CM-07:   So What’s Wrong With This Picture? This Is Not What A Corrosion Coupon History Of 0.4 MPY Should Look Like At A 6 Year Old Condenser Water System Actually, the above picture is not wrong this time! Forty years of involvement in the business of investigating, monitoring, and reducing corrosion related losses to commercial building properties has resulted in certain well documented and irrefutable findings. Our ultrasonic inspection of 1,129 building properties in 252 cities across the United States, addressing 2,961 piping systems, 63,796 individual sections of pipe, and the taking of 4,919,955 wall thickness measurements, substantiates our experience and authority in this field. Increasing Losses Corrosion is the second most serious threat to any facility or building property next to fire – yet far more likely to occur. With pipe corrosion losses on the rise, the reliable and accurate monitoring of any corrosion control program becomes critical to efficient, reliable, and trouble free operation. Yet in most investigations, we find that it is not the absence of a corrosion monitoring program which is…

PD-14:   Dead Zones The Leading Cause Of Major Pipe Failure At Condenser Water Systems Open condenser water systems inherently exist under a significantly greater corrosion threat. Even though they typically consume the bulk of any chemical water treatment budget, they still fall victim to the majority of corrosion related problems and piping failures. Despite significantly greater efforts and expense to control corrosion through highly automated chemical feed and bleed systems, water filtration, computer monitoring, and independent corrosion consultants, we have documented a growing incidence and severity of system failures which arguably should never have occurred. Issues Misunderstood Multiple factors influence such higher deterioration of condenser water systems, but are rarely addressed adequately through either their design or operation. Issues such as lower quality and undersized pipe, for example, cannot be controlled. Corrective measures incorporated into most open systems, whether they are proactive or in response to a specific problem or pipe failure, are often inadequate or even worthless; believed to work based solely upon speculation, unsubstantiated claims, anecdotal belief, and/or questionable science. Elsewhere, it is an absence to the understanding…

CP-04:   Closed Piping System Corrosion Avoiding A Problem That Should Never Occur Of the many corrosion problems that plague a typical building property, corrosion at a closed HVAC piping system should never occur. Fundamentally, corrosion impacts different piping systems in different forms and at widely varying rates.  Other than protective coatings or pipe lining, little can be done to control corrosion activity at plumbing, sanitary waste, and domestic water systems.  Some options are available for fire sprinkler lines but rarely employed. Dry fire sprinkler systems experience far greater and more advanced failures than wet systems.  Steam systems are less impacted with very uniform wall loss; while steam condensate lines always suffer greater corrosion threat due to deep pitting.  Condenser water service typically requires the closest attention and highest chemical cost expenditure, with results widely dependent upon many different factors. For many piping systems, layout, design, corrosion protection ,filtration, and especially materials of installation will play a significant role in its future service. For a closed piping system such as hot water heating, secondary, closed condenser water, chill water, dual temperature, reheat, or other service,…

CP-02:   Unknown Corrosion Influences Why Pipe Failure Is Not Always The Fault Of Your Water Treatment Provider One of the most critical responsibilities of any property owner or manager is maintaining their various HVAC piping systems.  This requires strict preventative maintenance, and for most HVAC systems, an effective chemical water treatment program. Properly maintained and protected, most HVAC piping systems will last far longer than the expected service life of the building itself.  For standard 12 in. condenser water pipe having an initial wall thickness of 0.375 in. and a minimum acceptable thickness limit of 0.150 in., maintaining a uniform 1 MPY corrosion loss will easily provide over 200 years of reliable service. At 5 MPY, service life is reduced to 45 years, and at 10 MPY – 25 years or less.  Quite clearly, effective chemical protection, or the lack thereof, plays a very critical role in any building’s operation. In fact, we often document outstanding corrosion control in our ultrasound based piping investigations.  Such as extra heavy 24 in. condenser water pipe from 1958 found still at 0.485 in. and near its new…

CP-01:   Contradiction In Terms Why Open Condenser Systems Are Provided Lower Chemical Protection Than Less Critical Closed Systems Open cooling tower systems are well recognized as existing under much greater environmental stresses, and therefore traditionally suffer a greater corrosion loss.  Compared to a closed chill water or secondary piping system which will typically show a 1-2 mil per year (MPY) or less corrosion rate, open systems generally range from 3-5 MPY to well above.  Today, corrosion rates are commonly found at above 5 MPY – with some examples capable of reaching to 25 MPY or above. In addition to a difference in wall loss and corrosion rate, closed systems rarely suffer the more severe corrosion attack caused by microbiologically influenced corrosion (MIC), under deposit pitting, and galvanic corrosion between dissimilar metals.  While a severely corroded closed piping system may show a 5-8 MPY corrosion rate, severe problems at an open water system can produce corrosion rates exceeding 50 MPY. Many Reasons Exist Clearly, many forces are at work within different types of piping systems to create such variances in corrosion rates.  Some…

CP-03:   Extending System Service General Recommendations For Maintaining Good Corrosion Control in HVAC Systems Advanced corrosion of steel piping systems has become a serious and expensive problem to many facility managers and plant engineers.  At a growing number of commercial properties and process plants, high corrosion rates have forced the replacement of critical piping systems – some within a short period such as three or four years.  At others, it has created loss of service, equipment damage, excessive maintenance demands, high energy costs, major repairs, and overall unnecessary expense. While lower quality pipe and restrictions on the use of specific corrosion inhibitors and biocides have clearly contributed to the problem, it remains a fact that many building properties and plant facilities regularly maintain open system corrosion levels in the 1 mil per year (MPY) and below range.  Excellent corrosion control and high operating efficiencies can, in fact, be achieved by carefully evaluating current operating conditions and implementing certain precautionary, and often necessary, changes.  Careful corrosion monitoring is critically important. Good Corrosion Control Possible In order to prevent the damaging effects of uncontrolled…