What are the factors to consider when selecting a control valve?

5 Factors to Consider When Choosing a Valve

• Media Type. The characteristics of the liquid or gas type being controlled will determine the valve material that should be used.
• Application Conditions.
• Valve Function.
• Actuation Method.
• Maintenance Requirements.

What controls the operation of the valves?

The actuator is used to move the valve stem. They are usually air (pneumatically) or electrically driven. The controller calculates the size of the change to the valve internal passage to bring the flow to the desired rate.

How do air directional control valves work?

DCVs allow fluid flow (hydraulic oil, water or air) into different paths from one or more sources. DCVs will usually consist of a spool inside a cylinder which is mechanically or electrically actuated. The position of the spool restricts or permits flow, thus it controls the fluid flow.

How are the directional control valves classified?

Directional control valves are classified according to certain factors like inlet control element structure, number of ports or ways, number of position, method of actuation, and center position flow pattern. In a directional control valve, the internal control element would be a sliding spool, rotary spool or ball.

How do you choose valves?

The right valve choice means matching the valve’s size to expected flow through the system. Know the chemical compatibility requirements. The valve materials need to be compatible with the gases or liquids flowing through it. Plastic valves usually resist harsh or corrosive chemicals better than metal valves.

Which type of valve is best for controlling the flow?

ball valves
Globe valves are considered the industry standard for control valves because they are good at regulating flow, whereas ball valves are better for on/off control without pressure drop.

What are the chapters included in the control valve course?

Here is a list of the chapters that are included: 1. Introduction to Control Valves 2. The History of Control Valves 3. Terminology 4. Valve Bodies 5. Control Valve Actuators 6. Sizing 7. Cavitation and Flashing 8. Control Valve Noise 9. Control Valve Trim 10.

What is the function of a control valve?

A control valve is a power operated device capable of modulating flow at varying degrees between minimal flow and full capacity in response to a signal from the controlling system. Control valves may be broadly classified by their function as “on-off” type or “flow regulating” type.

Is the Neles flow control manual worth reading?

I have found the Neles “Flow Control Manual” to be an invaluable source of information on the application of control valves and recommend it as reading and reference material to anyone who is seriously involved In the use or application of control valves. The chapters in the book are: Plus appendices containing useful reference material.

What is a stem guide valve?

stem guide: A guide bushing closely fitted to the valve stem and aligned with the seat. – 9 – three-way valve: A valve with three end connections, used for mixing or diverting flow. throttling: The action of a control valve to regulate fluid flow by varying the position of the closure member.