Centrifugal Pump Rating Calculation

CENTRIFUGAL PUMP GUIDE

TEMPLATE CREATED BY : Vikram SharmaDATE OF CREATION : 14th of April 2013VERSION : ATITLE OF TEMPLATE : Centrifugal Pump Calculation Template

1. DISCLAIMER

This template was created by Vikram Sharma with the intention for academic purpose. It may be used for preliminary design engineering calculation with the approval for principal / custodian / subjectmatter expert. Point to note that this calculation template shall not be used for detail engineering calculation and designer / user shall use the program that is provided by contractor. If this tool is to be used for detail engineering without the approval of principal / custodian / subject matter expert, the designer / user shall bear full responsibility of the accuracy and validity of the results obtained from thistool. Any comments about this template, please email it to [email protected].

2. WHAT IS A CENTRIFUGAL PUMP?

A centrifugal pump is an equipment that converts the input power to kinetic energy. The energy conversion is done by accelerating the liquid by a rotating item called impeller.Liquid enters the pump through the eye of the impeller which is rotating at high speed. The rotation of the impeller accelerates radially outward the liquid from the pump casing. Due to this rotation, a vacuum is created at the impeller eye that consistenly draws in more liquid into the pump. The energy transferred to the liquid relates tothe velocity at the edge or tip of the vane impeller. Therefore, it can be said that the faster the impeller revolution or bigger the impeller size, the velocity of the liquid willbe higher.

3. IMPORTANT FEATURES

Require input from userScroll down optionIndicative cell for nature of flow.Contains built-in formula to provide results.

4. PUMP FUNDAMENTALSa. Suction and Discharge Vessel / Tank Dimensions

LZAHH : Trip alarm when the liquid reached the maximum level height. In other words, high level trip.HLL : High working liquid level.LLL : Low working liquid level.

b. Pump DimensionsHs,e : Elevation height of suction vessel / tank from ground / grade.Hs,f : Height of pump suction flange from ground / grade.Hd,f : Height of pump discharge flange from ground / grade.

Hd : Height of discharge pipe from ground / grade.Hd,e : Elevation height of discharge vessel / tank from ground / grade.

c. Fluid Important ParameterRated Mass flow (RM) : It is defined as the mass flow rate (kg/h) multiplied by a design factor (%)

Rated Vol flow (RV) : Rated Mass Flow (RM) (kg/h) / Density (kg/m3)

Nominal Diameter (DN) : Outer diameter of the pipe (m) based on the requirements set by PTS 31.38.01.11.

Inner Diameter (I.D) : It is defined as the the outer diameter of the pipe based on the DN and pipe size charts and the corresponding thickness

Liquid Velocity : It is calculated based on the equations provided below.

Reynolds's Number (Re) : It is a dimensionless parameter to determine the nature of flow of liquid, i.e. laminar, transition or turbulent.

Moody's friction factor (fm) : A value that is used to describe the friction factor of a pipe based on the flow, i.e. laminar or turbulent.

Static Height of Liquid (ΔPs,st) : The pressure exerted by the liquid due to its height in the vessel / tank

Suction Pressure (Ps) : It is calculated based on the Minimum Operating Pressure of the suction vessel minus the pressure drop at the suction due to friction, items and equipments

Discharge Pressure (Pd) : It is calculated based on the Design Pressure of the receiving vessel / tank or battery limit at the receiving side, and the pressure drop at the discharge side due to friction, items and equipments.

Differential Pressure (DP) : It is the pressure difference between discharge and suction in bar.

Differential Head (DH) : It is basically the differential pressure converted to head based on the equation provided below.

