PI-11:   Pressed-On Copper Connections The Acceleration of a Common Failure Mechanism for Copper Pipe? Copper pipe has traditionally been viewed as trouble free for building services applications such as plumbing and HVAC.  Corrosion resistant, long lasting, easily to handle, and faster to install.  Copper pipe has enjoyed widespread use for over 100 years. While copper pipe is susceptible to various failure mechanisms caused by acidic conditions, micro-fine pitting, microbiologically influenced corrosion (MIC), erosion, cavitation, galvanic pitting, and others, such issues have generally been of limited concern.  Additional factors exist such as water quality and surprisingly enough its level of purification – with exceptionally pure water such as produced by reverse osmosis creating highly aggressive corrosion conditions. System design, flow velocities, its manufacture, cleaning and commissioning, upstream steel components, along with water quality and temperature can, either alone but mostly in combination, produce randomly isolated and difficult to predict failures. Although uncommon, we encounter such isolated issues in our ultrasonic (UT) based evaluations of copper piping systems, and frequently turn to metallurgical lab analysis in order to microscopically identify the precise cause. Common Threat The…

PD-13:   Infrastructure In Decline The Steady Decline In The Quality Of Today’s Piping Products Means The Potential Of Serious Corrosion Problems Often Despite All The Precautionary Measures Taken The scenario is unfortunately all too familiar. A concerned phone call describing widespread pipe corrosion or failure, even though every standard and industry accepted action had been taken to avoid such event. In many instances, additional precautions such as automatic water filtration systems, extensive chemical feed controls, and chemical / corrosion monitoring had been implemented. For some others, third party corrosion consultants monitored every fine aspect of the water treatment program. Yet for many, none of their actions made any difference and failures still occurred. While lacking, inadequate, or poorly administered and maintained chemical water treatment programs clearly exist in many examples, the majority of corrosion problems develop despite evidence that corrosion control had been a high priority item. In reality, chemical water treatment companies and their representatives have a strong underlying interest to provide the finest service possible for every client – thereby extending their contract past just the first year. Results, however,…

PI-10:   Infrastructure In Decline The Unknown Impact of Lower Quality Pipe to America’s Real Estate Industry In comparison to the rest of the world, most American buildings are really not that old.  Even in our earliest Eastern coastal cities like New York, Philadelphia, and Boston, the overwhelming majority of our commercial office buildings were constructed post World War Two. Not until the invention of steel beams and elevators in the late 1850s did many structures ever reach beyond seven floors.  CFC based air conditioning, which finally introduced comfort to the workplace, only started being installed at high rise office buildings and other commercial properties in the early 1950s. According to various New York City real estate authorities, the average Midtown-North commercial office building is just 70 years old.  The average Midtown-South office building is far older at 105, and for Downtown, the average age is 76 years. Former Standards Without question, our older structures have held up exceptionally well over time.  In terms of piping alone, the much higher quality and inherent corrosion resistance of older pipe, heavier pipe schedules,…

PI-08:   Corrosion The Beginning How Secondary Mechanical Problems Can Originate From A Simple Pipe Corrosion Condition It would be impossible for a failure at a section of main condenser water riser to go unnoticed for more than a few minutes.  A blown off fitting at even a 1 in. medium pressure line would produce hundreds of gallons of water – causing it to be quickly located and addressed.  In contrast, much smaller leaks, depending upon their location and severity, can produce severe secondary problems that can easily avoid detection.  In certain instances, a smaller leak can actually create greater damage than one which is much larger. A leak at a threaded connection, often the very first sign of a pipe corrosion condition, may exist for years prior to producing enough water to signal a problem.  Often located behind walls, in shaftways, under floors, and above ceilings, thread joint failures can slowly leak water into area surroundings to corrode other piping systems, metal supports, electrical services, and other equipment.  The extent of the damage is usually detected only once the leak extends past its immediate…

PI-07:   Mold How A Minor Corrosion Problem Can Quickly Evolve Into A Building Wide Health Threat Most corrosion problems, if they result in a leak or piping failure, are quickly addressed in the form of repair or replacement.  Significant property damage can result from the failure of even a 1 in. diameter line under moderate pressure, although in most cases the failure is quickly addressed. Where the pipe leak is a one time occurrence, any remaining moisture hidden behind the walls or within ceiling and floor areas is soon evaporated and dissipated, and the area returned to its normally dry state.  This is especially true in air conditioned office building environments, or in areas where low humidity levels are normally maintained. Ironically, an entirely different threat to building operations is created for the opposite corrosion scenario where the smallest water leaks occur.  Such conditions commonly exist for the more mild corrosion conditions, or for early stage corrosion problems that do not produce significant enough water volume to warrant immediate attention.  In the photographs below, slow leakage through the thread may have existed…

