CM-03:   Someone To Blame Reducing Your Legal Liability By Actively Monitoring For Corrosion Activity The corrosion of HVAC piping systems and their related equipment presents the most potentially damaging losses to any private, industrial or commercial property next to the threat of fire.  Direct losses exist in pipe repair and replacement costs, but often the most far reaching losses are in the form of litigation due to water/property damage and lost productivity.  Some of the most damaging pipe failures we are aware of have shut down entire high rise office buildings, or caused extensive damage to multiple floors of tenant space. Where a building property has the responsibility of providing basic heating and cooling services as part of their lease contract, the failure of any large and pressurized piping system, especially where significant water damage is concerned, means a very expensive repair and damages bill for those responsible. Chemical Treatment No Guarantee Methods to minimize corrosion and monitor its severity exist, but do not necessarily guarantee trouble free service.  Corrosion caused leaks can occur even though top quality water treatment is provided,…

CM-02:   Extending Service Life Evidence That Good Corrosion Control Is Possible By Following Certain Guidelines Pipe corrosion is a major problem for building and industrial properties, and totals billions of dollars in losses for the United States alone.  Our new corrosion monitor CorrView ®, as well as our ultrasonic testing services and the majority of this website, is focused toward the monitoring and remediation of corrosion related problems. As the content of our website clearly illustrates, corrosion is a significant threat to any building operation, and can produce problems ranging from mild annoyance and small repairs, to major failures and millions of dollars in damage and replacement costs.  Such corrosion problems seem to be on the increase for virtually all piping systems. Proper Planning Necessary Most corrosion problems begin before the water ever enters the pipe, and advanced planning is a key element to a long running and properly operating piping system.  Appropriate filtration to an open or closed cooling system is today a necessity, rather than an option.  A well planned and executed chemical treatment program including fully automatic feeding equipment…

CM-05:   Corrosion Coupons A Case History Of Where The Reliance On Corrosion Coupons Concealed A Serious Corrosion Problem For Years Our extensive volume of work in the field of ultrasonic pipe testing has overwhelmingly documented the accuracy and reliability of this testing process, as well as its ability to provide more valuable information than any other pipe testing method typically employed.  Combined with proper data analysis, and given sufficient test points, ultrasonic testing (UT) provides an excellent overall evaluation of pipe wall loss, corrosion rate, and remaining service life. A frequent conflict exists, however, when comparing corrosion rates from new metal coupons against corrosion rates estimated from actual wall loss measurements.  In virtually all cases, reported corrosion coupon rates will exist far below those calculated based upon actual wall thickness loss – often with the corrosion rate for coupons showing 10% or less of the true wall loss occurring.  Where questions arise, independent testing in the form of a metallurgical analysis will confirm the accuracy of ultrasonic testing over corrosion coupons in every case. Unfortunately, corrosion coupons have been in service for so long…

CM-01:   Misleading Information The Inherent Inaccuracy And Limitations Of Corrosion Coupons Corrosion coupons are the most widely used form of corrosion measurement and monitoring today.  They are precisely machined thin bars of various metals which are inserted into an external “rack” or layout of 1 in. piping to the main circulating loop.  A large variety of metal alloys are available in various physical configurations, although for HVAC and process cooling applications, rectangular bars of mild carbon steel and soft copper are the primary materials used. In most cases, the pressure differential across the suction and discharge of the circulating pump is sufficient to flow a small side stream of water through the external coupon rack.  This flow rate is regulated based upon various procedural guidelines in order to ensure uniform conditions between tests.  At a few feet per second, however, it never approaches actual flow conditions within the piping system.  Where no flow exists, such as at dead legs or by-pass crossovers, corrosion coupon testing is generally not pursued. Typically, the external rack is configured to allow the simultaneous testing of two or four…

CM-04:   Testing Alternatives The Many Benefits Of Spool Pieces In Monitoring Pipe Corrosion For most property owners, managers, or plant engineers, a corrosion monitoring program exists for the primary purpose of verifying the effectiveness of the chemical water treatment contractor.  Although a performance standard is rarely established or held to, corrosion coupon results are generally used in deciding if any changes should be made to the treatment program, and of whether a corrosion threat exists. Since corrosion coupons typically return favorable results given their isolation from the main piping system, they more often provide steady reassurance that conditions are acceptable, and that there is no need for further concern.  Rarely do corrosion coupons show true system conditions, or provide a critical look at corrosion control effectiveness.  Often secondary in importance is the interest to track the accumulated metal loss from the piping interior, gauge its remaining service life, check for deposit build-up, and judge whether interior pipe conditions are improving, declining, or remaining static. Different Test Methods Available Corrosion monitoring is fulfilled to varying degrees of success through the use of different…