Topic: Control Valve Technology Library

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This nifty resource helps you find anything and everything you need to know about control valves without having to endlessly surf the web. It provides descriptions and general information for all valve technologies used in process control and automation applications, and allows you to view online intelligence reports, white papers, articles, and technical book abstracts on all things related to control valves.

Control Valve Technology

A control valve regulates the flow or pressure of a fluid. Control valves normally respond to signals generated by independent devices such as flow meters or temperature gauges. Control valves are normally fitted with actuators and positioners. Pneumatically-actuated globe valves are widely used for control purposes in many industries, although quarter-turn types such as (modified) ball and butterfly valves are also used.

Control valves can also work with hydraulic actuators (also known as hydraulic pilots). These types of valves are also known as Automatic Control Valves. The hydraulic actuators will respond to changes of pressure or flow and will open/close the valve. Automatic Control Valves do not require an external power source, meaning that the fluid pressure is enough to open and close the valve. Automatic control valves include: pressure reducing valves, flow control valves, back-pressure sustaining valves, altitude valves, and relief valves. An altitude valve controls the level of a tank. The altitude valve will remain open while the tank is not full and it will close when the tanks reaches its maximum level. The opening and closing of the valve requires no external power source (electric, pneumatic, or man power), it is done automatically, hence its name.

Control Valves

A control valve regulates the flow or pressure of a fluid. Control valves normally respond to signals generated by independent devices such as flow meters or temperature gauges. Control valves are normally fitted with actuators and positioners. Pneumatically-actuated globe valves are widely used for control purposes in many industries, although quarter-turn types such as (modified) ball and butterfly valves are also used.

Control valves can also work with hydraulic actuators (also known as hydraulic pilots). These types of valves are also known as Automatic Control Valves. The hydraulic actuators will respond to changes of pressure or flow and will open/close the valve. Automatic Control Valves do not require an external power source, meaning that the fluid pressure is enough to open and close the valve. Automatic control valves include: pressure reducing valves, flow control valves, back-pressure sustaining valves, altitude valves, and relief valves. An altitude valve controls the level of a tank. The altitude valve will remain open while the tank is not full and it will close when the tanks reaches its maximum level. The opening and closing of the valve requires no external power source (electric, pneumatic, or man power), it is done automatically, hence its name.

Control Valve Handbook, Fourth Edition The latest update to this classic reference tool, also known as Fisher's Little Black Book, is now available online. This newest version, a staple in the industry for more than 30 years, presents information on control valve performance and new technologies, and includes input from experts in the field. View, save or download your complimentary copy of this invaluable reference tool here.

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We welcome contributions from engineers and technically minded people. Your articles can be anything to do with a control valve or anything to do with the subject of valves that you think will help educate others. Article submission can be in Word, pdf, or html format. If your article is useful to other people, we will add it to our site. Send your articles to wboyes@putman.net.

White Papers: In Depth Research

Predicting Control Valve Noise in Gas and Steam Applications: Valve Trim Exit Velocity Head vs. Valve Outlet Mach Number
Author: Joseph Shahda, Dresser Masoneilan
Posted: 03/18/2010
Predicting and managing control valve noise has long been an important consideration in gas and steam applications, with the dual goals of protecting workers from potential auditory damage and preventing excessive vibration that could destroy equipment and piping, possibly leading to a catastrophic failure.

At first glance, it may seem that a logical way to achieve these goals would be to limit valve trim exit velocity head to a maximum of 480 kilopascals (kPa), and this indeed is how some have addressed the issue. In practical application, however, it is an oversimplified approach that, in many cases, will not produce the desired results. First, it typically requires the use of expensive multi-stage or multi-turn trim designs, which can cost up to 30 percent more than a simpler solution. More importantly, it also can create a false sense of safety.

This article will explain why the focus should instead be on keeping the valve outlet Mach number low. Practical examples will be used to illustrate that:
- Even if the trim exit velocity head is kept below 480 kPa, valve noise can be unacceptably high if the valve outlet Mach number is high.
- Even if the trim exit velocity number is above 480 kPa, valve noise can be kept to acceptable levels - without using costly trim designs - if the valve outlet Mach number is kept low.

Selecting Advanced Automation Solutions for On-Off Valves: Reduce Costs, Improve Reliability and Functionality
Author: Metso Automation
Posted: 01/31/2008
Looking for trouble-free valve solutions to improve uptime and cut operating costs?

Control Valve Handbook, 4th Edition
Author: Emerson Process Management
Posted: 10/27/2006
The Control Valve Handbook has been a primary reference since its first printing in 1965. This fourth edition presents vital information on control valve performance and the latest technologies.

Cost effective leak detection and repair
Author: Honeywell Process Solutions
Posted: 09/06/2006
As the population of valves and safety relief valves continues to grow so do leak detection and repair costs. New wireless technologies offer the potential to reduce these costs significantly while providing access to many new monitor points previously not accessible.

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