Know Your Control Valve Basics?

Industrial Control Valve Cutaway View
Courtesy Cashco

Understanding basic operation and function of control valves, an integral part of many industrial process control loops, is essential for the process engineer, operator, or other stakeholder. This presentation outlines control valve operation, major components, and terminology used to describe valve parts, functions, and principles of operation. A useful reference for stakeholders in need of a refresher course in order to understand what the engineers are saying, it also provides detailed illustrations, charts, and description that will prove valuable to the more technical minded.


What you will find:

• Terminology: A glossary of terms commonly used in the control valve world.
• Control Valve Basic Designs: Control valve classifications, cutaway illustrations showing the operating structure of different valve types, comparisons of varying valve designs.
• Characterization and Trim Design: Flow characteristic curves and comparisons for different valve types, showing how flow responds to valve position change.
• Control Valve Technical Considerations: FTC vs FTO, illustrations showing valve operation.
• Force-Balance Principle: Illustration and formula explanations of this basic operating principle.
• Actuator Basic Designs: Illustrations showing the differing arrangements for actuator operation.
• Control Valve Unit Action: Illustrations, diagrams, and explanations of a range of valve operating conditions, including loss of electrical power and loss of instrument air supply.
• Actuator Benchset Range: Shows practical relationship between instrument air pressure and valve ability to properly operate at various pressure conditions.
• Valve Positioner Basics: Definition of valve positioning, reasons to use a positioner, schematic illustrations of control loops.
• Control Loop Action: Charts and provides examples of 16 combinations of Process, Controller, Positioner, and Control Valve combinations.
• Control Valve Packing Designs: Describes and defines packing, common problems, current state of the art. Cutaway illustrations of various packing arrangements.
• Seat Leakage: Classifications, comparisons of different materials.

There is something of value in the document for everyone, and you will undoubtedly pick up something useful. Thanks go out to the engineers at Cashco for putting this together. You can discuss any aspect of your control valve applications with a product specialist. Your contact is always welcome.

Basic Operation & Function of Industrial Control Valves from Miller Energy, Inc.

Eliminate Glass Tube Level Gauge Maintenance Costs

Magnetic Level Indicators
Courtesy Orion Instruments

Industrial process control often requires the accurate measurement of liquid level within a tank or other vessel. There are numerous device technologies and vendors from which to choose. A recent post on this blog detailed one of the available methodologies, the magnetic level indicator. I urge you to review that short post to familiarize yourself with the operating principles and advantages of applying a magnetic level indicator, not only on future projects, but as a possible replacement of some of your existing level indication instruments.

Orion Instruments, a Magnetrol company, has authored a case study showing how the replacement of glass tube level gauges with magnetic level indicators can reap substantial cost savings over the product lifetime. The case study, included below, takes but one minute of your time to read, and delivers a compelling incentive to consider magnetic level indicators (MLI) for your new projects, even as cost saving replacements for existing glass tube level gauges.

Read the case study. Contact a product specialist to discuss your application for new or replacement level indicators.

Orion instruments magnetic level indicators case study from Miller Energy, Inc.

Magnetic Level Indicators - Knowledge Base and Selection Guide

Magnetic Level Indicators
Courtesy Orion Instruments

Industrial process control frequently involves the storage of liquid in vessels or tanks. Continuous and accurate indication of liquid level within the tank is an essential data point for safety and process management. While there are a number of methods and instrument types utilized to provide tank level measurement, the instrument of choice is often a magnetic level indicator, also referred to as a magnetic level gauge. Its use for providing level indication has a number of positive attributes:

• Construction that is resistant to breakage.

• Measuring indicators, switches, and transmitters mounted externally, without contacting the medium being measured.

• Maintenance free operation. No regular cleaning needed.

• Readable level indication from greater distance than glass sight gauges.

• Magnetic level indicators can accommodate greater fluid level ranges without the need for multiple instruments.

Orion Instruments, a Magnetrol company and industry leader, has produced a comprehensive guide to magnetic level gauges, switches, transmitters, and related products. It delivers experts and newcomers an understandable and clear description of the technology and principals of operation behind magnetic level gauges and instruments. The guide also assists the reader in properly specifying and selecting the best instrument configuration for an application. A table of contents at the front of the document helps readers to quickly find the information they need.

Take a couple minutes to roll through the document and you are likely to find new and useful application tips and product information. Any questions about magnetic level indicators or your process measurement and control applications can be clearly addressed by a product specialist.

Orion instruments magnetic level gauge & instrument selection guide from Miller Energy, Inc.

Process Gas Chromatograph with Practical Implementation of Parallel Chromatography

GC8000
Process Gas Chromatograph
Courtesy Yokogawa Corp.

Gas chromatography is a common analysis tool employed in many areas of industry, including oil and gas, pharmaceutical, chemical, and others. Yokogawa Corporation of America has developed and been delivering top tier GC performance with their GC8000 Process Gas Chromatograph for use in oil and gas, and other industrial applications.

