how to size a pump_booster

Specifying Irrigation Pump Stations

How to Size and Specify Booster Pumps

Tony AdamsonRain Bird Pump Sales & Marketing Manager

How to Size and Specify Pumps for a Booster Application

Booster Application

Suction Discharge

20 PSIG 80 PSIG

Pump that is developing 60 PSI (138.6 Feet of Head)

What is the Water Source?Well

Lake

Pond

River

Ditch

Public Source (metered or pressurized)

Above Ground Tank

What needs to be determined to specify a pump?

Required Flow Rate

Inlet and Discharge Pressure

Water Application Requirements (e.g., water window)

Pump station location – any restrictions such as size, existing building, view of the public, etc.

Elevation – impacts how the pumps are rated

Inlet/Outlet piping size requirements

Available power in volts/phase/hertz

Pumps for the Application

Centrifugal– Typically up to 2000GPM– Typically up to 130PSI

Vertical Multi-stage– Up to 500GPM per pump – Wide range of pressure

Vertical Multi-Stage

Split Case

Horizontal End Suction

Vertical Turbine

Submersible Turbine

Pumps for the Application

Pump Motor

Location

Pump Motor Location

• Vertical Turbine• Typically up to 1000GPM per pump• Wide range of pressure• Motor on top

• Submersible Turbine• Typically up to 600GPM per pump • Wide range of pressure• Motor on bottom

Variable Frequency Drive (VFD)

1) Soft starting of every motor provides motor longevity

2) VFD saves energy by only powering the pumps that are needed based upon demand

3) Heat Exchanger keeps the VFD cooled and the electrical box free from dirt and dust

Every main motor on a Rain Bird Pump Station is started on the Variable Frequency Drive (VFD).

Key Numbers and Units

You get 100GPM @ 120PSI for every 10HP– 60HP pump delivers 600GPM @ 120PSI– 75HP pump delivers 750GPM @ 120PSI– If pressure ↓, flow ↑

100PSI = 231FT– The discharge of a pump is usually stated in Feet– The discharge of a pump station is usually stated in PSI

Friction Loss (Schedule 40 Steel Pipe) – 1000GPM in a 10” pipe suffers 5FT head loss per 1000FT

of pipe

Electrical PowerMost common types of power in U.S.– 460 V, 60Hz, 3Φ

Can power pumps up 500HP– 230 V, 60Hz, 3Φ

Can power pumps up to 100HP– 230 V, 60Hz, 1Φ

The largest motor available in 1Φ 230V is 10HP

Rest of the World Power:– Canada: 575 V, 60Hz, 3Φ– Asia & Middle East: 380V, 50Hz, 3Φ

Hydraulic Design - Pump Curves

The Pump Curve

Bowl Power

Bowl Efficiency

NPSHr

BEP(Best Efficiency Point)

The Pump Curve

Bowl Power – The power input required to generate a given flow and pressure.

Bowl Efficiency – The ratio of hydraulic power output from the bowl to the power input to the bowl– e.g. A bowl with required a 75HP motor to generate a 50HP

hydraulic output would have a Bowl Efficiency of 50/75 = 67%

BEP (Best Efficiency Point) – Point of highest bowl efficiency. You want your operating point to be as close to BEP as possible.

NPSHr – Net Positive Suction Head Required – Pressure required on the intake side of the pump to ensure proper operation.

The Pump Curve


Bowl Efficiency – The ratio of hydraulic power output from the bowl to the power input to the bowl– e.g. A bowl that requires a 75HP motor to generate a 50HP

hydraulic output has a Bowl Efficiency of 50/75 = 67%



The Pump Curve






The Pump CurveBowl Power – The power input required to generate a given flow and pressure.





Low Profile Pump

Pump Selection –

Based on pressure and flow

Electrical Calculations

Estimating Station FLA**For 208V applications, increase the FLA by 10%

To calculate the FLA of a pump motor operating on a VFD, multiple the nominal FLA by 1.24

To estimate FLA, multiple the largest load by 1.25 and then add this to remaining component FLAs.

Example: a 460V 2 x 100HP pump station with a 25HP PM pump would have an FLA of 340 Amps.

334 Amps = 1.24x1.25x120A + 120A + 34A

Surge Protection. Helps protect the

pump station against transients associated

with power disturbances.

Through-Door Main Electrical Disconnect. Shuts off power to the electrical panel if the panel door is opened.

Step-down Transformer.

Provides 120V single phase control power.

Optional 7.5KVA Step Down Transformer. Provides additional

120V power.

Other Electrical Panel Components

Specifying a Booster Station

A contractor has a 200GPM line from the city coming in at 15PSIG. He needs to boost the pressure to 155PSIG to overcome elevation changes at the site.

The contractor requests a two pump system for redundancy purposes.

The altitude at the site is 1900FT.

Available power is 208V, 3Φ

100GPM at 140PSI

100GPM at 140PSI

200GPM at 155PSI

15 PSIG

155 PSIG


155PSI – 15PSI = 140PSI140PSI is referred to as the Pump Differential Pressure.200GPM at 155PSI 2 pumps, each capable of providing 100GPM at 140PSI.Add 5PSI to account for station losses100GPM at 145PSI 100GPM at 335FTNote: The high pressure requirement indicates that a vertical multi-stage pump should be used. Use the published pump curves to select pump.


Vertical Multi-Stage : 15HP 72.5% Efficient

Insert Pump Curve for the 2-15HP

Vertical Multi-Stage : 15HP 72.5% Efficient

Horizontal End Suction – 35HP 53% Efficient

20% less efficient as vertical multi-stage

Result: two 15HP multi-stage pumps.

Efficiency at the design point is ~72%.

Now calculate the estimated station FLA:

Station FLA = 1.25 x Largest FLA + Remaining FLAs

(1.25 x 1.24 x 42A + 42A) = 118A (200 Amp Service)


Pump Station OptionsControl SystemsZ-PipeStainless Steel Intake Box ScreenPower ConditionerPump Station HeaterLake Level Control Wye StrainerPower Zone Transformer

Filter (Rain Bird, Amiad, Tekleen, Orival or Other)Cable or Radio ModemsFertigationEnclosuresMagnetic Flow Meter (instead of the standard paddle wheel style)AC VFD CoolingPowder Coat, Stainless or HDPE

Display Options

GT1020 Monochrome Touch Screen (Standard)

E1071 Full Color Touch Screen (Option)

Optional Filtration

SiteControl/Smart Pump

• Pump Manager™ provides control of the pump via pressure and flow independently of the any remote system. Also, provides remote computer access to the pump.

• Smart Pump provides direct and real time communication between the pump station and the central control system

• Adjusts flow demand based on actual field conditions to maximize pump efficiency

Rain Bird Pump Stations Design TeamProposal packages with a standardized quotation are provided with 48 hours of completed requests. Drawings are available based on the most common configurations upon request.

Factory Contacts

Sales & MarketingTony Adamson (520) 741-6185Herb Hofmann (602) 725-5517Bill Wise (215) 439-0093

Product ManagerGordon Van Dyke (520) 806-6131

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Pump Station Sales Team: (520) 806-5620

Request for QuotationAlejandro Carrillo (520) 806-5688Robbi Tolksdorf (520) 741-6145Fax # (520) 741-6191 Email [email protected]

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