Designer’s Notebook for May 2010 Issue
Mr. Messina hit one out of the park with his evaluation of Value Engineering. I too agree that VE is a wasted effort when the project calls for either quality equipment or design. The best line regarding VE came from Chicago Engineer Dick Kviz…”I Value Engineered the project when I designed it…afterwards call it what it is …Cheap!”
Value Engineering: What Is It?
Mr. Messina, I liked your last paragraph best. Competent engineers don't need "value engineering," because they practice it continually. The problem is that a value engineering team cannot make a poor design into a good one. When I graduated, it was assumed, and rightly so, that a green graduate needed mentoring and training to become a functioning engineer. Unfortunately, primarily because of financial pressures, today these green engineers are assigned to projects above their "pay grade" and instructed to meet a minimum level of billable hours with little, if any mentoring. I'm sure you remember Compressed Air Magazine as fondly as I do. It served no direct beneficial function, so it became extinct. It stimulated creative thought, what a novel concept.
Carr Baldwin, PE
Laboratory Plumbing 101, PS&D April 2010
Jim Williams, I read and enjoyed your article on Lab Design very much. I am a retired Plumbing Design Engineer (now a NJ State licensed Plumbing Subcode Official/Inspector in the township where I live) and I agree with all your suggestions and reasoning for good design practices. Let add a few extra “red flags” to be aware of, during your design: Listen to and understand the people who will be actually using these lab facilities, then explain your design methods and reasoning to them, as though they were 6 years old. Emphasize the importance of how these systems and equipment must properly be used, your pipe material selection and pipe sizing reasoning. Find out the true concentration levels of chemicals that will be used, then add a safety factor of 20%. Certain pipe materials are only good for low amounts of certain chemicals. Check the chemical resistance charts of all the pipe materials selected, then give a copy of these charts to the client for reference and to CYA. Check the proper pipe joint methods and materials used, e.g., type of gaskets and their approval rating for such chemical applications. Check proper supporting of these pipe systems…very critical. Visit the site at selected intervals during construction to check on the proper methods of installation…a progress report/check. Any contractor change of piping material, devices, valves, equipment, etc. MUST first be approved by the Plumbing design engineer…PERIOD. These are just a few items that I have run into during my 34 years of Plumbing design/engineering….now I am witnessing these again as an inspector.
Gerald Recigno, CPD
Conducting a Plumbing Field Survey
I would like to comment on James Stenqvist’s April article “Conducting a Plumbing Field Survey.” The checklist was quite complete except for one item, the piping material for any of the plumbing systems. It is important to identify the materials so as to determine the condition and if that material will be compatible with any new system renovation. Many years ago a Survey Report was prepared by a consultant for one of our older campus buildings, anticipating a major seismic up-grade project. The report stated that the domestic hot and cold water piping systems were threaded galvanized steel pipe. The report assumed that the condition of the pipe was very poor and should be replaced. The building was built in 1934 and never re-piped. A red flag went up. I did not think a steel pipe system would have lasted that long. All of the exposed piping in the building had been painted many times, so the original pipe finish was not apparent. I did a field test with penknife and file, removed some paint, and found Brass pipe with Brass screwed fittings: a better material by far. We had our campus plumbers remove sections of pipe for inspection. The interior of the pipe was as clean as the day it was installed. When the renovation project was designed, much of the original water pipe was left intact. The material for those sections that were required to be replaced, and any new pipe was K copper.
Steve Sebolsky