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300/T H E A X I A L F L O W V A L V E - S E R I E S 3 0 0 / 6 0 0A UNIQUE REGULATOR
W h a t i s t h e A x i a l F l o w V a l v e ?The Axial Flow Valve is a regulating device used to control gas pressure in natural gas transmission and distribution applications worldwide.
The Axial Flow Valve is the principle regulator used in most of Elster instromet's Pressure Reduction Stations.
The Axial Flow Valve (AFV) has a number of key advantages over similar regulators.
• It is very compact
• Greater capacity 'size for size' compared with similar regulators
• It is very simple in construction and operation
• Simplicity - reliable and easy to maintain
• It has a wide range of application using one common design
• A proven, low risk design which has been in the market for over 30 years
The Axial Flow Valve is an industry standard for pressure regulation indistribution and transmission applications. Elster Instromet offer a full rangeof Axial Flow Valve regulators to cover mbar to Class 600 applications andsizes from 50mm to 300mm. The regulator is pilot controlled and ElsterInstromet can provide a full range of supporting controls.
The generation of noise during the pressure reduction process can causeproblems in sensitive locations. Noise reduction is an increasinglyimportant environmental, social and personnel safety issue.
In response to these demands, Elster Instromet has enhanced its rangeof Axial Flow Valve regulators by incorporating an integral silencer. Thenovel metal foam insert reduces noise significantly and can eliminatethe need for expensive traditional noise reduction measures such ascladding or acoustic enclosures.
Based on extensive research and development, Elster Instromet canprovide noise prediction calculations specific to your application and operating conditions.
The silencing element fits within the body of the Axial Flow Valve andits simplicity and form is unchanged, making it ideal for retrofitapplications.
Maintenance intervals are unaltered. Elster Instromet can supply fullyassembled Quiet Axial Flow Valves, or a silencing kit enabling existinginstallations to be upgraded.
I n t r o d u c i n g t h e ' Q u i e t ' A x i a l F l o w V a l v e ( Q A F V )
/600T H E A X I A L F L O W V A L V E - S E R I E S 3 0 0 / 6 0 0BENEFITS
SIMPLE* Only 4 componentsThe unique axial concept consists of only four maincomponents; A high integrity flexible membrane, inlet and outlet flow cages and a body.
* One des ign conceptcovers all pressure ratings and sizes
* Interchangeable componentsAll components are fully interchangeable and reversiblereducing the need for spares and extending operating life.
* Compact and l ightweightThe Axial Flow Valve is the most compact and lightweightregulator in its class
* One bol t construct ionThe Axial Flow Valve construction means that no special tools or techniques are required to dismantle or re-assemble.
* Wafer des ignThe Axial Flow Valve design allows installation between flanges and compact back to back arrangements.
REDUCED COSTS* Greater capac i tyCompared with similar regulators, the Axial FlowValve offers greater capacity 'size-for-size'.
* Extended serv ice l i feLong life components and unique 'reversible' sleeveextends service life.
* Lower noiseThe design of the Axial Flow Valve means that it is quieter 'size-for-size' compared with otherregulators. This can be reduced further by fittingthe quiet trim to the Axial Flow Valve (QAFV).
* Common tra in ingThe common design for all sizes means commontraining and procedures for operational andmaintenance staff.
* L ightweight and compactThe compact size of the Axial means that theoverall size and footprint of a Pressure ReductionModule can be reduced. Back to back installation orwith porting ring considerably reduces overallstation dimensions. This in turn means smallerkiosk/land requirements.
RELIABLEThe Axial Flow Valve is renowned forreliability. Some of the design features thatcontribute to this are:
* Only one moving partan expandable sleeve is the only moving part,eliminating friction and sliding wear
* Sta in less Stee l C losureon the inlet and outlet, are hardened to resistabrasion and improve control.
* Toro ida l S leeve Des ignensures longer sleeve life, positive closureand smoother operation.
I N T E R C H A N G E A B L EV A L V E C A G E C L O S U R E V A L V E B O D Y
R U B B E R S L E E V ES I N G L E W O R K I N G P A R T
V A L V E C A G E C L O S U R E
Q U I E T T R I M
O - R I N GF A I R I N G
N U TW A S H E RB O L T
VERSATILEThe design of the Axial Flow Valvemeans that it can be used in a widerange of applications. A simplechange of sleeve upgrades the axialflow valve from one pressure rangeto another. A change of control willconvert the axial from pressure tovolumetric control or to monitoroverride, or safety control.Conversion from pressure control torelief duty is also achieved in thisway - without modification to theaxial flow valve.
Utilising the appropriate controlsystem, the Axial Flow Valve can beused for:
* Pressure reduction from 100 bardown to 30 mbar
* Active or monitor mode
* Two stage pressure cut
* Volumetric flow control
* Over and under pressure shut off
* Back pressure/relief valve
* Pulsation dampening
* Remote control via pneumatic or electronic signal
* Can be installed in any position
* Low operating differential
T H E A X I A L F L O W V A L V E - S E R I E S 3 0 0 / 6 0 0B E N E F I T S
E a s y t om a i n t a i nThe simplicity of the AxialFlow Valve makesmaintenance easy. Whilst no special tools are strictlyrequired, Elster instromet canprovide a range of simple,effective tools to makemaintenance even simpler.
