training - flowserve apm pump cw pump

8/17/2019 Training - Flowserve Apm Pump Cw Pump

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IntroductionPersonnel qualification and training

•All personnel involved in the operation, installation, inspection andmaintenance of the unit must be qualified to carry out the workinvolved.

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Centrifugal Pump Basics


Rev-0 CIRCULATING WATER PUMP - O & M TRAINING 2 of 97


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Why do we need pumps?


To force liquid into a pressure vessel – Pumps move liquid from a low pressure area to a higher pressure

area.


How Centrifugal Pumps function?


•A centrifugal pump works on the principle of converting the kineticenergy of a flowing liquid (velocity pressure) into static pressure.

•This action is described by Bernoulli's Principle.

•Bernoulli's principle states that an increase in velocity occurssimultaneously with decrease in pressure.

Flowserve Corporation Property and Confidential



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Bernoulli's Principle



The figure above illustrates how the airparticles separate at the front of the wingand join back together at the back.



The energy conversion results in an increased pressure on thedownstream side of the pump causing flow.


Typical Centrifugal Pump



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Point A:The liquid enters thepump at the suctionflange.




Point B:The liquid flows intothe eye of the impeller.




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Centrifugal Pump BasicsPositive Displacement v s. Centrifugal Pumps


Centrifugal Pump BasicsPositive Displacement v s. Centrifugal Pumps




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Centrifugal Pumps



Centrifugal Pump BasicsFoot Mounted Pumps

• Mounted by their feet to the base• Normally found in low temperature applications

• At high temperatures, the shaft to driver alignment will be affected


Overhung Foot MountedRadial Split Pump

Between Bearings FootMounted Axial Split Pump

Multi Stage Foot MountedRadial Split Pump



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Centrifugal Pump BasicsCenterline Mounted Pumps

•Required by The American Petroleum Institute (API)•Allows for heat expansion•Pump and driver alignment will not be affected


Overhung Centerline Mounted Multi Stage Centerline Mounted

Q&A




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Centrifugal Pump BasicsUnderstanding Hydraulic Thrust in the Pump

•Thrust is the hydraulic forces acting on the impeller

•Created by pressures developed in and around the impeller

•Change of direction of flow through the impeller.


Centrifugal Pump BasicsRadial Forces in a Pump

The pressure being higher in area 2than in area 1 causes a radial force

acting against the rotating element asindicated in picture.

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2



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Centrifugal Pump BasicsControl of Radial Forces in the Pump

•Single volute

•Double volute

•Diffuser style casing


Single volute

Centrifugal Pump BasicsSingle Volute Compared to Double Volute Type Casing

Radial forces are more balanced in a double or dual volute style pump.


Double Volute



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Centrifugal Pump BasicsDiffuser Style Pump

• Fluid directed by multiple cutwaters

• Results in near balancing of radial forces

• Normally used in high to very high head applications.


Centrifugal Pump BasicsCasing Types Radial Load Comparison

Minimum radial force is at Best Efficiency Point(BEP) with operation to the right or left of BEP

producing higher radial loads.


Pump Curve



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Centrifugal Pump BasicsImpeller Designs

Impeller designs grouped as either radial flow, mixed flow, or axial flowdepending on their hydraulic geometry.


Mixed Flow Closed Impeller Double Suction

Impeller Types


Impeller configuration as enclosed impeller, semi-open impeller, opensimpeller. In addition, Impeller types can identify single suction or double

suction configurations.


Open Impeller Semi-open Reverse Vane



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Centrifugal Pump BasicsSealing Device

A device used to control leakage between the rotating pump shaft andthe stationary pump case or rear cover, usually either packing or amechanical seal.


Centrifugal Pump BasicsSupport for Radial Forces

•Radial bearing

•Wear rings


The radial bearing is closest to theimpeller commonly on overhung pumps



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Centrifugal Pump BasicsMain Advantage for Using Wear Rings

• Reduced maintenance cost

• Front wear rings reduce internal recirculation

• Back wear reduce axial thrust and moderate the seal chamberpressure.


Centrifugal Pump Basics Axial Forces in the Pump

Axial force is the result of higherpressure forming behind the

impeller forcing the impeller in thedirection of lowest pressure

Shaft Axial Movement




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Pump Support for Ax ial Forces


Thrust bearings (Axial bearings) isnormally the bigger bearing or twoback to back bearings and lockeddown in the pump casing


Axial Bearing (Thrust Bearing)

Balance Holes and Impeller Back Vanes


•The balance holes allow the liquid that has moved behind the impellerto pass through

•Resulting in reduced axial loads on the pump


Impeller Balance Holes



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Balance Holes and Impeller Back Vanes


•Back pumping vanes remove the liquid frombehind the impeller and pump it toward thepump discharge

•Moderate the seal chamber pressure as wellas reduce the axial loads.


Impeller Back Vanes

Using a Balance Drum For Multistage Ring Section Pumps



Ring Section Radial Split Pumpfitted with Balance Drum



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Impeller Back t o Back Ar rangements


•For multistage double volute style pumps

•The axial thrust is partly balanced


Rotor indicate the direction of fl ow within t he pump

Using a Double Suction Impeller


•For single stage pumps•Low pressure at both ends of the pump

•Result in axial balance of the rotating element


Between Bearings Axial Split pump with dou ble suction impeller

training - flowserve apm pump cw pump

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