Spanish Version a Hit
Ví tu reciente comentario Expandiendo Nuestra Covertura. Muchas felicitaciones por su sección en español. Así técnicos e ingenieros de habla hispana pueden beneficiarce de la excelente información que controlglobal.com ofrece. Mucho exito en tu empresa. Espero ver y participar con comentarios en los meses venideros.
Recently, I watched your Automation Minute Expandiendo Nuestra Covertura. Congratulations for your Spanish section. Spanish-speaking engineers and technicians can benefit from excellent information that ControlGlobal.com offers on online spaces such as this one. I wish much more success for ControlGobal, and I hope to see more information and participate with comments in upcoming months.
Marco A. Rodriguez PE, CAP
East Syracuse, N.Y.
More on Control Valve Simulation
The discussions on control valve simulation in the December issue were interesting, but I think they miss a major point: all these models assume a constant source and sink process pressure. In real life, this isnt so.
For example, one reason for selecting an equal percentage valve is to maintain, at worst, a linear flow versus stem position relationship, not a kitchen-faucet function, since in most installations, the wider the valve opens, the more the delta P across the valve body drops as the rest of the hydraulic (or gaseous) system components like piping, heat exchangers, etc. absorb more of the available system pressure drop. This is not a negligible effect and should be included in any realistic simulation, particularly when looking at dynamic stability.
Robert M. Green
Selling Engineering to the Kids
For years, as a member of the Roanoke Branch of the American Society of Civil Engineers, I visited local schools to exhort high school kids to consider a career in engineering; it was almost always difficult to find other engineers to go with me. Further, I proctored local MATHcounts competitions, and I was for years an ASCE-sponsored visitor to ABET, the accreditation service.
I never had a boss who didnt hold his nose over these activities. I worked as a consultant in the private sector exclusively, and there engineers are rated on productivity, the percentage of paid hours that are billableand time away to visit some college or to talk to high school kids in the name of some vague, nebulous future can put a serious dent in group productivity stats (and this years bonuses).
I imagine its even worse now that design shops are seeing work tag-teamed around the globe, 24-hours a day.
What we need, desperately, is an all-out Sputnik era-style push for engineers and scientistsand its not likely to happen.
Bob Felton, PE
Editor, Civil Commotion Blog
Wake Forest, N.C.
Whats In a Name?
I couldnt agree more with your article, Whats in a Name? in the December 2007 issue. I am an instrumentation and controls engineer and an active member of our local ISA section. One of the biggest challenges I face is explaining to other people what I do. Explaining it in a concise manner is difficult. Discussing ISA with colleagues and college students and encouraging them to join is even more difficult. Its imperative that we clearly communicate what our profession is about, and automation is the best word to do that.
Westlake Chemical Corporation
Calvert City, KY.