* Easy to Mainta inFully interchangeable andreversible components and thewafer design construction, ensurethat the axial flow valve is simpleto install, remove and maintain.
* Minimal SparesWith only two body ratings, andfour models covering a range ofpressures from 0.1 bar to 100 bar,spares are kept to a minimum.The only spares required for eachsize of valve are a sleeve andthree 'O'-rings.
* Extended Serv ice L i fe
The Axial Flow Valves unique'reversible' sleeve extends service life
* Maintenance ToolsElster Instromet can provideadditional tools to makemaintenance even simpler.
300/600
T H E A X I A L F L O W V A L V E - S E R I E S 3 0 0 / 6 0 0M A I N T E N A N C E A N D A C C E S S O R I E S
The simplicity of the Axial Flow Valve
makes maintenance easy. Whilst no
special tools are strictly required,
Elster Instromet can provide a range
of simple, effective tools to make
maintenance even simpler.
Despite claims that top entry regulatorsdesigns are easier to maintain the Axialremains the simplest device in its' class. Try comparing the removal andmaintenance of a 300mm Axial Flow Valvewith an equivalent sized top entryregulator; the added complexity of the topentry design together with more bolts toremove and heavy covers can makemaintenance time consuming and difficult.Additionally, lifting equipment is stillrequired for larger top entry regulators.
Center ing TubesThe Axial Flow Valve is awafer design which simplybolts between flanges. Toensure exact centering ofthe valve for full capacity,centering tubes are easilyfitted over the existingbolts. (Series 300 only).
L i f t ing EyeOne lifting eye fits all sizes, howeveronly the two largest sizes generallyrequire lifting equipment.
FlangeSpreadersTo make removaleven easier, theaxial flow valvecan be suppliedwith simpleflange spreaders.
300/600
Fai r ingnutsocketA specialsocket forfairing nutremoval isavailablefrom ElsterInstromet.
300/600
Flow L imiterCertain applications such as relief dutyrequire that the maximum flow rate islimited. Elster Instromet can supplyrestrictors and limiters for regulator andrelief applications.
Pre-piped p i lot loopsElster Instromet can design and supplycomplete, pre-piped pilot control loopsincluding ancillary systems such aspressure profiling or clock pilots. Pleasecontact us to discuss your requirements.
Port ing RingsWhen space is limited, Axial Flow Valvesmay be fitted back-to-back by use of aporting ring. This enables two stageconfiguration in a very compact area.
Operat ing indicatorAn Elster Instromet Model 150Differential Pressure Gauge can befitted to indicate valve operation and opening.
L i f t ing dav i t andmount ing postTo assist with removal of thelarger Axial Flow Valve sizes,Elster Instromet can supply anewly designed lifting davit. Thismeets all recent approvals andmay be supplied as an option onnew build stations or fitted to anexisting skid by adding themounting post. The lifting davitis also used with the Elster Series10 Orpheus, reducing cost andenabling the davits to be usedwith a mix of station types bothabove and below ground.
Other accessor ies . . . . .
Support j igThe Axial Flow Valve may besupported in a variety of wayswhilst removing the centre bolt.Elster Instromet can provide a jigthat supports the control galleryon the AFV and eases bolt removal.
T H E A X I A L F L O W V A L V E - S E R I E S 3 0 0 / 6 0 0H O W I T W O R K S
View 1With gas supply pressure at theback of the sleeve equal to inletpressure, the sleeve is closedagainst the inlet cage. A closingforce equal to inlet pressure actson the downstream 'V' sleevearea forcing it against thedownstream cage to give doubleclosure and completely tight seal.
View 2Reducing the pressure at the back ofthe sleeve creates a pressureimbalance across the sleeve, inletpressure now being higher. Thisexpands the sleeve away from thecages thereby allowing flow frominlet to outlet. The pressure at theback of the sleeve can now bereferred to as the 'Control' Pressure.
View 3Reducing the control pressurefurther increases the differentialacross the sleeve allowing it toexpand further until the sleeve isflat against the body for 100%capacity. The position of thesleeve, and therefore flow, iscontrolled by the pressure at theback of the sleeve.
The heart of the Axial Flow ValveTM is the unique 'V' form flexible sleeve. Thisis the only moving part. Throttling and control is performed by the sleeveexpanding and contracting in relation to the inlet and outlet slotted cageswhich fit inside the sleeve and are formed to match the 'V; configuration. Anouter cylindrical body surrounds the cage and sleeve assembly forming a 'V'shaped cavity all around the sleeve. All four parts are held together with asingle bolt through the centre of the cages. Control is achieved by modulatingthe pressure in the cavity at the back of the sleeve.
