System – Dual Temperature Likely The Greatest Threat To Any Building Property In Which It Exists Overview Dual temperature piping systems, as the name implies, are 2 pipe HVAC designs carrying hot water during winter or cooler months, and chilled water during the summer and warmer months.  They are a simple and an extremely common engineering design found in residential, apartment, condominium, hospital, high rise office building, and many other building designs.  Multiple set of risers commonly travel up and down the perimeter building columns where they run-out to serve window located fan coil units.  A third gravity drain line exists to carry away the condensate created during the summer air-conditioning season. The pipe runs either hot or cold as determined by building engineering or a building management program; its temperature determined by outdoor conditions.  With supply and return risers installed to every or every other perimeter column, the presence of 30 or more sets of risers over 40 floors separated into multiple vertical zones are not uncommon. Do the math, and the extraordinary damage due to failure…

Foreign Sources Beginning Service At A Disadvantage The issue of foreign produced pipe outside of the United States has transformed in significance and importance over the last few decades.  Beginning in the early 1980s foreign sources from China and Korea began showing up at construction sites due to its significantly lower cost.  That lower cost was quickly recognized as having a consequence given soon appearing experiences with noticeably low quality, difficulty in cutting and welding, ERW seems that would split during pressure testing, and much greater vulnerability to corrosion – all of which combined to provide significantly lower service life. For galvanized steel pipe, the zinc finish would flake off during rolling the groove or threading.  Of the many piping systems common to any building property, condenser water, chilled water, hot water heating systems, and domestic water were the most often impacted given their larger size favoring the greatest cost savings.  Older experienced steam fitters would object to its use, yet rarely succeed in having it replaced. The high incidence of problems associated with foreign produced pipe quickly resulted in some consulting engineering firms excluding foreign pipe…

Undersized Pipe A Simple Dial Caliper Measurement May Reveal Surprising Results Up until about 25 years ago, most new pipe was manufactured at its defined ASTM wall thickness.  Prior to that, and going back 30 years or more, pipe was typically manufactured above its specification sufficiently that even today, we can provide examples where an ultrasonic examination of older pipe pipe still exhibits a wall thickness higher than formally defined. Today, most pipe is produced substantially undersized due to what we believe are closer production tolerances enabling manufacturers to produce a lighter but still approved product within the tolerable limits of the ASTM code.  Extensive testing of new steel pipe has consistently found undersized material statistically beyond the possibility of being a random event.  With a permissible tolerance of 25% or + / – 12.5%, most new pipe we measure is toward the lower boundary of this limit, and very rarely at true ASTM factory specification or above.  An FM or UL stamped approval rating does not mean that the pipe wall is at true ASTM specifications, just the wall thickness dimension it should be.

Deteriorating Pipe Quality A Downward Spiral Of Lower Quality And Greater Corrosion Vulnerability Has Significantly Reduced The Service Life Of Most Piping Systems     In contrast to the high quality of pipe manufactured 50 years ago, we find few new properties unable to control corrosion at the condenser water system below 5 MPY today without expending extraordinary cost, supplemental filtration, close monitoring, and added physical effort. Chemical treatment programs costing $8,000 only 15 years ago now reach almost 8 times that expense.  Fully automatic chemical feed and bleed systems are no longer a convenience, but mandatory.  Yet, ultrasonic and metallurgical testing at newer installations typically reveal corrosion rates in the 3 – 5 MPY range, with some examples exceeding 15 to 20 MPY.  Such high corrosion rates are even found in examples where the chemical water treatment has been extremely well maintained. We have either directly seen or have been advised of condenser water or process piping systems which have been entirely replaced after only 10 years of service or less, and have found 6 year old large diameter 8 in. and 12 in. main…

Piping Changes – Past to Present Lower Quality, Thinner Schedules, Undersized Pipe, And Greater Corrosion Vulnerability Mean Far Less Service Life The below three photographs dramatically illustrate our continuing concerns and warnings to the industry over the deteriorating quality of not only steel pipe, but to all American piping products. One photo represents a 12 in. steel HVAC condenser water riser in operation for 27 years and chemically treated to control corrosion until a failure removed it from service.  The second from the inside of a 54 year old steel domestic water storage tank, coated to protect it from corrosion.  And the third from a steel side wall plate from the RMS Titanic, having rested on the bottom of the Atlantic ocean for over 108 years. Courtesy Lydia Frenzel and the Titanic Restoration             Indeed, without our photo credit and the rivets at the Titanic hull to give away the answer, how many readers might have guessed entirely wrong? While there are significant differences which make the above comparison somewhat invalid, most notably that the…