Addressing Premature Failure in Elastomeric Gaskets
Learn how to find clarity in the midst of NSF61 gasket confusion.
By Nicholas Pucci, Fluid Sealing Specialist - Garlock • Click here to read the original article in Treatment Plant Operator Magazine.
We’ve entered a pivotal moment in water treatment, and the challenges continue to worsen as municipalities grapple with the risk of encountering premature failure in elastomeric gaskets. Such a risk brings up several problems, including reduced efficiency, sudden equipment failure, costly maintenance and downtime, and perhaps worst of all — contamination.
Prior to 2013, gasketing products were not subject to the NSF61 (Drinking Water System Components – Health Effects) standard, leaving a critical gap in the safety and compliance of materials used in contact with potable water. However, as the demand for reusing treated wastewater grows, the influx of chlorine and chloramine levels — ensuring potability — has exposed the vulnerability of elastomeric gaskets. This has emerged as a serious issue.
In the ever-changing world of water treatment, it is important to address this challenge and explore innovative solutions to safeguard the reliability and longevity of gasketing products. This article will delve a bit into the intricacies of this issue while discussing the measures needed to navigate these new areas of concern.
For context, the industry-wide confusion regarding red rubber gaskets in potable water goes back to 2013 and before. It was in 2013 that the American Water Works Association made significant revisions to their C207 Standard — considered by many to be the boilerplate for the potable and raw water segment of the water industry. However, messaging on the changes to Environmental Protection Commissions, municipalities and general contractors was fragmented at best, with ongoing confusion as to what was NSF61-compliant and what was not.
Pre-2013, NSF61 applied mainly to molded-rubber components in valves and other equipment coming in contact with potable water. That said, over the last ten years, every significant EPC firm in the water industry segment has since pivoted to NSF61-compliant gasketing standards for potable water.
Addressing the Challenges of Increased Chlorine and Chloramines
The latest chapter of change in the water industry sector (particularly in the West) is centering around water reuse. Pure Water San Diego — the most significant water reuse project in the Western U.S. — and The WateReuse Association are two examples of groups leading the charge in this emerging industry segment.
With major municipalities needing to reuse previously discharged treated wastewater, chlorine and chloramine levels have significantly increased due to the treatment required in making it potable. As a result, more and more major water EPC firms are proactively seeking out NSF61 gasketing products with enhanced resistance to increased chloramines.
Hope in the Midst of a Coming Crisis
As of late, with the Colorado River currently experiencing historically low flow rates (measured in cubic feet per minute) there is a real concern that Lake Mead and Lake Powell will reach a critical point known as “dead pool” by 2025. The term refers to a situation where water levels in reservoirs fall below the required amounts needed to overflow through the wicket gates of the hydro plants located at these dams. Consequently, Arizona, California and Nevada could face a complete cutoff from their usual 100-year water supply from the Colorado River. Thus, the topic of water reuse is gaining significant attention.
These rising chlorine levels due to water reuse, along with the exposure of elastomeric gaskets near chlorine injection stations to high levels of chlorine, pose a significant risk of premature gasket failure. A solution must be implemented to avoid a significant catastrophe.
Thankfully, there is hope. In fact, this concern was recently emphasized in the ANSI/AWWA C111/A21.11-17 Forward Section II Sub-paragraph II.B, titled "Chlorine and Chloramine Degradation of Elastomers," which recommends the use of PTFE products such as the Garlock 3505 Stress Saver and Garlock 3505 EPIX for potable water applications compliant with NSF61 standards. These types of products ensure resistance to chemical damage caused by higher levels of chlorine and chloramine, addressing the uncertainty surrounding future chlorine levels. And in a time where change and uncertainty seem to drive clicks and dominate the headlines, lasting solutions are all the more refreshing.
About the author: Nicholas G. Pucci is a Fluid Sealing Specialist at Garlock with over 40 years of dedicated tenure. As the water/wastewater campaign lead, he brings a wealth of expertise and hands-on experience in solving complex static and dynamic fluid sealing applications. Nicholas is a graduate of Orange Coast Community College and has been instrumental in providing innovative solutions to the industry.