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Control Valve Fazri Ppt

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informasi mengenai control valve atau yang biasa di kenal dengan final element

Text of Control Valve Fazri Ppt

MAINTENANCE AND CALIBRATION CONTROL VALVE

By Zul Fazri S.M.MAINTENANCE AND CALIBRATION CONTROL VALVE

Control ValveIn an automatic control system, Control Valve is the final control elements that embody the output signal from the controller becomes a movement valve opens or closes the flow so as to return the process variable to a predetermined price.In general function a control valve are:On-Off: Open and close the flow (solenoid valve).

Variable Control: set the size of the flow.

Safety: as a safety process.

General Form of Control ValveBroadly speaking, the control valve comprises:Actuator

Bonnet

Body

PART OF ACTUATOR:ActuatorDiaphragm CaseDiaphragm Diaphragm PlateActuator StemActuator SpringSpring SeatSpring AdjustorYokeStem ConnectorTravel IndicatorTravel Indicator Scale

Action Control ValveDirect ActionReverse Action

Bonnet AssemblySeveral types of bonnet are: Extension Bonnet

Bellows Seal Bonnet

Finned Bonnet

Packing and LubricationBonnet is the portion of control valve that contains the packing box and stem seal and may guide the stem. It provides the principal opening to the body cavity for assembly of internal parts or it may be an integral part of the valve body. It may also provide for attachement of the actuator to the valve body. Typical bonnets are bolted, threaded, welded, pressure-sealed, or integral with the body.(ANSI/ISA 75.05.01-2000 (R2005))Figure Types Of Bonnet are:Extension BonnetFinned BonnetBellow Seal BonnetPacking and Lubrication

Valve BodyValve body or valve body assembly refer to ANSI/ISA 75.05.01 define as the main pressure boundary of the valve that also provides the pipe connecting ends and the fluid flow passageway, and supports the valve trim.

Types of Valve Body:Globe valveNeedle Valve bodies ( bars stock valve bodies)Ball valve bodiesButterfly valve BodyDiaphragm (sounders type) valve bodiesDrag valve bodies

Globe Valve

Butterfly Valve Body

Needle Valve BodyDiaphragm (sounders Type) Valve BodiesBall Valve BodyDrag Valve Bodies

Maintenance and Calibration Control ValveMaintenance PhilosophyCorrectiveAction is taken after an event has accurerred. Wait for something to happen to a valve and then repair or replace it.

PredictiveAction is taken based on the life time the equipment.PreventiveAction is taken on a timetable based on history. Try to prevent something bad from happening.Maintenance ProcessManufacturers Literarture (disassembly of a control valve, inspecting the disassembled control valve, cases and solving problem control valve).

Actuator Diaphragm (stem packing and seat rings).

Grinding Metal Seats (replacement control valve parts, reassembly of the control valve, and reinstalling the control valve).CalibrationCalibration instrument is process or procedure of adjusting an instrument so that its indication or registration is in close agreement with a referenced standard.Calibration EquipmentAir CompressorPresure RegulatorStandart GagesHydrostatic PumpTest Bench

Control Valves Name PlateRead the information that to be written on name plate carefully.Name plate has special information about valve and actuator. The important which is printed on name plate as follow.

SummaryBased on discussion about Maintenance and Calibration Control Valve, summary as the following:Control valve has three function, there are:On OffVariabel controlSafetyControl valve has three main part, there are:Actuator as activatorBonnet as a coupling between body and actuatorBody valve as which is directly contact with media that is controlledMainteance Control Valve, there are:Manufacturers LiteratureActuator DiaphragmGrinding Metal seat

Calibration Control Valve is process or procedure of adjusting an instrument so that its indication or registration is in close agreement with a referenced standard.

THE ENDThank You for Your Attention

Bellow Seal BonnetBonnet ini digunakan bilamana tidak diperbolehkan ada kebocoran sepanjang yang dapat ditolerir.Biasanya digunakan bilamana fluid proses adalah racun, mudah terbakar, mudah menguap, radioaktif, atau material-material yang mahal. Oleh sebab itu pemilihan bellow seal bonnet harus benar-benar diperhatikan dengan hati-hati.

Extention BonnetDigunakan untuk temperatur tinggi atau rendah sehingga packing stem terhindar dari temperatur yang extrim tersebut. standart packing yang umum digunakan dengan temperatur kerjanya sampai 4500 F (2320 C) tetapi mudah rusak pada temperatur rendah. Extention bonnet dapat memindahkan packing box dari bonnet agak jauh untuk mencegah terhadap temperatur yang terlalu rendah dari proses sehingga temperatur dari packing berada pada range yang diinginkan.

. Finned BonnetUmumnya packing material dibatasi penggunaannya karena temperatur yang tinggi. Untuk melayani kebutuhan temperatur tinggi digunakan packing yang tahan temperatur tinggi atau dengan menggunakan Finnet bonnet seperti pada gambar., yang bertujuan untuk memperbesar luasan sehingga panas dapat dibuang dengan mudah.

Packing dan LubricatingPacking yang paling banyak digunakan sebagai bahan untuk packing karena mempunyai kemampuan pelumasan sendiri (selflubricating) dan tidak perlu diberi minyak.

Input SignalOutput

ATO (Fail Close)ATC (Fail Open)

15 psi

9

3 Open Close (Full Close) 100% 100%

50%50% 0 CloseOpen 0

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