems, t he other calculation columns can be used to build up a piping network This can be ver& useful if, for e3ample, the user needs to determine pressure drop in distribution s&stems. To make this easier, the downstream pressure of the first column is used as the upstream pressure of the second column and so on. The ph&sical propert& and flowrate data entered in the first column is copied across to the other three columns to make it easier to set up a network - these values can be overwritten, if required.
%isclaimer2 This calculation provides an estimate for estimating pressure drops in liquid pipelines. #e cannot be held responsible for its use. As with all areas of process engineering, calculations should be checked b& a competent engineer.
www.m&hem1.com
Standard Line Sizing Spreadsheet For Liquids evision *A 6ee ow to use these alculation worksheet for notes on its use.
"alculation Title: 7rom2 To2 Pressure Data !pstream $ressure Physical Property Data Discosit& @iquid %ensit& Pipe Data 5ominal @ine %iameter $ipe 6chedule $ipe Eaterial T&pe 'nternal %iameter 'nternal %iameter Flowrates Eass 7low Dolumetric 7low @ine Delocit& $res drop per *m Line Losses $ipe @ength 5umber of o bends 5umber of valves heck Dalves T-$iece straight run T-$iece as elbow !ther Pressure Drops 1levation 'ncrease ther $ressure %rops #u$$ary @ine @osses 6tatic $ressure Gain ther $ressure %rops Total ,ressure Drop Do)nstream ,ressure
bar (g)
*.+
.<0
.<0
.<0
*.
*.
*.
*.
*
*
*
*
*.0 *6 6teel (5ew) *.;< :+.F
.0 : 6teel (5ew) .;+ *0.<
9. : 6teel (5ew) 9.F FF.
9. : 6teel (5ew) 9.F FF.
kg8h
+,*;
+,*;
+,*;
+,*;
m98h m8s bar8*m
+.*; .:+ .;
+.*; 9.; <.;;
+.*; .*9 .9
+.*; .*9 .9
m
+<
m bar
. .
. .
. .
. .
bar bar bar .ar .ar 0g1
.*F . . '&%/ '&23
. . . '&'' '&23
. . . '&'' '&23
. . . '&'' '&23
p 9
kg8m
inches
inches mm
%otes
Disclaimer: This calculation provides an estimate for estimating pressure drops in liquid pipelines. #e cannot be held responsible
for its use. As with all areas of process engineering, calculations should be checked b& a competent engineer.
for its use. As with all areas of process engineering, calculations should be checked b& a competent engineer.
evision2 *A
www.m&hem1.com
Standard Line Sizing Spreadsheet For Liquids "#L"L#TIO$ TH!OR4 %&'
Introduction
This spreadsheet can be used to calculate pressure drops in pipelines, taking account of inline fittings (such as bends, valves and other equipment items. To use the spreadsheet, follow the instructions given in the "ow to !se this 6preadsheet" #orksheet. This worksheet presents the equations and algorithms used in the calculation and discusses elements of fluid flow theor&.
(&'
"alculation o5 ,ressure Drop
2.1
Deter$ining Pipe Di$ensions ommercial pipes come in standard si?es, specif ied in terms of the nominal pipe diameter, and the pipe schedule. The spreadsheet has this information alread& stored within the calculation worksheet, linked to the internal diameter (in inches). The spreadsheet retrieves the correct internal diameter using a @ookup command. The internal diameter, d, (in metres) is used to calculate the cross-sectional flow area, A, (in square metres) using 1quation *2
A H 2.2
π d :
+
1quation (*)
Deter$ining the Line &elocity The line velocit&, u, (in m8s) is calculated using 1quation +.
u H
m ρ A
1quation (+)
#here2 m - Eass flowrate (in kg8s) ρ - @iquid densit& (in kg8m9) A - ross-sectional flow area (in m+)
2.3
Calculation o' the (eynolds %u$)er The e&nolds number is a dimensionless group giving a measure of whether to flow is laminar or turbulent. 't is used to estimate the friction factor (see below). A discussion on e&nolds 5umber and its importance can be found via the following link2 e&nolds 5umber The e&nolds number, e, is calculated using 1quation 92
e H
ρud µ
1quation (9)
#here µ - Discosit& (in $a.s)
%isclaimer2 This calculation provides an estimate for estimating pressure drops in liquid pipelines. #e cannot be held responsible for its use. As with all areas of process engineering, calculations should be checked b& a competent engineer.
evision2 *A
www.m&hem1.com
Standard Line Sizing Spreadsheet For Liquids 2.4
Calculation o' the Pipe (elati*e (oughness The pressure drop from flow down a pipe - at least in turbulent flow - is affected b& the roughness of the pipe surface. bviousl&, the pipe roughness is determined b& the pipe materials of construction. The spreadsheet provides t&pical pipe roughness values for a range of materials i.e. Eaterials Tubing8Glass 6teel (5ew) 6teel (orroded) ast 'ron oncrete iveted 6teel
$ipe oughness +.1-; m 0.1-0 m *.1-9 m +.;1-: m 9.1-: m 0.1-9 m
Ta.le %: oughness values for different pipe materials
The effect of pipe roughness becomes less important as the pipe diameter increases, thus the spreadsheet calculates the pipe roughness relative to the pipe diameter using 1quation :.
