Photo Gallery Series E:  Tanks And Pressure Vessels Storage tanks and pressure vessels play an integral role to all piping systems.  Due to their different designs, a wide range of corrosion related concerns exist.  Above all, any tank or pressure vessel having a varying water line, such as for domestic water storage or an expansion tank, will experience noticeably higher corrosion and pitting between its high and low water levels.  The failure of any pipe leading to or from a tank or pressure vessel should always prompt a concern for its condition. Pressurized vessels are at a far greater threat than for unpressurized tanks, with examples such as deadly explosions at compressed air storage tanks all too frequent.  As always, the much older water storage and pressurized fire sprinkler tanks were constructed of heavy 1/2 in. steel plate.  Yet today, that wall thickness has been substantially reduced.  Any old water storage tank installed prior to 1940 has likely been internally coated with red lead paint and/or coal tar for corrosion protection – both major health issues requiring abatement. While most ultrasonic investigations relate to water storage due to the potential for large scale damage and service interruption, ultrasonic testing is…

Photo Gallery Series D:  Insulation Insulated pipe comprises some of the most widespread and costly corrosion issues we investigate.  Not only are the piping layouts complex and extensive, they are typically enclosed behind walls and in ceilings.  While insulated pipe failures are primarily related to chill water and dual temperature systems, it is also common for condenser water and other insulated pipe in exposed outdoor environments.  Fundamentally, any corrosion occurring to the exterior of the pipe is the fault of inadequate insulation thickness, the wrong insulation type, the lack of an effective moisture barrier or outer protection, having been poorly installed, or it being trampled on for years by workers and not maintained. The common misconception that insulation alone will prevent any corrosion to the pipe surface is one major cause of the problem; with the very simple 1st step of coating the pipe with a rust preventative never even considered.  A 2nd misconception is that the outer paper covering of typical fiberglass insulation provides a barrier to moisture migration.  As an inevitable result, moisture migrates through the insulation to produce varying degrees of deterioration from mild cosmetic surface rust all the way to total pipe destruction.  Most conditions remain…

Photo Gallery D8:  Poor Insulation Installation Poor insulation installation is perhaps the most preventable form of insulation failure, with maintaining such insulation a similar issue.  Rather than failing to protect the pipe due to cheaper materials, inappropriate material selection,  or inadequate thickness, the failure to protect the pipe occurs at the last stage of the project – installation.  Poor insulation installation is generally obvious to even the untrained eye, and for that reason should be caught and corrected rather than left to remain.  Yet the problem is not uncommon. The worst examples of poor workmanship can always be found at chill water and dual temperature systems installed behind walls and ceilings.  There, missing insulation, thin insulation, open seams, and even loose fiberglass tied around the pipe with twine have been documented.  …

Photo Gallery D5:  Mold Contamination The dreaded “M” word, and a massive legal and operational health threat to all real estate properties. Mold contamination on pipe insulation is found where wet conditions have existed over an extended period of time.  Commonly installed fiberglass insulation provides an excellent substrate for mold growth, as also does its cellulose paper covering.  Dramatically worse cases can be found at piping located behind walls or in enclosed areas having high humidity and darkness.  Cold water systems are at the highest risk to this condition due to moisture condensation; the inherent difficulty of insulating small threaded chill water fittings such as drains and vents easily allowing moisture to enter.  Furthermore, given the greater vulnerability of small pipe to leak at the threads, older threaded fittings can continuously release a small volume of water over an extended length of time. Sanitary waste systems, given that they are not pressurized and are typically installed behind walls, can leak for many years before being detected.  Although not insulated, the released moisture, along with its biological content, can result in widespread mold growth which can then travel within the building’s walls and floors with  its air migration.  Leaking condensate lines…

Photo Gallery D3:  Wet Dripping Pipe This problem is generally related to moisture migration and condensation at chill water and dual temperature piping systems, rather than at pipe exposed to an outdoor environment.  While wet and discolored insulation provides a clear indication to a potential CUI condition, pipe dripping water means far worse.  Even when not related to a failure, water droplets indicate that the insulation is saturated – providing no thermal benefit while exposing the pipe exterior to an untreated water environment.  Possible at any form of insulation and whether covered or not, water droplets define an extended period of time for CUI to have occurred. The consequences of such a condition are unpredictable.  Older pipe, due to its superior quality and corrosion resistance will generally outlast similar conditions at newer pipe.  A pinhole leak at a larger main represents a larger repair cost although a lesser threat of bursting, whereas, the same level of corrosion attack against a threaded connection always presents the opportunity for a total pipe separation failure.  Copper and brass pipe are generally unaffected by such insulation failure in terms of exterior corrosion. Since any form of wet dripping pipe can be detrimental to building…

