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Process Control Valve – Sizing, Selection and Maintenance

Introduction

Process Control Valve – Sizing, Selection and Maintenance 

Course Objectives

• Know the different type of Control Valves
• Acquaint the participant with the valve characteristics comprising the valve tightness class and the flow characteristics
• Enhance the knowledge of the application, operation and design of different types of valves
• Offer skills, knowledge and understanding of the principles and practices of the associated Codes and Standards related to Control Valves
• Discover the methods for valve selection, specifications and sizing that suit a specific application
• Study methods of valve testing, inspection and troubleshooting established on the industrial and manufacturer codes and standards
• Control Valve Defects, i.e., Travel deviations, Instrument Air defects, Friction, Flashing & Cavitation’s
• Control Valve Bench Set up
• Use Modern Control valve maintenance techniques. i.e., diagnostic, online monitoring, HART

Who Should Attend?

• Instrumentation and Control Engineers & Technicians
• Electrical Engineers & Technicians
• Project Engineers
• Mechanical Engineers & Technicians
• Process Control Engineers
• Consulting Engineers
• Maintenance Engineers & Technicians
• Production Controllers
• Project Managers

Course Outline

MODULE 1:  INTRODUCTION

• Control Valve Terminology
• Control Valve
• Basic Control Loop
• Control Valve Gain
• Hysteresis
• Dead Band (Backlash)
• Hysteresis & Dead Band Effects
• Linearity
• Rangeability
• Turndown
• Accuracy
• Repeatability
• Loop Gain
• Resolution
• Dead Time
• Drift
• Capacity (Valve)
• Friction
• Stiction
• Principles of Valve Throttling Processes

MODULE 2:  CONTROL VALVE STANDARDS

• Well Known Valve Standards
• Instrument Society of America (ISA)
• ANSI -American National Standards Institute
• API – American Petroleum Institute
• ASME-American Society of Mechanical Engineers
• NACE-National Association of Corrosion Engineers

MODULE 3:  CONTROL VALVE COMPONENTS- CONTROL VALVE BODY

• Basic Valve Components- Body- Bonnet- Trim (Plug and Seat)- Packing- Actuator- End Connections
• Control Valve Classification
• Linear (Sliding Stem Valves)
• Globe Valves
• Single-Ported Globe
• Double-Ported Globe Valve
• Application-Throttling general purpose flow control valve
• 3-Way Valves
• Angle Valves
• Z Globe Valve
• Y Globe Valve
• Diaphragm Valve- Diaphragm Valve Assembly-Diaphragm Valve Positions (On-Off)-DIAPHRAGM VALVE POSITIONS (THROTTLING)-Application-Used for Biochemical Processes and For Regulation of Most Gases and Liquids
• Gate Valve-Rising and Non-Rising Stem-Gate Valve with Handwheel- Application-stop valves, (not throttling), high pressure and temp, not for slurries, viscous fluids
• Knife Gate valve
• Rotary Valves
• Ball Valve-Ball Valves Open / Close States-Application-Flow Control, Pressure Control, Shutoff, Corrosive Fluids, Liquids Gases, High Temperature
• Butterfly Valves-Butterfly Positions-Application-Low Pressure, Large Diameter Lines Where Leakage Is Unimportant
• DISC VALVE

MODULE 4: SPECIAL VALVES

• Pressure relief valves
• Pressure safety valves
• Needle Valves
• Check Valves-Swing Check valve-Lift Check Valves-Piston Check Valves-Ball Check Valves

MODULE 5: CONTROL VALVE BODY SELECTION

• Globe (Plug and Seat)
• Butterfly
• Diaphragm / Pinch
• Ball

MODULE 6: CONTROL VALVE PACKING

• What Is Packing?
• Packing in Sliding Stem Valve
• Stationary Loading
• Live-Loaded Valve Stem Packing
• Adjusting Packing Assemble
• Packing Material Selection
• Typical Packing Arrangement
• Typical Packing Friction Values
• Packing Material Specification
• SHUTOFF CLASSES

• VALVE SEAT LEAKAGE
• VALVE LEAKAGE CLASSIFICATIONS

MODULE 7: CONTROL VALVE ACTUATORS

• Actuators
• Pneumatic Actuators
• Diaphragm Actuators-Diaphragm Actuators Assembly
• Piston Actuators
• Double Acting Piston
• Rotating Actuators (Rack-And Pinion Mechanism)
• Hydraulic Actuators-Examples
• Electric Actuators (Mov)
• Hand Actuators
• Self-Actuated Valves
• Self-Operated, Spring-Loaded Gas Pressure Regulating Valve
• Pilot-Loaded or Externally Loaded Pressure Regulator
• Actuator Types Symbols

MODULE 8: VALVE FAILURE MODES

• What is the meaning of Failure?
• Direct/Reverse actions
• Direct Body
• Reverse Body
• Failure modes symbols
• How to choose failure mode for a control valve?

