ENSURE PROPER INSTALLATION OF LEVEL INSTRUMENTS
I read with interest a fine paper by Dr. Summers on the risk of overfilling [www.ChemicalProcessing.com/articles/2010/143.html]. Let me please share the following for your consideration. Some of what follows is a corollary to what Dr. Summers has pointed out in the "SOLUTION" section of her paper —
Item 6: "Determine the technology ……." (p. 33, August 2010).
Along with the technology for level measurement, (e.g., dp cells, radar, capacitance, or many others) proper installation of instruments also should be emphasized. It would not be surprising to find some plants where instrument installation is an "unguided" activity, i.e., there are no procedures for proper installation. Instrument technicians rely on their experience or learn by on-the-job observations of their co-workers. It is conceivable that poor installation practice could prove to be a "weak link" in efforts to ensure a safe system.
In my view, well-written installation procedures (or guidelines) — not only for level sensors/transmitters but for all instruments — would serve two broad functions: they (procedures) will minimize failures resulting from a poor installation and will help train younger instrument technicians.
Finally, a positive note on the methodology for applying instrument systems: The comprehensive practices recommended by ISA 84.00.01-2004 (or IEC 61511) for Safety Instrumented Systems (SIS) follow a system's approach along with safety life cycle philosophy. These approaches collectively help minimize instrument failures, including those for level measurement, and can be applied to the basic process control instrumentation as well.
ENGINEERS WOULDN'T FIT IN CONGRESS
[This letter is in response to the September editorial "We Need More Engineers in Congress."] In my opinion, I think the reason few engineers want to be involved with current politics is that truth and logic rarely are used to make decisions, at least that is the view from those of us on the outside.
In Washington, deals to support others' pet projects in order to gain support for your own pet projects seems to be the norm.
It is rare to see any elected official (local, state or national) do "what is right for the country" if it does not gain them personal favor with their constituents.
I agree that term limits may delete a lot of memory and knowledge from Congress, but it would also force a global outlook for all members since there would be a limited time to be effective. Also, the elected officials would not spend the majority of their political career working to maintain their political career (as it is now) but instead spend time trying to do some good for the country.
Why would any logical, reasonable person (which I think describes most engineers as well as a lot of others) want to be involved in a profession that is highly criticized, blatantly out of step with the normal man, and that is usually rated with the lowest positive ratings of all groups?
Paul D. Douglas,
JULY'S PUZZLER DESERVES MORE ATTENTION
I know that this comment is a little late, but having just read my July issue of CP … I am somewhat concerned that actions to address the problem discussed in the Puzzler [www.ChemicalProcessing.com/articles/2010/117.html] not lead to undesirable or even unsafe conditions.