Regulatory modifications in 2010 have raised important issues in design and use of industrial safety systems. Certain changes in IEC 61508, now being widely implemented, mean that designers and users who desire full compliance must give new consideration to topics such as SIL levels and the transition from 1H to 2H methodologies.
Information about the health of a control system, the I/O systems, field devices and final control elements can be critical for plant operation and uptime. Timely diagnostic information can mean the difference between a quick repair and hours or days of unplanned downtime.
The limitations of traditional electric actuators have an impact on the life of the system. The most common problem is exceeding the rated duty cycle, causing the motor to burn out. A study done by ExxonMobil and presented in October 2012 at Coking.Com identified wear issues. Download this white paper to learn more.
For decades, process instrumentation specifiers have faced the decision whether to use a mechanical switch or a continuous transmitter for a given application. Either type of instrument can be used to effectively control industrial processes and protect equipment and personnel -- and each has associated pros and cons. Application specifics typically drive decision-making, dictating which approach is most effective from performance, cost and lifecycle support perspectives.
This paper will address the application of Guided Wave Radar (GWR), also known as Time Domain Reflectometry (TDR), in your steam loop. Included will be discussions of how this technology functions and differs from more traditional forms of level indication.
The heart and soul of any boiler based power generation system is the steam loop or circuit. Without the proper availability of water in this system, efficiency suffers. In more extreme circumstances damage to other components from either too much water (carryover) or too little water (low water condition) will occur and shorten a boiler's lifespan. In the most extreme situation a dry fire accident could occur resulting in severe damage and personal injury.
Level indication in the steam loop is critical, yet the methods employed to measure it have been slow to evolve or change. Some of that has been due to code requirements (PG-60 of the ASME Boiler and Pressure Vessel Code) or a simple lack of confidence in "new" technology. It has only been in the past 15 to 20 years (recent in terms of boiler/steam loop history) that technologies such as magnetic level gages or differential pressure devices have been used in place of direct reading glass gauges on applications such as feedwater tanks, high pressure preheaters or hotwells. These same devices are now utilized for drum level indication as well. The most recent addition to the technology basket for steam loop applications has been Guided Wave Radar. Used in conjunction with other technologies it is seen as a reliable cost effective choice for redundant level measurement in all steam loop applications, including drum level.
A new generation of low-power valves has broken through the old paradigm of power consumption in the chemical processing industry. A new report on these products will interest both OEM and end-user designers specifying solenoid valves for chemical processing applications.
Tapping the expertise of manufacturers at the forefront of low-power valve technology, the report explores how innovation is offering new possibilities -- and challenges -- via topics such as integrated solutions, clogging, usefulness in point-to-point and bus networks, cost savings, remote applications, and relevant industry standards. It suggests which characteristics buyers should seek out in selecting the newest -- and most consistently dependable -- low-power valve technologies.
Equipment designers frequently must incorporate miniature solenoid valves into their pneumatic designs. These valves are important components of medical devices and instrumentation as well as environmental, analytical, and similar product applications. However, all too often, designers find themselves frustrated. They face compromise after compromise. Pressure for increasingly miniaturized devices complicates every step of the design and valve selection process. And missteps can wreak havoc. How do designers balance the needs for reliability, extended service life, and standards compliance against often-contradictory performance requirements such as light weight, high flow, and optimum power use?
This report consolidates the expert views of designers and manufacturers with wide experience applying miniature solenoid valves for myriad uses across multiple industries. It presents a true insider's guide to which requirements are critical for common applications. It also highlights new valve technologies that may lessen or eliminate those troubling compromises.
This initiative is the first step in filling a noticeable void in industry - the lack of independent competency training in the Operations Management (MES/MOM) arena. This lack of wide-scale competency is recognized as a major barrier to plant and supply chain optimization and global operations excellence.
With members in 85 countries globally, MESA is an independent, objective community of like-minded people and enterprises working to make Operations more reliable, capable and profitable. Some of the foremost experts across the Operations Management landscape are leading the knowledge sharing within the MESA community by offering programs across 4 continents by mid-2011.
MESA Certificate of Competency (CoC) for MES/MOM* Methodologies: A 4-day, comprehensive program of MES/MOM Methodologies courses aimed at Systems Analysts, Architects, Programmers, Project Managers and Consultants.
MESA Certificate of Awareness (CoA) for MES/MOM Business Awareness: A 2-day, high-level program of MES/MOM Business Functions courses geared for executives, manufacturing/operations and IT personnel and sales professionals. The CoA courses are higher level, short versions of the CoC program.
New electric control-valve actuators provide significant control and reduced variability benefits over compressed-air actuators in a wide range of process applications, resulting in superior control performance, fewer maintenance problems and energy savings.
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.
During recent decades, rotary control valves have encroached upon the traditional territory of the linear globe valve in the petrochemical industry. Eccentric plug valves in particular have established a firmfoothold in petrochemical applications. Ever increasing emphasis on environmental issues has meant that petrochemical companies are paying increased attention to emissions coming from control valves. This trend has made rotary valves more attractive because rotary valves typically have lower gland emissions than globe valves. In addition to low emissions, eccentric plug valves have proved to be suitable for numerous applications. Typical applications and opportunities, including their uses in the petrochemical industry, are considered.
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.
In this paper, a model predictive controller is configured to simultaneously manipulate a small valve and a large valve, eliminating the problems inherent in split-ranged and valve-position controllers.