Many of you have written to us with substantive comments about various content within this magazine. In many cases the appropriate author has responded to you personally via phone or e-mail, but space limitations and a priority given to technical articles have led us to trim our Letters section to the bare bones.

Too bad. Many of your letters raise issues that are worth engaging for the industry at-large. With that in mind, we're going to make up for lost time by running some of the letters that came to us in 2001 and never appeared in print until now. Some may be edited to conserve space and eliminate redundancy, but we have left the gist of the messages intact.

Better late than never!

Legionella Bacteria Found in Hot Water Systems

Issue: 3/02

I read with interest Jim Olsztynski's "On the Record" column in PM Engineer's January 2001 issue. I would like to offer two comments.

First, the bacterial nature of Legionnaire's Disease is beyond discussion. It has been documented by the highest scientific standards that the disease is a type of pneumonia caused by one or more strains of pathogenic bacteria commonly called legionella bacteria.

Second, there is nothing mysterious about the behavior of these bacteria. They belong to a group called "spore-forming bacteria" that exist commonly in the environment in an inactive, non-reproducing state called "spores." They are opportunistic in nature. When the bacteria find themselves in a hospitable environment, i.e. warm water, neutral to slightly alkaline pH, plenty of nutrients, and the presence of host organisms such as algae and protozoa, they can become active and multiply. Cooling towers are an ideal environment for legionella bacteria, as are building potable water storage tanks, hot water distribution systems, fountains, hot tubs, etc.

The possible effects of phosgene in the environment are a separate issue. I am not qualified to comment on this subject. But if, in fact, phosgene in trace amounts has been detected in hvac-controlled environments, this problem should be studied and dealt with on its merits and not confused with Legionnaire's Disease.

Arthur J. Freedman, Ph.D.

Arthur Freedman Associates, Inc.

In Praise of 1.6 Gpf Toilets

Good letter from Julius Ballanco to Tom DeLay regarding Knollenberg in the August 2001 issue. Being in sales, I find that selling price has more to do with competition than with any other factor. If we have little competition, we charge a "fair" (read huge) price. If we have a lot of competition, we cry that the other guy will go broke selling at these prices and then meet the price. There are winners and losers at the manufacturer, but the consumer always wins. However, if states, counties and cities scramble a standard, there will be local standards which not all manufacturers meet. If only a few manufacturers meet the standard, prices will be higher because there will not be the price competition to keep them lower.

Funny thing is the 1.6 does work better than the 3.6, or at least that's what I've found. Here's my "proof." My wife redecorated the master bath, including a new dark gray toilet. Me being as smart as I am, I told her that white is the only proper color (maybe bone), and besides that, these "new" toilets don't flush. She did it anyway, and the new one is much better than "Old Faithful" ever was--so much so that I replaced another bath with a new one (we compromised on bone). I would replace the one in the basement, too, except no one uses it anyway.

In any case, I liked his story.

Dave Watson

Clamp Fittings Aren't New, Just Different

I read the review in the October 2001 issue by Paul Campbell of the clamped fitting that apparently was developed by inventors at Swagelok Co. The device seems remarkably similar, if not the same as a Tri-Clover or Cherry-Burrell brand of sanitary clamp fitting currently used throughout the food and pharmaceutical industries in sterile piping systems.

Am I missing something, or is this just the same thing?

Anthony J. Curiale, CPD

Supervising Plumbing Engineer

Foster Wheeler, USA

Paul Campbell's response: Thanks so much for writing, and for your interest in my column and in PM Engineer. To answer your question, I suppose the answer is all in a point of view. The inherent problem with writing about newly patented devices is that the features that make the new "invention" different enough to merit a patent are commonly not revolutionary, but very subtly evolutionary. This particular patent is just such an example. The products you mention are very similar to Swagelok's invention. However, certainly from the point of view of the experts at the U.S. Patent and Trademark Office (USPTO), the differences are substantial enough to consider this a "new or improved" device. In this case, one of the improvements, at least as it appears from reading the patent, is in the configuration of the clamp ring. While it is difficult to find this in the cryptic legalese of the patent, it seems pretty clear that these changes are not readily visible as such but are design changes to eliminate "significant galling and erosion of the nose of the thumb screws and/or the engaged portion of the clamp rings."

So, when asking if there are other products out there designed to accomplish the same type of task, the answer would certainly be yes. However, when asking if this product performs the task better, at least to some measurable degree, assuming the USPTO are the consummate professionals that I believe they are, then the answer again is yes. So, the invention is similar to other products, but not exactly the same. Now as to whether that makes this product merit a difference in price in relation to other similar products, I am certain the marketplace itself will settle that issue quickly, since all new products succeed to their appropriate level as a response to the service they give in relation to the cost they demand.

Encouraging Words About Sept. 11

As an American citizen, veteran and fellow engineering professional, I applaud the excellent article, "The Darkest Hours Are Before Dawn," that Jim Olsztynski wrote in the November 2001 issue.

The article is an inspiration that I'd like to see shared with a larger audience. Have you thought about sending it to Reader's Digest or other magazines?

Regardless, thanks for the encouraging words!

Jim Tomiser

Principal, Farnsworth Group

Critizing the Critic

I just read Julius Ballanco's October 2001 article. It contains some good criticism, which is lost completely by his use of the terms "stupid" and "stinks." Both detract from his argument and label him as less than literate.

The final draft of NFPA 5000 will be a uniform and complete document--ready for adoption and competition.

Gregory J. Cahanin Gregory J. Cahanin Fire Code


St. Petersburg, FL