ε d
$ipe elative oughness H
1quation (:)
#here2 ε $ipe roughness (in m) d - $ipe internal diameter (in m)
2.5
Calculation o' the Fanning Friction Factor The 7anning 7riction 7actor is a dimensionless number which, along with the pipe velocit&, can be used to estimate the pressure drop of flow down a pipe. 't is a function of the e&nolds number and, for turbulent flow, the pipe relative roughness. A introduction to the 7anning 7riction 7actor can be found via the following link2 7anning 7riction 7actor The 7anning 7riction 7actor can be determined from harts (Eood& %iagram) or b& using an empirical equation. A number of 7riction 7actor orrelations are available in the literature, the one used in this spreadsheet is the hurchill orrelation see 1quations 0, ; and F. 1
f 7anning H + 3
< e
*+
* (A I 4)*.0
I
/12
1quation (0)
#here
16
* A H +.:0F 3 ln
F e
.
I .+F 3
ε d
1quation (;)
and
4 H
9F09 e
16
1quation (F)
%isclaimer2 This calculation provides an estimate for estimating pressure drops in liquid pipelines. #e cannot be held responsible for its use. As with all areas of process engineering, calculations should be checked b& a competent engineer.
evision2 *A
www.m&hem1.com
Standard Line Sizing Spreadsheet For Liquids
%isclaimer2 This calculation provides an estimate for estimating pressure drops in liquid pipelines. #e cannot be held responsible for its use. As with all areas of process engineering, calculations should be checked b& a competent engineer.
evision2 *A
www.m&hem1.com
Standard Line Sizing Spreadsheet For Liquids The hurchill orrelation is used as it is applicable to both laminar and turbulent flow - this is not the case all correlations. 't should be noted that the 7anning 7riction 7actor is 5T the same as other 7riction 7actors2 i.e. %arc& and Eood&
2.6
Calculation o' the Pressure Drop per +nit Length o' #traight Pipe The pressure loss as a liquid flows down a straight length of pipe is given b& the %arc& 1quation. This is e3pressed in 1quation < below.
∆$
$ipe
: f 7anning @$ipe H d
ρ.u+ +
1quation (<)
#here ∆$$ipe -
$ipe line pressure drop (in $a) @$ipe - $ipe length (in m)
An introduction to the %arc& 1quation is given via the attached link2 'ntroduction to the %arc& 1quation 't should be noted that the form of the equation presented via this link uses the %arc& 7riction 7actor, which is four times larger than the 7anning 7riction 7actor. 1quation < can be adapted to calculate the $ressure per * metres b& setting @$ipe to * and converting from $a to 4ar - see 1quation .
4ar per *m
2.7
metres : f 7anning 3 * ρ.u+ H + d 3 *0 $a 8 bar
1quation ()
Calculation o' the Pressure Drop ,hrough Pipe Fittings The $ressure %rop through pipe f ittings (e.g. $ipe bends, Dalves, T-$ieces) can be e3pressed in terms of a esistance oefficient, J, where2
∆$
H
J
7ittings
ρ.u+ +
1quation (*)
5.4. 't can be seen from 1quations < and * that the esistance oefficient equates to (:f 7anning@)8d for a straight length of pipe. The spreadsheet uses the following esistance oefficients for different pipe fittings 7itting o 4ends Dalve heck Dalve 6traight Tee piece Thru Tee $iece
esistance oeff, J .< *.+ *.0 .* .F
Ta.le (: esistance oefficient for different pipe fittings
%isclaimer2 This calculation provides an estimate for estimating pressure drops in liquid pipelines. #e cannot be held responsible for its use. As with all areas of process engineering, calculations should be checked b& a competent engineer.
evision2 *A
www.m&hem1.com
Standard Line Sizing Spreadsheet For Liquids bviousl&, these values are appro3imate as J is affected b& factors such as radius of the bend and the valve design. A detailed list of esistance oefficients for different pipe fittings is given in ranes 7low of 7luids book - see link below. 7low of 7luids Technical Guide The @ine @osses value given in the spreadsheet is the sum of the ∆$$ipe and ∆$7ittings.
2.
Calculation o' the #tatic -ead ain The pressure in a liquid s&stem is greatl& affected b& changes in elevation - the s&stem pressure increases with a drop in height. The relationship between pressure and height (converted to bar) is given b& 1quation **
∆$
1levatio n
H
ρ 3 .<* 3 ∆h
*0
1quation (**) $a 8 bar
#here, ∆h is the increase in height The total pressure drop is the sum of the line losses, ∆$1levation and other pressure drop (added manuall& b& the user).
%isclaimer2 This calculation provides an estimate for estimating pressure drops in liquid pipelines. #e cannot be held responsible for its use. As with all areas of process engineering, calculations should be checked b& a competent engineer.