The Cooling Technology Institute (CTI) has published the first of what will be a series of standards to provide guidelines for the improved operation and maintenance of cooling towers and associated equipment. The first set of standards deals with corrosion testing coupons. “Some people believe coupon testing is invaluable and some believe it is almost useless,” said Ashland Specialty Chemical Company’s Dr. Phil Grayson, moderator of a panel discussion on corrosion at CTI’s annual conference in Corpus Christi, Texas. “The truth depends on how you use them. That’s why we have developed the standards. If followed, corrosion coupons will be a valuable testing tool.”
Providing an overview of the new standards was Art Brunn, retired DuPont senior water treatment consultant, task group member and primary author of the new coupon standards. “Consistency is the key to how useful coupon testing is,” said Brunn. “These standards tell us how to make sure everything is done the right way and the same way every time.” The new document, STD 149: Standardized Corrosion Testing Procedure – Corrosion Coupon Testing & Test Procedures addresses all elements of testing with coupons. The document defines precise standards for the coupons themselves and provides a standard design for the racks in which they are placed during exposure. Preparation, exposure time, handling, shipping, evaluation and record keeping are all addressed in detail. “If operating staffs follow every detail of the procedures, coupon testing will give you a pretty good idea of what’s going on in your cooling system,” said Brunn.
Formerly known as the Cooling Tower Institute, the CTI Water Treatment Committee’s standards task group will be developing additional operating and maintenance standards over the next several years. The group has identified monitoring and control of microbiological fouling and monitoring and control of inorganic fouling as practices for which it will develop standards and procedures.
A copy of the corrosion coupon standards can be obtained for $10 from the CTI office, web site www.cti.org; phone (281) 583-4087 or by mail at P.O. Box 77383, Houston, Texas 77373.