Control System Security

Digital Control Systems and their associated industrial networks/protocols are extending the depth to which bi-directional communications extend throughout an enterprise. In many cases, the underlying technology for the business network and the process control network are the same. Consequently, many of the risks that are found in today's corporate or business environments can now impact the reliable operation of the process control system. This page and the links...

Fuzzy Logic

Fuzzy Control System - Fuzzy logic is widely used in machine control. The term itself inspires a certain skepticism, sounding equivalent to "half-baked logic" or "bogus logic", but the "fuzzy" part does not refer to a lack of rigour in the method, rather to the fact that the logic involved can deal with fuzzy concepts-concepts that cannot be expressed as "true" or "false" but rather as "partially true". Although genetic algorithms and neural networks can perform just as well as...

Dynamic Process Simulators and Training Systems

Immersive Virtual Reality Plant - A Comprehensive Plant-Crew Training Solution Improves Process Reliability and Safety - Capital-intensive industries face the challenge of replacing an aging workforce with a computer-savvy, gaming generation over the next five years. Industries such as oil and gas,refining and power companies must institutionalize their workforce knowledge in efficient and effective ways. Leveraging virtual reality (VR) models...

Choke Valves

Go to Specific Subject: Choke Valve General Information | Choke Valve Design Specification | Choke Valve Maintenance and Inspection | Common Choke Valve Problems and Solutions | Choke Valve Papers and Applications | Subsea Choke Valves | Choke Control Systems


Choke Valve General Information

Choke Valves are severe service valves which are designed specifically for oil and gas wellhead applications, both in a surface and subsurface context. They are used for controlling the...

Composite Valves

Composite valves are made from strong, light weight composite materials. Their graphite and fiberglass reinforced thermoset and thermoplastic resins are resistant to acids, caustics, bleaches and more than one thousand other industrial and waste treatment chemicals, at half the cost of traditional alloy valves.

Go to Specific Subject: Basics about Composite Valves | Application and Selection of Composite Valves | Typical Composite Valve Specifications | Composite Valve...

Control Valves

This Comprehensive Control Valve Technical Information Page covers Selection and Design, Cavitation and Flashing in Control Valves, Control Valve Actuators, Butterfly Control Valves, Control Valve Sizing, Split Range Control Valves, Control Valve Applications, Control Valve Noise Calculation and Prediction, Control Valve Maintenance, Control Valve Positioners and Self Operated Regulators.

Scroll Down for Technical Information on Control Valves

Go to Specific Subject: Control...

Evaluation of ControlValve Performance is Necessary in Plant Betterment Programs

Sanjay V. Sherikar, Ph.D., P.E.
22591 Avenida Empressa
Rancho Santa Margarita, CA 92688
Phone (949) 858 1877
Fax (949) 858 1878
E-mail: This email address is being protected from spambots. You need JavaScript enabled to view it..


Control valves affect the performance of power plant in terms of output, heat rate, reliability and availability because they are the final control elements in the operation. Therefore, critical evaluation of control valves must to be an integral...

Fire Safe Control Valve Actuators

An essential part of equipment safety is to be able to maintain the fail-safe position when a fire breaks out. In case of pneumatic linear actuators, the fail-safe position must be assumed and maintained when air supply fails or the diaphragm ruptures.

Usually, springs are used to perform this task. They force the valve to move to the fail-safe position when dangerous situations emerge or damages occur. On failure of air supply, the Actuator springs act...

Fluid Kinetic Energy as a Selection Criteria for Control Valves


A selection criteria is provided that assures a control valve will perform its control function without the attendant problems of erosion, vibration, noise and short life. The criteria involves limits on the fluid kinetic energy exiting through the valve throttling area. Use of this criteria has resolved existing valve problems as demonstrated by retrofitting of the internals of many valves and vibration measurements...

Getting Optimum Performance through Feedwater Control Valve Modifications

Brian Leimkuehler, P.E.
(Presently at ComEd, LaSalle County Nuclear Station)

Sanjay V. Sherikar, P.E.
22591 Avenida Empressa
Rancho Santa Margarita, CA 92688

FROM: Sixth EPRI Valve Technology Symposium
July 14-16, 1997
Portland, Maine


Good control of the feedwater system is very important for smooth operation at nuclear power plants. The performance of the feedwater control valves, which are the final...

Specialist Power Plant Valves

HORA is one of Germany's leading manufacturers of control valves with more than 35 years of experience. This independent company specialises in the design and manufacture of severe service valves in power plants, e.g turbine bypass stations, desuperheaters, pump protection valves and feedwater control valves. The company's minimum flow valves protect centrifugal pumps from potential damage caused by thermal and hydraulic overloads at low load operations. Hora...

Pressure Regulators

A Pressure Regulator automatically regulates the flow to maintain pressure in accordance with the amount of demand.

