An update courtesy of my alter ego BigInch:
There has been some further developments since. A criminal investigation that was opened as of Nov. Hard to believe that nobody looked at a PID before cutting in.
NTSB has also issued a Safety Recommendation in response to their initial investigations of the Lawrence disaster.
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It advises that only registered professional engineers (PEs) be allowed to work on utility facilities.
There has long been exclusions for PE requirements to work on utility installations in many states. Massachusetts being one. Texas another.
This accident resulted in my opinion from extremely bad engineering practice, well almost none exactly, plus again in my opinion, a poor design.
It also prompted me to write to NTSB.
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As a former Texas P.E, now retired, but having worked a lifetime in pipeline design engineering, construction and operations worldwide, I could not agree more with NTSB's recommendations as recently expressed in "Safety Recommendation Report: Natural Gas Distribution System Project Development and Review (Urgent)" [doc number PSR1802]. Specifically I could not agree more with the cautions that NTSB expressed therein, to use only qualified professionals and the recommendation that Massachusetts eliminate the exception requiring a competent registered professional engineer, authorized within the jurisdiction, to approve utility plans. Frankly, in my opinion, that accident was the result of complete incompetence. I would say engineering incompetence, however there appears to have been no engineer, even of minimal experience, involved at all. Alignment sheets at best show only the location of pipe and components. They do not typically show any control interrelations, as for example as would have a set of PFD and PID drawings. In fact, alignment sheets do not even show the direction of flow. Those facts alone should have been obvious even to a most inexperienced pipeline engineer and that is something I find of grave concern in itself.
I also believe the practice to which NTSB refers of Massachusetts making an exception for utility work in the face of their typical P.E. seal requirements for other types of work, and often on facilities that present a far lesser danger to the general public, is extremely common. I am sure it is not only Massachusetts that allows such serious exceptions to public safety to go unhindered. Take a look at TEXAS. Which brings me to my first question. Do you plan to advise all the state engineering license boards of the NTSB recommendation that PE seals be required for utility planning?
Furthermore I note that the resulting pressure in the pipeline damaged in the corresponding accident investigation was at some 12 X operating pressure. That makes me wonder how a pressure regulator, apparently designed to open more when downstream pressure goes low, thus increasing downstream pressure basically unhindered, came to be installed into a system where a change to plastic material and apparently a lower MAOP, would most certainly result in overpressure of that downstream piping. Such an installation would normally have to also provide at least one safety feature, if not both of the following,
1) A maximum pressure override, closing an immediately upstream block valve, set to the lowest of MAOP of the lower rated pipe, or MOP of the downstream system,
2) At least one relief valve set to the same
I would have insisted on providing both. Obviously a regulator set to open, potentially increasing pressure to mainline levels, would not have provided a safe design to supply a low pressure distribution system.
I am very much pleased to finally see movement towards actually requiring professionalism in utility design and planning. Long overdue. Thank You
Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
