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Dave Harrold’s article in the January issue, “Stress-Free [PAS] Retirement Planning” ably presented many practical aspects of migration engineering. It was appropriate that he used titles like “migration specialist” and “migration engineer” to describe players in this emerging field, since the discipline requires new processes and tools, in addition to planning skills. On his list of critical steps, I would suggest: 7a) Capture all software (including graphics and batch recipes) in a human readable format (MS Word/Excel/Visio, etc.) to use as a design reference during software testing and startup. This usually simple step helps resolve the inevitable disputes about how exactly the old system performed. We’ve done this on ABB MOD 300 migration projects.
I don’t normally do this, but I’m writing you to express my concern with John Rezabeck’s piece, “Intrinsic Safety Obsolete Yet?” in the March issue. I support John’s right to write it; I support your right to publish it; I cannot fathom why it might be considered useful or relevant. To my mind, it is sensational (and I don’t mean that in a complimentary way) and appealing only in a prurient way. The situations advanced by the article as evidence of the obsolescence of the requirement are too narrow and bear only a passing familiarity with the real hazards.
The article is very problematic. It makes the assumption that people are in control and are willing, able and knowledgeable enough to manage potentially dangerous situations. It is a seriously flawed assertion. The example that comes to mind is the decision to wear or not to wear seat belts: at one time, advocates of free choice were strongly against mandatory laws. However, this kind of thinking is at the very foundation of why national codes have been enacted: It is usually not possible for the average person to understand the risks, to be able to obtain the needed information (not only technical, but emission measurements, etc.), and to be able to respond effectively under all likely situations.
I once had an engineering boss who questioned my requirement for a formal lockout for a piece of electrical equipment, saying that a tag on a breaker should be okay and a lot cheaper. My response was that his kind of thinking was the reason why we had a National Electric Code (and that his suggestion was a violation).
People’s lives and fortunes depend upon safe industrial operations. I don’t believe that John’s article advanced either the understanding of good journalism nor the responsibility of journalists to confront issues and concerns. Had he really wished to do so, the article would have covered the real needs for either intrinsic safety or explosion-proofing adequately. By taking only one small aspect, distorting it to extreme and then seemingly debunking it, in an attempt to win the argument, does not rise to a level of responsibility we ask of professionals.
Although I respect Mr. Rezabek’s years in the industry, I take exception to the comments presented on relegating the technique of intrinsic safety to the ISA museum of “How We Used to Do Things” in the March issue.
There will always be Division 1 and/or Zone 0 areas that have to be taken into consideration. Declassifying or relocating equipment may reduce the requirement for Division 1, Zone 0 areas, but it will never eliminate it, and there will always be inside-the-tank applications. In addition, we all know that instruments in the field eventually have to be repaired or replaced. There are factors far beyond the control of humans (Mother Nature comes to mind) that have a negative impact on the performance and life of any instrument, especially in harsh environments. There will always be a requirement to “lift a wire” or “replace an instrument” in any installation. Processes in many installations change routinely and require instrumentation changes or additions to accommodate them.
The most prevalent form of explosion protection in North America is a mechanical protection method called explosion-proof. I would contend that it is not because it is better than intrinsic safety, but rather a “that’s how we’ve always done it” mentality. Many would argue that intrinsic safety is the safest, easiest to install and maintain explosion protection available. The fault-tolerant design criteria for intrinsic safety components substantially reduce the risk of an explosion, even under fault conditionst. Intrinsic safety is really not complex, but rather so elegant in it’s simplicity that the NEC (National Electrical Code) states that we can use the same wiring techniques we use in industrial installations in non-explosive atmospheres.
Relegating the safest, most technologically advanced and modern explosion protection technique to the ISA museum of “how we used to do things” seems a little extreme.
I’m responding to the March 2008 article by Peter Montagna titled, “Leading the Way to Process Safety.” He stated, “Let’s face it–safety costs money. Safety slows down production and reduces productivity, since people will now be involved in what might be perceived as non-value added activities.” Such statements are a myth that should not be allowed to stand.
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