MODULE 9: ACTUATOR BENCH-SET/ACTUATOR RESPONSE

• Introduction
• Bench-Set Adjust-cases
• Actuator response problem
• 1st Using, I/P transducer
• 2nd Using Volume booster
• Volume booster VS Pressure regulator

MODULE 10: CONTROL VALVE POSITIONER/ Solenoid Valve

• Why do we need a positioner?
• Positioner is a control system?
• Advantages of adding positioner
• How can Positioner increase valve seating?
• Electronic positioners
• Examples for electronic positioner
• Examples for Pneumatic positioner
• 2-way solenoid valve
• 3-way solenoid valves
• 4-way solenoid valves
• Summary

MODULE 11: PROXIMITY SWITCH/SPLIT RANGE CONTROL

• Proximity (limit) switch
• Quick Exhaust valve
• Basic Control Strategies
• Split Range Control
• Complementary valve sequencing
• Exclusive valve sequencing
• Progressive valve sequencing

MODULE 12: CONTROL VALVE CHARACTERIZATION

• Inherent versus installed characteristics
• Installed characteristics
• Solving linearity problems
• Ideal Characteristic curves
• Examples
• Modified characteristic curves
• Practical Characteristic curves from manufacturers data
• Valve trim Assignments
• Cage guided
• Ball valve trim
• Summary

MODULE 13: SELECTION GUIDE (CHARACTERISTIC CURVE & BODY TYPE)

• Introduction

• Gate valve
• Globe Valve
• Ball valve
• Butterfly valve
• Selection Steps
• Summary

MODULE 14: CONTROL VALVE SIZING

• What is Valve Sizing?
• Flow Coefficient (CV)
• Valve as a Variable Restriction
• Pressure Drop
• Flow Capacity Coefficient CV
• Choked flow conditions (critical flow)
• Pressure Drop
• Liquid sizing equation
• Liquid Design Equations
• Relative flow capacity
• Typical values for relative flow coefficient
• Procedural steps to Accurately Size A Liquid Control Valve
• Control Valve Sizing Rules of Thumb
• What are the Control Valves sizing procedure?
• Valve Actuator Sizing
• Liquid Sizing Examples
• Design in steps in details
• Gas sizing equations
• Sizing for gases in steps
• Valve Sizing for Compressible Fluids
• Valve Sizing for Compressible Fluids Procedure
• Summary

MODULE 15: CONTROL VALVE ENGINEERING PROBLEMS

• Stiction
• How stiction affect valve movement?
• Flashing-What is flashing?
• Effect of valve body on flashing
• Cavitation
• Preventing flashing
• Use cavitation-control valve trim
• Special trim design
• Ball valve special trim
• Cushion with introduced gas
• Sustain the flashing action
• Chocked flow
• Flow vs ΔP
• Noise Prediction Aerodynamics
• Pressure drop staging
• Flow division
• Special valve trim
• Path control
• Erosion
• Bonnet damage
• Corrosion
• Valves, and how they suitably fit into pressure relief and Safety Instrumented Systems (SIS)
• Using digital controllers, with valves
• Summary

MODULE 16: 3-term Controllers and Loop-tuning for Processes containing Control Valves

• Understanding & implementing the right controller action, for fail-safe valves
• Thoughtfully considering all of the variables, associated with three-term control
• Open loop tuning, for controllers that act and work on control valve loops
• Closed loop tuning, for controllers that act and work on control valve loops
• Trial and error tuning, to improve control valve performance

MODULE 17: Using Valves in Cascade, Ratio, Dead-Time Dominant, Non-Linear & PLC-Controlled Processes

• Setting up a cascade loop, by means of a single valve and multiple controllers
• Setting up a ratio loop, by means of a single valve and multiple process variables (PVs)
• Dead time dominant loops, how this disturbs the valve performance, and how this is corrected
• Using a control valve in a method that exhibits different responses in different zones
• Combining PLCs, for valve control

MODULE 18: INSTALLATION AND MAINTENANCE

• Introduction
• Proper Storage and Protection
• Proper Installation Techniques
• Use Good Piping Practices
• Summary