Go to Specific Area of Interest: Pressure Regulator Technical Information | Principal of Operation and Sizing of Pressure Regulators | Pressure Regulator "Droop" | Pilot Operated Regulators | Tank Blanketing Valves | Vacuum Regulators and Breakers |


Pressure Regulator Technical Information

The following information is from GO Regulator:


Pressure Safety Relief Valves

Safety and Relief Valves for Steam, Gas, Vapour & Liquid Service - Protection of personnel and equipment is the paramount concern in the selection of safety relief valves for plant operating systems. Only the most reliable safety valves should be considered for such a crucial role. 

Go to PSV Engineering Headers that interest you by clicking on the hyperlinks: Technical Data | Sizing and Selection | Two Phase Relief Sizing | Safety Relief Valve Design |

Rupture Discs

Rupture Disc Technical Information

An Introduction to Rupture Disc Technology - from BS&B.

The following excellent technical references are from Cheresources Philip Leckner:

Rupture Disk Specification

Whilst every effort is made to ensure technical accuracy of the information supplied on, Keyfleet Pty Ltd and its employees accept no liability for any loss or damage caused by error or omission from the data supplied. Users should make and rely on their own independent inquiries. By accessing the site users accept this condition. Should you note any error/omission or an article offends please do not ignore it, contact the This email address is being...

Understanding IEC Aerodynamic Noise Prediction for Control Valves

Floyd D. Jury
Technical Consultant, Fisher Controls International, Inc.

ICEWeb thanks Fisher Controls for permission to include this article

In 1995, the International Electrotechnical Commission (IEC) released International Standard IEC 534-8-3 which is designed to calculate a sound pressure level for aerodynamic noise pro-duced by a control valve. This internationally approved and accepted standard is important because it...

Instrument Valves and Accessories


Instrument Valves and Accessories are a critical part of any Instrument Hook Up. The valves and accessories include those listed below. 

Go to Specific Subject: Common Questions Associated with Instrument Valves and Accessories | Instrument Ball Valves | Instrument Bleed Valves | Instrument Check Valves | Close Coupled Mono flange and Large Bore Direct Mount Manifold | Primary Isolation Double Block and Bleed Valves | Instrument Excess Flow Valves |


CANopen - CANopen is a CAN-based higher layer protocol. It was developed as a standardized embedded network with highly flexible configuration capabilities. CANopen was designed for motion-oriented machine control networks, such as handling systems. By now it is used in many various fields, such as medical equipment, off-road vehicles, maritime electronics, public transportation, building automation, etc.

CAN-do Cable Solutions for Many Applications - Previously, automobiles...

Fieldbus – Competent People will be at a Premium

Whatever digital fieldbus is your preference, if one wishes to maximise personal marketability it is time to think about gaining the competencies required to implement the technology.

Few would remember the last watershed in instrumentation, that is the change from pneumatics to electronics. Unfortunately I do and recollect it really hit home hard. At the time we had Scientific Instrument Makers who were responsible for the pneumatics and all...

Highway Addressable Remote Transducer Protocol (HART)

Go to areas of Interest: Highway Addressable Remote Transducer Protocol (HART) | Smart HART Transmitters, Monitors and Interfaces | HART Technical Information | Wireless HART


Highway Addressable Remote Transducer Protocol (HART)

HART - The Premier Tool for Asset Management - Cut downtime and improve profits with the tools you already have - Do more with less. That’s the mantra of many industries today in North America or anywhere...

Industrial Ethernet

Industrial Ethernet - The use of Ethernet as an industrial network is a subject for which still very little documentation is available. This publication focuses entirely on this type of usage of Ethernet, and how this relates to the operation of Ethernet. A difference between an office-user of Ethernet and an industrial user of Ethernet is that the former is not interested in (seemingly trivial) details of internal Ethernet operation, while the latter must sometimes know...


Modbus has been around for years and is utilised comprehensively by Industry.

The following technical information is from Moore Industries-Pacific, Inc.
Using MODBUS for Process Control and Automation - MODBUS is the most popular industrial protocol being used today, for good reasons. It is simple, inexpensive, universal and easy to use. Even though MODBUS has been around for nearly 30 years, almost all major industrial instrumentation and automation equipment vendors continue to...


PROFIBUS - This multidrop technology has been available for a number of years and is particularly suitable in the manufacturing environment. Does not have Control in the field option at present. Particularly favoured in Germany where it was developed. Lots of technical information can be found at this excellent Profibus site.  You have to register to get to it.

Profibus - A comprehensive 44 page technical paper from Samson Controls.

Fieldbus Wars revisited?  There has been an...

Why should you Choose Intrinsic Safety rather than Flameproof or FNICO for Fieldbus Applications?

The answer here is “why not” choose Intrinsic Safety since a fieldbus power supply is required for Exd, whilst a Fieldbus Non Incendive Concept (FNICO) power supply is required for FNICO (Zone 2 only) and a Fieldbus Intrinsically Safe Concept (FISCO) power supply for Zone 1.

Zone 0 applications can be accommodated by additional hardware and use of the Entity concept.The Entity concept limits...