Photo Gallery D4:  Soft Foam Insulation Soft foam insulation is preferred by contractors due to easier installation, its clean finished appearance, and less irritation compared to traditional fiberglass insulation.  It is growing in popularity to for many residential and smaller commercial properties where its smaller diameter piping systems are more easily covered by foam.  Soft foam is substantially better as a covering for smallest diameter pipe fittings such as vent lines and drains. However, soft foam insulation has significant drawbacks not immediately apparent, not well known, and certainly not advertised.  In many cases, it will result in far greater damage to cold water carrying pipe in comparison to fiberglass insulation, as this photo gallery demonstrates. While the thickness and appearance of soft foam insulation would suggest superior resistance to moisture migration, moisture often quickly penetrates through it to the cold pipe surface.  More importantly, soft foam insulation naturally degrades over time; a problem accelerated by the higher temperatures of any hot water system.  Sealants at the seams offer varying levels of effectiveness but ultimately weaken with age to produce extended separations of its edges.  As the material itself degrades, it becomes harder, less flexible, and more brittle, which then leads…

Photo Gallery D7:  Wet Insulation Wet, discolored, stained, or water marked insulation is the first sign of “insulation failure” and potentially an external pipe corrosion condition.  This is caused by inadequate, improperly installed, poorly maintained, or inappropriate insulation having allowed moisture to penetrate to the cold pipe surface.  Although touted as a “moisture barrier” by manufacturers and others in the trade, the paper foil backing common to fiberglass products is actually quite poor, and will inevitably allow moisture to pass through.  Once moisture reaches the pipe it condenses into water and then travels its most favored path to impact a much larger volume of pipe.  Water droplets on the floor unquestionably define that the insulation has failed, is saturated, and that it can hold no more water.  Although termed “insulation failure,” the issue is actually due to improper insulation methods themselves. Various factors influence this condition – the most significant being insulation thickness, pipe temperature, and area moisture content.  Properties in coastal areas such as Miami, Houston, New Orleans, and Puerto Rico are especially prone to this problem.  Supply side pipe at typically a 10° F. lower temperature, will exhibit the worst impact since it attracts and condenses more moisture. …

Photo Gallery D1:  Corrosion Under Insulation (CUI) As we have well documented in endless investigations, the failure to protect steel pipe from sweating and corroding at its outside surface produces some of the most widespread as well as expensive forms of pipe failure.  The extensive branch like layout of any chill water or dual temperature piping system behind finished walls means not only millions of dollars to replace, but also massive disruption to building owners and tenants.  When they fail, typically at the smaller diameter threaded risers and take-off lines, water damage alone can easily reach 4 to 8 floors below and the multi-million dollar mark. In the majority of cases, the first failure leading to its discovery reveals that the pipe has been almost totally destroyed, and that no corrective measures are available other than full pipe replacement.  Neither internal coatings nor external coatings will provide any benefit since almost no pipe wall remains in areas, and simply re-insulating the pipe without first stopping the corrosive attack is utterly worthless. Rehabilitating the pipe by removing all insulation, removing the rust product, coating the pipe with a “rust reverter” followed by a water proof paint overcoat, and then re-insulating to…

Photo Gallery D2:  Missing Insulation Missing or damaged insulation often occurs over time, and may be due to foot traffic, incomplete repairs, repeated impacts, emergency events, and other maintenance related activities   For waste and vent system where it is installed to reduce sound, no real impact exists.  For domestic hot water or other hot water heating systems, missing insulation only represents an energy loss.  For high pressure steam and high temperature hot water systems, it raises a greater threat in case of accidental contact. The most prominent threat, however, is at chill water and dual temperature systems, as our many Photo Galleries document.  Although missing insulation usually prompts its own repair after dripping condensation becomes a problem, that may not always be the case.  Given the inherent difficulty in insulating smaller diameter pipe, as well as pumps, strainers, and other odd shaped piping components, insulation is far more likely to be either missing or inadequate.  Strapped or tied together insulation jackets, while providing some aesthetic benefit, offer no protection whatsoever to any cold pipe surface, as moisture passes right through. Similar to all other forms of corrosion, the impact of missing insulation and its resulting external corrosion is greatest…

Photo Gallery Series C:  Pipe Quality Many piping failures are easily predicted by the source of the materials used, pipe schedule, piping design, age, building supplied maintenance, and many other facts.  Almost every aspect of piping design and construction has navigated toward lower quality and cheaper materials, assembly methods requiring no skill, and above all – cost reduction.  The use of ERW seamed pipe would have never been allowed 40 years ago, yet today has become the standard for HVAC and fire protection service. Our investigations has documented most new pipe manufactured undersized its ASTM specification and the wall thickness stamped on its side, as permitted.  Even the threading of thinwall schedule 10 and thinner pipe is now permitted for some piping systems.  Add in “value engineering” during the pre-construction process and accelerated system failures become relatively simple to explain. This series of Photo Galleries relates to the many factors significantly limiting a piping system’s service lifespan from the very start.