Rated Mass Flow (RM ) = Normal Mass Flowrate (M ) x Design Factor (%)

Rated Vol. Flow (RV) = Rated Mass Flow (RM ) / Density (ρ)

Inner Diameter (I.D) = Outer Diameter (O.D) - 2 x Thickness (t)

Rated Mass Flow (RM ) = Density of Liquid (ρ) x Cross Sectional Area based on I.D of suction or discharge x Velocity (VL,s or VL,d)

Reynolds (Re) = [Density (ρ) x Liquid Velocity (VL,s or VL,d) x Inner Diameter (I.D) ] / Viscosity (µ)

Laminar: Re = 64 / Re ; Turbulent: 1/(√f ) = -2 log10 [ (ɛ/3.7D) + (2.51/Re√f) ]

Suction vessel : 0.0981 x (LLL - Hs,e - Hs,f) x (ρ/1000)

Discharge vessel : 0.0981 x (Hd - Hd,f) x (ρ/1000)

Suction Pressure (Ps) = Min. Op. Pressure (MiOP) - Σ (ΔPs,f + ΔPs,e + ΔPs,i)

Discharge Pressure (Ps) = Design Pressure / B.L at the receiving side + Σ (ΔPd,f+ ΔPd,e + ΔPd,i)

Differential Pressure (DP) = Discharge Pressure (bar) - Suction Pressure (bar)

Hydraulic Horse Power (hyd kW) : It is describe as the power provided by hydraulic system. It is directly proportional to flow rate and pressure. Besides this, it is inversely proportional to the efficiency of a system.

Brake Horsepower (bk kW) : Also known as shaft horsepower. It is defined as the real horsepower going to the pump. It shall not be equated to the horsepower used by the motor.

Temp. rise due to pumping (Tr) : It is a measure of temperature rise due to pumping and it is calculated based on the equation provided below.

In this equation, the efficiency is expressed in decimal. Therefore, an efficiency of 78.0% is represented as 0.780. Also, the specific heat capacity is expressed inkCal/kgºC.

Pump Shut Off Head (Pso) : Pump shut off head is described as the pumping of liquid "upwards" until it reached a certain height and from this point, the pump is unable to push the liquidup any more further. It is calculated using the equation provided below.

5. REFERENCES

5a. Website(s)http://www.cheresources.com/invision/topic/9646-centrifugal-pumps/http://www.slideshare.net/mahuda72/centrifugal-pump-sizing-selection-and-design-practices-4425151

5b. E-book(s)Section 12 - Pumps & Hydraulic Turbines, Engineering Data Book 12th Ed. SI Vol. I and IISection 17 - Fluid Flow and Piping, Engineering Data Book 12th Ed. SI Vol. I and II

5c. Standard(s)Petronas Technical Standards - Design and Engineering Practice Manual - Piping - General Requirements PTS 31.38.01.11 November 2009.

Differential Head (DH) = Differential Pressure (bar) x (0.0981 x (ρ/1000))

Hydraulic Horsepower (hyd kW) = [Rated Vol. Flow (RV) x Diff. Head (DH) x Gravity Acceleration (g) x Liquid Density (ρ)] / 3,600,000

Break Horsepower (bk kW) = hydraulic Horsepower (hyd kW) / Efficiency (%)

Temp. rise (Tr) = [ Differential Head (DH) / ( Specific Heat Capacity (Cp) x 427) ] x [ (1/e) -1 ]

Pump Shut Off 1(Pso,1) = [ 1.25 x (Pd - Ps) ] + DP of Suct. Vessel / Tank + Max Suction Pressure at HLL Pump Shut Off 2 (Pso,2) = [ 1.25 x (Pd - Ps) ] + [ 0.0981 x (HLL + Hs,e - Hs,f) x SG ]

CENTRIFUGAL PUMP GUIDE

This template was created by Vikram Sharma with the intention for academic purpose. It may be used for preliminary design engineering calculation with the approval for principal / custodian / subjectmatter expert. Point to note that this calculation template shall not be used for detail engineering calculation and designer / user shall use the program that is provided by contractor. If this tool is to be used for detail engineering without the approval of principal / custodian / subject matter expert, the designer / user shall bear full responsibility of the accuracy and validity of the results obtained from thistool. Any comments about this template, please email it to [email protected].

