Cybersecurity / Intrinsic Safety / PLCs & PACs / Safety Instrumented Systems

Top 10: Best of "Ask the Experts"

In this article, we review some of the best questions submitted to our experts throughout the years.

By Katherine Bonfante

Every month, our printed magazine features "Ask The Experts," a section dedicated to readers looking for expert and free of cost advise from industry leaders. Our process control authority and Control Columnist Bela Liptak takes the time to read through each submitted question and answer it himself. He also consults with other industry experts with whom he has worked with, while writing the Instrument Engineers' Handbook, Fourth Edition.

This article gathers the top ten questions our readers found most informative. Read through them and if you have a question you need an expert answer on, consult our experts.

CG1501 ATE B1

What Is the Proper Role of Automation?

Automated system can lead to more and more complexity and confusion. Until the instruments, automation and controls get extremely reliable, we'll still need to keep humans in the loop.

CG1501 ATE B2

Controllers: Direct vs. Reverse-Acting Control

Valve failure position and controller actions are independently determined. In this article our experts tackle them separately.

CG1501 ATE B3

PLC Redundancy- How Much is Enough?

Is PLC processor redundancy worth the engineering cost and maintenance cost? What device should I use to measure flow of liquid sodium in hazardous environments?

CG1501 ATE B4

Can Process Control Prevent Oil Well Blowouts?

Oil drilling accident in the Gulf of Mexico: What caused it? Could we have prevented the blowout with properly designed process control systems?

CG1501 ATE B5

Aviation Safety; Variable Control Valve Failure

Does better understanding of process control could help determining the probable causes of aviation accidents?

CG1501 ATE B6

Solar Power Plants, Orifice Vent Holes, District Heating

Readers ask: When and where is the first solar-hydrogen power plant being built? What is the use of vent hole in the orifice plate? How to upgrade buildings' heating systems from "Leningrad Design" to a current design?

CG1501 ATE B7

Three-Mile Island, Preventing Boiler Blowups and More

Learn more on the Three Mile Island accident

CG1501 ATE B8

How to Measure pH Inside a Tank; Increasing Scan Times

A reader wants to know about pH measurement and control systems for a biphasic (organic-plus-water-based) reaction, while another one wonders if there is ever a reason to lower the frequency of execution of the PID execution in scanning controllers (in other words, scan the PID instruction less often by increasing the loop update time).

CG1501 ATE B9

Features and Capabilities of Hybrid Controllers

Is there a difference between a DCS and a hybrid control system? Bela Liptak and his cadre of automation experts suggest where to apply each technology in this installment of Ask the Experts.

CG1501 ATE B10

Failing Safely with Shutdown Systems

This month's edition of Ask The Experts focuses on a reader's need for clarification of international standards for the design of a gas and fire shutdown system for offshore oil and gas platforms.