In addition to the ruggedness and reliability for which Yokogawa gas chromatographs are well known, the GC8000 brings a number of innovations and improvements to the company’s process gas chromatography product offering.

> Color touchscreen HMI for easy operation

> Advanced predictive diagnostics and software functions monitor key performance indicators during each analysis to verify analyzer is operating within proper tolerances.

> Parallel chromatography is made practical through the use of the GC Modules provided as part of the GC8000. Virtual GCs can be set up inside a single GC with GC Modules to measure multiple streams simultaneously.

The graphics below expand on this overview of the GC8000 Process Gas Chromatograph, the culmination of Yokogawa’s 55 years of experience in the field. For more detailed information, or to discuss your application specifics, contact a product specialist.

Process Gas Chromatograph - Yokogawa GC8000 from Miller Energy, Inc.

Magnetic Flow Meter – When Is It the Right Selection for Your Project?

Industrial Magnetic Flow Meter

Courtesy Yokogawa Corp.

Flow measurement is a ubiquitous function in the industrial process control field. Anywhere there are pipes, somebody wants to know what, and how much, is passing through them. Fortunately for us engineers, there is a wide array of industrial flow meters capable of measuring some physical characteristic of fluid moving within a pipe that can be translated into a useful measurement of flow rate.

In industry, there are a number of different technologies used to measure a physical property related to fluid motion, referred to as magnetic, ultrasonic, vortex, Coriolis, differential pressure, and several others. Each methodology exists in the market because it may perform better or cost less when meeting certain performance requirements. This article is focused on magnetic flow meters and when they may be a good candidate for your project.

Here is a list of some of the positive attributes of magnetic flow meters.

• Magnetic flow meters have no moving parts, always a plus.
• General construction arrangement allows for use of an interior liner for corrosion resistance.
• With no sensor insertions into the fluid flow, the impact of the instrument on the flow is minimized.
• Accuracy, when compared to other technologies, is high.
• Application to laminar, turbulent, and transitional flow profiles is permissible.
• General insensitivity to fluid viscosity, specific gravity, temperature and pressure.
• Magnetic flow meter technology can be applied to a very wide range of pipe sizes.
• Device responds rapidly to changes in fluid flow.
• Can be successfully applied to liquids containing heavy particulates.
• Generally long service life with little maintenance.

There are, though, some points about magnetic flow meters which may make them unsuitable for your application.

• Magnetic flow meters only work on liquids with conductivity above a certain threshold. They may be unsuitable for use with hydrocarbons and high purity water for this reason.
• Cannot be used to measure gas flow.
• Pipe must be grounded.
• Typically, the pipe cross section must be filled by the fluid being measured.

This listing of positives and negatives is intended to be very general in nature. Some manufacturers may have product application solutions that overcome some of the negatives, while others may not be able to deliver all of the positives.

Your best course of action:

Use this general overview to start shaping you understanding of where magnetic flow meters may be a good option, and contact a product application specialist to discuss what you want to accomplish. Combining your process knowledge with their product knowledge should move you toward a good solution.

Industrial Flowmeter Handbook From Yokogawa

Magnetic Flowmeter
Courtesy Yokogawa Corp.

Measuring the volume, mass, density, and temperature of flowing fluids is a common and necessary function of industrial process control. Industrial flowmeters employ various measuring technologies to deliver accurate measurements, which are utilized to make safety, operational, and financial decisions.

Each measurement technology; magnetic, Coriolis, vortex, differential pressure, rotameter, ultrasonic, or another, has specific attributes of meter design and measurement principle making it more suitable to differing application classes. Yokogawa Corporation has summarized the suitability of the different flowmeter types for a range of process and operational conditions in a table that provides the user a consolidated comparative view of flow meter technology for almost every application. It is a useful tool that allows the engineer to quickly focus in on one or two technologies that will best suit project requirements.

Preview the handbook below, and obtain a copy of the handbook from a Yokogawa product expert, from whom you can also get expert level application assistance.

Flowmeter Handbook by Yokogawa from Miller Energy, Inc.

Dynamic Compensation for Static Pressure Effects in Differential Pressure Measurement

Differential Pressure Transmitter
Courtesy Yokogawa Corp.

Attaining the best available performance and accuracy from any measuring device utilized in an industrial process is always advantageous. The scale of most industrial processes is such that even small inaccuracies in process measurement produce financially tangible impact. Differential pressure measurement, with wide application in the industrial process sphere, can be improved with the addition of a means to compensate for the real world effects of static pressure upon instrument performance. Yokogawa Corporation has developed a means to dynamically compensate for static pressure effects in field measurements. The brief technical presentation below will help you understand how static pressure effects can impact your field measurements, as well as how Yokogawa’s Real-time Dynamic Compensation works to offset its impact. More detailed product and application information is available from your Yokogawa specialist.

Real-Time Dynamic Compensation for Static Pressure Effects in Differential Pressure Measurement from Miller Energy, Inc.