Tales From the Waterside
How Regular Sampling Improves Water Treatment and Saves Money By Gene Tonetti, Water Systems Management, LLC
(Editor’s note: “Tales From the Waterside” features real-life experiences as shared by water treatment experts and how they approached problems or important lessons they learned.) One of the most important and basic requirements for a successful water treatment program is proper water sampling techniques. For most seasoned water treatment professionals, this is a no-brainer; however, this topic is one that needs review from time to time. Accurate water testing cannot compensate for poor sampling technique. In addition, it is of utmost importance that a true sample be representative of actual water conditions at the time of sampling. First, both you and your customer must know where to obtain your sample(s) within the water system.
An Unexpected Visit
Let me begin by telling you a story that occurred in 1984 at a plant in southern Indiana that manufactured catheters for the healthcare industry. I made a cold call on the maintenance superintendent on a late Friday afternoon. I had no expectations of seeing him since I did not have an appointment, but I figured I could at least leave my business card and some sales literature. To my surprise, he asked me to come in and we began talking. His first question to me was, “How often should we have to replace a Schedule 40 black iron condensate return line?” I told him that I had some customers that had plants that were 25 to 50 years old and that most of the condensate lines were the original ones installed during the plant construction. I also told him that this was not always the case, but it would not be unusual to see similar pipe longevity in a plant with a well maintained water treatment program.
He said, “Well, I asked the question because we have been replacing one condensate pipe every week! I thought he was joking until he said, “We began using Schedule 80 pipe and we only have to replace the pipe every two weeks!” At that point, I knew something was very wrong. As it turned out, during my survey of the plant the following Monday, I discovered the plant was not sampling the condensate where the pipe failures were occurring. They were sampling the condensate several hundred feet away from the point of failure at a location near a large autoclave. The pH at this location was always near 8.5 to 8.8. The autoclave used 60 pounds per square inch (psi) steam. The point of failure was near a large tank of rinse water that had a submerged steamheated plate exchanger that used low-pressure steam (10 psi). The plant was using a cyclohexylamine neutralizing amine. When I tested the condensate at the rinse water tank, the pH was 5.0. The incumbent sales rep had no idea what was going on in the plant, as he had instructed the boiler operators to obtain their condensate samples at the autoclave, which is where he sampled. He was very indignant and told the maintenance superintendent he was not being fair after he found he lost the account to me after only three sales calls. That sales rep really deserved to lose the account. He obviously was unaware of the problem that cost the plant
“…I discovered the plant was not sampling the condensate where the pipe failures were occurring.”
72 the ANALYST Volume 28 Number 1
