Course Objectives :
Upon completing this Process Control Valves – Selection, Inspection and Maintenance course successfully, participants will have an understanding and know or be able to do after attending this course:
- To introduce the participant to different type of Control Valves.
- To familiarize the participant with the valve characteristics including the valve tightness class and the flow characteristics
- To upgrade the participants understanding of the application, operation and design of different types of valves
- To provide skills, knowledge and understanding of the principles and practices of the related Codes and Standards related to Control Valves
- To learn the methods for valve selection, specifications and sizing that suit a particular application
- To learn methods of valve testing, inspection and troubleshooting based 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
- Modern Control valve maintenance techniques. i.e. diagnostic, online monitoring, HART
Training Methodology:
- Participants will learn by active participation during the program using exercises, questionnaire, syndicate and group discussion.
Course Outlines:
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
- Capacity (Valve)
- Friction
- Stiction
- Principles Of Valve Throttling Processes
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
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
CONTROL VALVE BODY SELECTION/ CONTROL VALVE PACKING:
- Globe (Plug and Seat)
- Butterfly
- Diaphragm / Pinch
- Ball
- 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
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
VALVE FAILURE MODES/ ACTUATOR BENCH-SET/ACTUATOR RESPONSE:
- What is the meaning Failure?
- Direct/Reverse actions
- Direct Body
- Reverse Body
- Failure modes Symbols
- How to select failure mode for a control valve
- Introduction
- Bench-Set Adjust-cases
- Actuator response problem
- 1st Using I/P transducer-I/P transducer
- 2nd Using Volume booster
- Volume booster VS Pressure regulator
CONTROL VALVE POSITIONER/ SPLIT RANGE CONTROL/CONTROL VALVE CHARACTERIZATION:
- Why do we need a positioner?
- Positioner is a control system.
- Advantages of adding positioner
- How can Positioner increase valve seating
- Electronic positioners (Flowserve 3200 MD Smart Positioner)
- Examples for electronic and Pneumatic positioner
- Split range Control
- Complementary valve sequencing
- Exclusive valve sequencing
- Progressive valve sequencing
- 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
CONTROL VALVE ENGINEERING PROBLEMS/3-term Controllers and Loop-tuning for Processes containing Control Valves:
- 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 drops staging
- Flow division
- Special valve trim
- Path control
- Erosion
- Bonnet damage
- Corrosion
- Valves, and how they fit into pressure relief and Safety Instrumented Systems (SIS)
- Using digital controllers, with valves
- Understanding & implementing the right controller action, for fail-safe valves
- Understanding all of the variables, associated with three-term control
- Open loop tuning, for controllers that act on control valve loops
- Closed loop tuning, for controllers that act on control valve loops
- Trial and error tuning, to optimize control valve performance
Using Valves in Cascade, Ratio, Dead-Time Dominant, Non-Linear & PLC-Controlled Processes/ Installation and Maintenance:
- Setting up a cascade loop, using a single valve and multiple controllers
- Setting up a ratio loop, using a single valve and multiple process variables (PVs)
- Dead time dominant loops, how this affects the valve performance, and how this is corrected
- Using a control valve in a process that exhibits different responses in different zones
- Combining PLCs, for valve control
- Proper Storage and Protection
- Proper Installation Techniques
- Use Good Piping Practices