A centrifugal pump is an equipment that converts the input power to kinetic energy. The energy conversion is done by accelerating the liquid by a rotating item called impeller.Liquid enters the pump through the eye of the impeller which is rotating at high speed. The rotation of the impeller accelerates radially outward the liquid from the pump casing. Due to this rotation, a vacuum is created at the impeller eye that consistenly draws in more liquid into the pump. The energy transferred to the liquid relates tothe velocity at the edge or tip of the vane impeller. Therefore, it can be said that the faster the impeller revolution or bigger the impeller size, the velocity of the liquid will

Trip alarm when the liquid reached the maximum level height. In other words, high level trip.

Elevation height of suction vessel / tank from ground / grade.Height of pump suction flange from ground / grade.Height of pump discharge flange from ground / grade.Height of discharge pipe from ground / grade.Elevation height of discharge vessel / tank from ground / grade.

It is defined as the mass flow rate (kg/h) multiplied by a design factor (%)

Rated Mass Flow (RM) (kg/h) / Density (kg/m3)

Outer diameter of the pipe (m) based on the requirements set by PTS 31.38.01.11.

It is defined as the the outer diameter of the pipe based on the DN and pipe size charts and the corresponding thickness

It is calculated based on the equations provided below.

It is a dimensionless parameter to determine the nature of flow of liquid, i.e. laminar, transition or turbulent.

A value that is used to describe the friction factor of a pipe based on the flow, i.e. laminar or turbulent.

: The pressure exerted by the liquid due to its height in the vessel / tank

It is calculated based on the Minimum Operating Pressure of the suction vessel minus the pressure drop at the suction due to friction, items and equipments

It is calculated based on the Design Pressure of the receiving vessel / tank or battery limit at the receiving side, and the pressure drop at the discharge side due to friction, items

It is the pressure difference between discharge and suction in bar.

It is basically the differential pressure converted to head based on the equation provided below.

Rated Mass Flow (RM ) = Normal Mass Flowrate (M ) x Design Factor (%)

Rated Vol. Flow (RV) = Rated Mass Flow (RM ) / Density (ρ)

Inner Diameter (I.D) = Outer Diameter (O.D) - 2 x Thickness (t)

Rated Mass Flow (RM ) = Density of Liquid (ρ) x Cross Sectional Area based on I.D of suction or discharge x Velocity (VL,s or VL,d)

Reynolds (Re) = [Density (ρ) x Liquid Velocity (VL,s or VL,d) x Inner Diameter (I.D) ] / Viscosity (µ)

Laminar: Re = 64 / Re ; Turbulent: 1/(√f ) = -2 log10 [ (ɛ/3.7D) + (2.51/Re√f) ]

Suction vessel : 0.0981 x (LLL - Hs,e - Hs,f) x (ρ/1000)

Discharge vessel : 0.0981 x (Hd - Hd,f) x (ρ/1000)

Suction Pressure (Ps) = Min. Op. Pressure (MiOP) - Σ (ΔPs,f + ΔPs,e + ΔPs,i)

Discharge Pressure (Ps) = Design Pressure / B.L at the receiving side + Σ (ΔPd,f+ ΔPd,e + ΔPd,i)

Differential Pressure (DP) = Discharge Pressure (bar) - Suction Pressure (bar)

It is describe as the power provided by hydraulic system. It is directly proportional to flow rate and pressure. Besides this, it is inversely proportional to the efficiency

Also known as shaft horsepower. It is defined as the real horsepower going to the pump. It shall not be equated to the horsepower used by the motor.

It is a measure of temperature rise due to pumping and it is calculated based on the equation provided below.

In this equation, the efficiency is expressed in decimal. Therefore, an efficiency of 78.0% is represented as 0.780. Also, the specific heat capacity is expressed in

Pump shut off head is described as the pumping of liquid "upwards" until it reached a certain height and from this point, the pump is unable to push the liquidup any more further. It is calculated using the equation provided below.

http://www.slideshare.net/mahuda72/centrifugal-pump-sizing-selection-and-design-practices-4425151

Section 12 - Pumps & Hydraulic Turbines, Engineering Data Book 12th Ed. SI Vol. I and II

Petronas Technical Standards - Design and Engineering Practice Manual - Piping - General Requirements PTS 31.38.01.11 November 2009.