T H E A X I A L F L O W V A L V E - S E R I E S 3 0 0 / 6 0 0C O N T R O L S Y S T E M S
CONTROLTo control the pressure on theback of the sleeve, two controlsystems are available.
Insp i rator Contro l(Standard)For general transmission/distribution, minimal pressuredifferential and enhanced control applications
Operat ionAs the operator opens, a flowand hence pressure drop iscreated across the inspirator. The inspirator boosts the pressuredrop to the back of the axial sleeve by approximately 3:1.
Restr ictor Contro lFor fast response and applicationswith minimal downstream volumes.
Operat ionAs the operator opens, a flow andhence pressure drop is created acrossthe restrictor. This pressure drop istransferred directly to the back of theaxial sleeve.
In practice there are many differentcontrol system configurations. Elstercan supply the Axial Flow Valve as acomponent or with a pre-piped PilotControl Loop. Please call ElsterInstromet to discuss your application.
O P E R A T O R
T O A X I A L S L E E V E
F I X E DI N S P I R A T O R
E X T E R N A LS U P P L Y
( P 1 )
S U P P L Y F I L T E R `
A D J U S T A B L ER E S T R I C T O R
P 1 P 2
INSPIRATOR CONTROL
RESTRICTOR CONTROL
P 1 P 2
O P E R A T O R
T OO P E R A T O R
A D J U S T A B L ER E S T R I C T O R
S U P P L YF I L T E R
I N T E R N A LS U P P L Y
( P 1 )
T O A X I A LS L E E V E
300/600OPERATORSThere are many ways of operating the Axial Flow Valve,the simplest being the spring loaded pilot. This devicesimply monitors the condition to be controlled andopens or closes accordingly.
The photo below shows a simple pressure controllingpilot, which is spring biased open.
As the downstream pressure falls, the pilot opens andbleeds off control pressure downstream. A rise indownstream pressure causes the pilot to close thusincreasing the control pressure to the back of the sleeve.
Remote operation can be achieved in a variety of ways,using external electronic controllers and suitable I to Pconverters. Elster Instromet can also supply a motorisedactuator for control of pilots.
T H E A X I A L F L O W V A L V E - S E R I E S 3 0 0 / 6 0 0C O N T R O L S Y S T E M S
300/600Technical
Elster can provide a PC based design tool that makessizing calculations quick, accurate and easy. In additionfield or office based applications engineers are available toassist with design and selection. Please give us a call.
Inlet pressure - 140 mbar - 100 bar
Flow range - 0-106 Sm3/h
Outlet pressure - 30 mbar - 50 bar
Infinite turn down - Suitable for most gases
- For very small capacities or relief applications, fitting an internal
flow limiter can restrict the range of the Axial Flow Valve.
Please call Elster Instromet for details.
E N V I R O N M E N TA L D ATANoiseNoise prediction estimates can be provided for the axialflow valve and complete installation on request.
These calculations are based upon a combination ofempirical data using established Elster formulae forpressure regulator sizing.
Extensive field tests have resulted in very significantimprovements in terms of integrity, fluid dynamics andfull bandwidth noise attenuation.
Key benefits of the Quiet Axial Flow Valve include:
• Significant noise reduction achievable
• Integral silencer means simplicity
and form of AFV unchanged
• Ideal for retrofit applications
• Maintenance intervals identical to standard AFV
T H E A X I A L F L O W V A L V E - S E R I E S 3 0 0 / 6 0 0
S E R I E S 3 0 0
Size DN50 DN80 DN100 DN150 DN200 DN300
Weight (kg) 3 4.5 9.0 18 37 81
S E R I E S 6 0 0
Size DN50 DN80 DN100 DN150 DN200 DN300
Weight (kg) 4 14 34 56NOT
AVAILABLENOT
AVAILABLE
Elster Metering Ltd 4 Pate Road, Melton Mowbray, Leicestershire LE13 0RG
Main: Tel: +44 (0)1664 567797 Fax: +44 (0)1664 410254
Email: [email protected] www.elster-instromet.com
E L S T E R I N S T R O M E T I S A W O R L D C L A S S S U P P L I E R O F T O T A L G A S M E A S U R E M E N T
A N D C O N T R O L S Y S T E M S
For further information contact:
Part No. 92-2089 D11609 09/03
Elster Instromet Axial Flow Valves
are CE marked and conform with
the Pressure Equipment
Directive and EN/334.
Further details onour full rangeavailable on request
All rights strictly reserved. No part of this document maybe stored in any retrieval system, or any form or by anymeans without prior written permission from ElsterInstromet Limited. Every effort has been taken to ensurethe accuracy of this specification. However, ElsterInstromet operate a continuous improvement policy andwe are continually improving our products and systemswhich could, without notice, result in amendments oromissions to this specification. We cannot acceptresponsibility for damage, injury, loss or expensesresulting therefrom. Please contact Elster Instromet forlatest product information.
