Inquiry (采购产品): Dielectric Fittings - NYS Office of General Services - Design & Construction Hi, My name is James Bishop. I'm with New York State Office of General Services, Design & Construction, Heating Ventilation and Air Conditioning. The Design and Construction group is responsible for over $500,000,000 of construction work per year. I have a few questions regarding dielectric nipples and dielectric flanges. To give you some background information on our problem; dielectric unions were specified, submitted, approved and installed on glycol heating lines. After ceilings were installed and the heating system had begun operating, union connections began to leak, due to heat pipe expansion and contraction, causing staining of ceiling tiles and walls. On a few occasions, repairs were attempted by tightening the union however the piping was hot so the union gasket compressed and failed. The unions were then replaced however we anticipate repeated failure. These expenses are paid by OGS or by the building owner. It was later recommended that we change our master specifications to use dielectric nipples instead of unions because they can handle the temperature fluctuation. However a corrosion engineer claims that the glycol will degrade the thermoplastic lining of the nipple and/or gasket of a dielectric flange over time causing corrosion and ultimately leaking. The use of brass nipples was proposed as an alternative solution but our corrosion engineers were unfamiliar with the affects of glycol on the brass. Our heating systems use a combination of water and environmentally friendly propylene glycol with a concentration never exceeding 40%. We need to determine what kind of fitting or brass fitting assembly to use in order to eliminate this problem. Then the master specifications will be updated to specify a manufacturer and product number for these types of applications. Thank you very much for your assistance If you have any questions or need me to make any further clarifications please feel free to contact me. **** Hidden Message ***** James Bishop Empire State Plaza, Corning Tower 31st Floor Albany, NY 12242 USA Company: New York State - Office of General Services – Design & Construction Title: Mechanical Engr Phone: 518-402-5813 E-mail: james.bishop@ogs.state.ny.us **** Hidden Message ***** james.bishop@ogs.state.ny.us