PI-06:   A Hidden Threat The Severe And Hidden Danger To any Condenser Water Piping System Which Is Annually Drained Down There is a general understanding by those working within the building operations, plant engineering, and water treatment fields that drained carbon steel pipe will corrode to a higher degree than pipe which is always filled with water.  This produces a tremendous vulnerability to the piping system, and one which is typically hidden from view. While the actual degree of wall loss for drained pipe is in most cases undefined and only speculated upon, a presumption that it does exist often prompts preventative action.  For those responsible for the operation of building or plant properties in Northern sub-freezing climates, freeze protection for less than 24/7 operations is required – thereby introducing new corrosion concerns as well. Corrosion Activity Varies Such wall loss varies greatly, and is, unfortunately, far from being predictable.  Pipe which is drained and left in a wet condition has been documented to corrode at as much as 10 or more times the rate of pipe left filled with…

PI-05:   Infrastructure Failure Pipe Corrosion And Its Growing Threat To Office Building And Plant Operations The corrosion of steel piping and its related components is a continuous and virtually unstoppable process.  Even with the application of available countermeasures, pipe corrosion exists as one of the most potentially damaging threats to any private, industrial, or commercial property – second only to fire. Corrosion activity affects HVAC piping systems to varying degrees generally dependent upon the piping service, quality of the steel, age, its size and layout, joining method, chemical treatment protection, engineering design, and the specific corrosion mechanism involved. For many properties, the net result is an added maintenance problem, greater energy costs, unnecessary threat and liability, property damage, high remediation expense, and in the most extreme examples – the need for partial or total pipe replacement. Common Corrosion Examples Multiple photo galleries are provided on this site related to individual corrosion conditions as well as the specific corrosion characteristics related to different piping systems and tanks.  Please visit our Photo Galleries. Once well established, most serious corrosion conditions are difficult,…

PI-03:  Corrosion Under Insulation (CUI) Or Is It Actually Corrosion Under Inadequate And Poorly Installed Insulation – CUIAPII? As any building property ages, certain problems, nonexistent or unforeseen decades earlier, emerge.  Chilled water and other cold steel piping systems are especially vulnerable to external corrosion, which can easily exceed the internal corrosion activity of even the most poorly chemically treated system. Corrosion under insulation, or CUI as it is formally termed, is also a threat to any carbon steel pipe located outdoors, and where the insulation is intended for either freeze protection or to shield it from exposure to the elements.   Although further protected by an outer vinyl or metal jacket, corrosion under the insulation frequently occurs.  No CUI threat typically exists where copper or brass pipe has been installed, although the wet insulation itself is a common substrate for mold to grow and thrive.  Galvanized steel pipe, depending upon its quality, is generally under minor threat from this external corrosion problem, although it can develop. Greater Threat To Cold Piping Systems For steam, steam condensate, and hot water heating…

PI-04:   Dual Temperature Piping Systems A Serious Hidden Threat Due To An Engineering Design Oversight From More Than 40 Years Ago  From a corrosion perspective, every piping system exhibits certain characteristics in terms of wall loss, the potential for failure, and impact to building operations.  Those characteristics are further influenced by engineering design, materials used, insulation, chemical protection, temperature, and maintenance, among other variables. Pipe Service Life Varies A brass domestic cold water system can last 100 years, as can an extra heavy cast iron storm drain line.  Chill water, hot water, and other closed systems should provide 65 years of service.  Wet fire sprinkler systems can easily last 75 or more years.  Condenser water pipe can provide 60 years of service at the larger pipe; 20 years at the smaller threaded sizes, if provided effective chemical treatment.  Proper maintenance is always an important variable in obtaining long pipe life, along with initial pipe quality. Many piping systems were designed based upon certain assumptions into the future which have proven reasonable and correct.  The use of extra heavy or schedule…

PI-02:   Roof Level Corrosion Avoiding Some Obvious But Surprisingly Common Problems Most building operators see the first indication that a corrosion problem may exist through evidence shown at the roof level.  Some problems may be as minor as a pinhole leak or a failed thread – while others may cause the loss of a major riser.  Problems may be hidden at the pipe’s interior, concealed within the insulation, or as obvious as a trail of rust flowing toward the roof drain. In many instances, suspected wall loss finally becomes obvious by the presence of iron oxide deposits and chip scale in the cooling tower sumps and overhead distribution pans.  Rust and corrosion at the pipe exterior may also be noticed in areas directly exposed to the elements, or more frequently, may exist hidden under the pipe insulation and hard outer metal covering. Dual Corrosion Attack Roof level pipe typically suffers a two front corrosion attack.  If it is drained down partially for winterization in sub freezing climates, higher corrosion rates by as much as 6 times or more above those existing at…