Plumbing Engineer October 2021/60
815-886-9200 metropolitanind.com 518-694-0404 emmonspump.com LED indicates the associated output status More precise temperature control than traditional thermostatic mixing valves Automatically lower target temperature during low usage periods Able to manually throttle without loss of digital benefits Digital display shows sensor temperatures, set point, valve modulations Connects to building automation for data logging Immediate alarm notifications
THE MASTERMIND BEHIND YOUR DOMESTIC HOT WATER SYSTEM
MetroMix Hot Water Electronic Mixing Valve
The aboveground pipe was insulated with fiberglass (not a good idea). It took a few years, but the fiberglass insula- tion filled with condensation and started dripping every- where. The underground pipe was part of an inexpensive conduit system, which failed due to a high groundwater table. The new owner of the complex is reinsulating the aboveground pipe with 3-inch-thick cellular glass. The underground pipe is being redone with a better-quality conduit system consisting of many maintenance holes for valves and expansion joints. It is a multimillion-dollar project. Another classic problem is the noninsulation of valves. The design engineers should specify valve stems with a thermal block or similar as sold by Jomar. O William A. Lotz, consulting engineer in St. Albans, Vt., has a degree in mechanical engineering and is a licensed P.E. in eight states. His work career includes several years with insulation manufacturers, many years with insulation contractors - plus many more years as a consulting engi- neer designing and troubleshooting pipe insulation prob- lems. Lotz has more than 300 articles in the trade press and recently published his first book, "Moisture Control and Insulation Systems in Buildings, Chilled Water Pipes and Underground Pipes." adhesive. The thermal value of the 1/2-inch insulation was barely adequate, but the thermal value of the adhesive in the insulation joints was not. I recommended the re-insulation be done with Aeroflex Aerocel ULP pipe insulation at 1-inch thick. Large Multibuilding Office Complex, Mid-Texas The chilled water system consisted of miles of pipe up to 24 inches in diameter, with some of the pipe underground.
Failed insulation at valves: Cold valves (and outdoors) should have had insulation with a weather seal and vapor seal on the entire valve body. Photo: William Lotz, P.E.
Chilled Water Pipes
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