Differential Head (DH) = Differential Pressure (bar) x (0.0981 x (ρ/1000))

Hydraulic Horsepower (hyd kW) = [Rated Vol. Flow (RV) x Diff. Head (DH) x Gravity Acceleration (g) x Liquid Density (ρ)] / 3,600,000

Break Horsepower (bk kW) = hydraulic Horsepower (hyd kW) / Efficiency (%)

Temp. rise (Tr) = [ Differential Head (DH) / ( Specific Heat Capacity (Cp) x 427) ] x [ (1/e) -1 ]

Pump Shut Off 1(Pso,1) = [ 1.25 x (Pd - Ps) ] + DP of Suct. Vessel / Tank + Max Suction Pressure at HLL Pump Shut Off 2 (Pso,2) = [ 1.25 x (Pd - Ps) ] + [ 0.0981 x (HLL + Hs,e - Hs,f) x SG ]

CENTRIFUGAL PUMP GUIDE

This template was created by Vikram Sharma with the intention for academic purpose. It may be used for preliminary design engineering calculation with the approval for principal / custodian / subjectmatter expert. Point to note that this calculation template shall not be used for detail engineering calculation and designer / user shall use the program that is provided by contractor. If this tool is to be used for detail engineering without the approval of principal / custodian / subject matter expert, the designer / user shall bear full responsibility of the accuracy and validity of the results obtained from this

A centrifugal pump is an equipment that converts the input power to kinetic energy. The energy conversion is done by accelerating the liquid by a rotating item called impeller.Liquid enters the pump through the eye of the impeller which is rotating at high speed. The rotation of the impeller accelerates radially outward the liquid from the pump casing. Due to this rotation, a vacuum is created at the impeller eye that consistenly draws in more liquid into the pump. The energy transferred to the liquid relates tothe velocity at the edge or tip of the vane impeller. Therefore, it can be said that the faster the impeller revolution or bigger the impeller size, the velocity of the liquid will

It is calculated based on the Minimum Operating Pressure of the suction vessel minus the pressure drop at the suction due to friction, items and equipments

It is calculated based on the Design Pressure of the receiving vessel / tank or battery limit at the receiving side, and the pressure drop at the discharge side due to friction, items

Rated Mass Flow (RM ) = Density of Liquid (ρ) x Cross Sectional Area based on I.D of suction or discharge x Velocity (VL,s or VL,d)

It is describe as the power provided by hydraulic system. It is directly proportional to flow rate and pressure. Besides this, it is inversely proportional to the efficiency

Also known as shaft horsepower. It is defined as the real horsepower going to the pump. It shall not be equated to the horsepower used by the motor.

In this equation, the efficiency is expressed in decimal. Therefore, an efficiency of 78.0% is represented as 0.780. Also, the specific heat capacity is expressed in

Pump shut off head is described as the pumping of liquid "upwards" until it reached a certain height and from this point, the pump is unable to push the liquid

Hydraulic Horsepower (hyd kW) = [Rated Vol. Flow (RV) x Diff. Head (DH) x Gravity Acceleration (g) x Liquid Density (ρ)] / 3,600,000

CENTRIFUGAL PUMP CALCULATION TEMPLATE

PROJECT: AUTHOR:

LOCATION: VERIFIED:

CLIENT: APPROVED:

CONTRACTOR:

1. GENERAL INFORMATION

Name of Liquid: Visc. (ν):

Pump. Temp (T,p): ºC Vap. Pressure (Pv):

Density @ 15ºC (ρ): kg/m3 Mass Flow (M):

Visc. (µ): Pa.s Design Factor:

m

m

m

Hs,e = m

Hs,f = m

Hd = m

LZAHH

HLL

LLL

LZAHH

HLL

LLL

Hd,f = m Hd,e =

SUMMARYSUCTION PRESSURE (Ps): bar

DISCHARGE PRESSURE (Pd): barNPSH(A): m

DIFF. PRESSURE (DP): bar

DIFFERENTIAL HEAD (DH): m

HYDRAULIC POWER, hyd kW: kW

BRAKE HORSEPOWER, bk W: kW

TEMP. RISE (Tr): ºC

CENTRIFUGAL PUMP CALCULATION TEMPLATE

DATE: REV:

DATE:

DATE:

Visc. (ν): m2/s Rated Mass Flow (RM):

Vap. Pressure (Pv): bara Specific Gravity (SG):

Mass Flow (M): kg/h Rated Vol. Flow (RV):

Design Factor:

3. SUCTION VESSEL INFORMATION

MiOP of Vessel/Tank: bara

MOP of Vessel/Tank: bara

DP of Vessel/Tank: bara

4. PIPE SUCTION INFORMATION

DN:

Sch. No.:

OD:

Thickness:

Suct. Length (L): Moody's Fric. Factor (Fm):

Design Factor: Suct. Fric. ΔP (ΔPs,f):Abs. roughness (ɛ): Suct. items ΔP (ΔPs,i):

Σ Suct. Length (L): Suct. equip. ΔP (ΔPs,e):Static H. of Liq. (ΔPs,st):

SUCT. PRESSURE (Ps):

5. DISCHARGE VESSEL INFORMATION

MiOP of Vessel/Tank: bara

MOP of Vessel/Tank: baraDP of Vessel/Tank: bara

BL Land. Pres. (P): barm

6. PIPE DISCHARGE INFORMATION

m DN:

Sch. No.:

m OD: Liquid Velocity (VL,d):

Thickness:

Disch. Length (L): m Moody's Fric. Factor (Fm):

Design Factor: Disch. Friction ΔP (ΔPd,f):

m Abs. roughness (ɛ): Disch. items ΔP (ΔPd,i):

Σ Discharge Length (L): m Disch. equip. ΔP (ΔPd,e):Static H. of Liq. (ΔPd,st):

DISCHARGE PRESSURE (Pd):

7. NPSH, DIFFERENTIAL PRESSURE AND HEAD

Vap. Pressure / Head:

Static H. of Liq. / Head:

Σ Suct Pressure Drop ΣΔPs / Head:

8. DIFFERENTIAL PRESSURE AND HEAD

DIFFERENTIAL PRESSURE (DP):

DIFFERENTIAL HEAD (DH):

9. PUMP SHUT-OFF HEAD

Diff. Pres. (DH): bar SHUT-OFF PRESSURE 1:

DP of Suct. Vessel/Tank: bar SHUT-OFF PRESSURE 2:Static H. of Liq. (ΔPs,st): bar

Coefficient for Pso:

10. PUMP EFFICIENCY

Selected Eff. (Es): %

Est. Eff (Ee): %

11. POWER CALCULATIONS

HYDRAULIC POWER, hyd kW:

BRAKE HORSEPOWER, bk W:

12. TEMPERATURE RISE CALCULATION

Specific Heat (Cp): kJ/kgºC

CENTRIFUGAL PUMP CALCULATION TEMPLATE

TYPE OF ITEMS

kg/h VALVE

bar (FULLY

m3/h OPEN)

LZAHH / grade: m

FITTINGS

HLL / grade: m

LLL / grade: m

Nature of flow:

ID: m

Liq. vel. (VL,s): m/sReynolds no. (Re):

Moody's Fric. Factor (Fm): MISCL.

Suct. Fric. ΔP (ΔPs,f): bar

Suct. items ΔP (ΔPs,i): bar TOTAL PRESSURE DROP OF ITEMS (ΔPs/d,i)

Suct. equip. ΔP (ΔPs,e): barStatic H. of Liq. (ΔPs,st): bar

SUCT. PRESSURE (Ps): bar

LZAHH / grade: m

HLL / grade: mLLL / grade: m

COLEBROOK EQUATION SOLVER FOR TURBULENT FLOW

Nature of flow:

ID: m

Liquid Velocity (VL,d): m/sReynold (Re):

Moody's Fric. Factor (Fm): To simply this equation, let's make 1/sqrt(f) = A. Therefore, the above equation

Disch. Friction ΔP (ΔPd,f): bar shall look like:

Disch. items ΔP (ΔPd,i): bar

Disch. equip. ΔP (ΔPd,e): barStatic H. of Liq. (ΔPd,st): bar

DISCHARGE PRESSURE (Pd): bar

MiOP / Head: m

Vap. Pressure / Head: m

Static H. of Liq. / Head: m

Σ Suct Pressure Drop ΣΔPs / Head: m

NPSH(A): m

DIFFERENTIAL PRESSURE (DP): bar

DIFFERENTIAL HEAD (DH): m

SHUT-OFF PRESSURE 1: bar

SHUT-OFF PRESSURE 2: bar Error % (LHS and RHS):

SHUT-OFF HEAD 1: m Moody's Fric. Fac (Fm):

SHUT-OFF HEAD 2: m

Chosen Eff (Ec): %

HYDRAULIC POWER, hyd kW: kW

BRAKE HORSEPOWER, bk W: kW

Specific Heat (Cp): kCal/kgºC

Chosen Eff (Ec):

Diff. Head (DH): m

TEMP. RISE (Tr): ºC

Specific Gravity (SG):

DN:

TYPE OF ITEMS DESCRIPTIONSUCTION SIDE

No. C Le (m)

BALL VALVEReduced bore DN40 and smaller 65

Reduced bore DN50 and smaller 45

GATE VALVEStandard bore 13

Reduced bore DN40 and smaller 65

GLOBE VALVEStraight pattern 340

Y pattern 160

Angle pattern 145

CHECK VALVESwing pattern 135

Ball or piston type, DN40 and smaller 340

PLUG VALVE Regular pattern 45

BUTTERFLY VALVE DN150 and larger 20

TEE-EQUALFlow straight through 20

Flow throughside outlet 65

ELBOW90deg, R = 1.5D 20

45deg, R = 1.5D 16

BEND

90deg, R = 4D 14

90deg, R = 5D 16

180deg, R = 4D 25

180deg, R = 5D 28

STRAINER Pump suction Y-type and bucket type 250

NOZZLEProduct outlet nozzel vessel / tank 32

Product inlet nozzle vessel / tank 64

TOTAL PRESSURE DROP OF ITEMS (ΔPs/d,i)

TYPE OF ITEMS DESCRIPTIONSUCTION SIDE

No. ΔP/item ΔP (bar)

TOTAL PRESSURE DROP OF EQUIPMENTS (ΔPs/d,e)

COLEBROOK EQUATION SOLVER FOR TURBULENT FLOW EQUATION SOLVER FOR LAMINAR FLOW

To simply this equation, let's make 1/sqrt(f) = A. Therefore, the above equation Reynolds's number is represented by the equation presented below.

shall look like:

SUCTION DISCHARGE

Abs. roughness (ɛ): Density (ρ):

ID: m Liq. vel. (VL):

RHS:

A: Reynold's no. (Re):

Reynold's no. (Re): Moody's Fric. Fac. (Fm):

LHS:

Is LHS = RHS?:

Error % (LHS and RHS):Moody's Fric. Fac (Fm):

D

eAA

A

D

eA

A

D

eA

7.310log2

Re

51.210log2

Re

51.210log2

7.310log2

Re

51.2

7.310log2

m

SUCTION SIDE DISCHARGE SIDE

ΔP (bar) No. C Le (m) ΔP (bar)

65

45

13

65

340

160

145

135

340

45

20

20

65

20

16

14

16

25

28

250

32

64

DISCHARGE SIDE

No. ΔP/item ΔP (bar)

EQUATION SOLVER FOR LAMINAR FLOWPIPE DN

15

20

25

40

50

80

Reynolds's number is represented by the equation presented below. 100

Re

64fm

150

200

250

300

350

400

500

600

750

900

1050

SUCTION DISCHARGE SIDE 1200

Density (ρ): kg/m3 1400

Liq. vel. (VL): m/s 1600

ID: m 1800

Visc. (µ): Pa.s 2000

Reynold's no. (Re):Moody's Fric. Fac. (Fm):

IDvl

Re

CENTRIFUGAL PUMPISSUES DESCRIPTION(S)

CENTRIFUGAL PUMPDESCRIPTION(S)

CENTRIFUGAL PUMPDESCRIPTION(S)