Published on August 4, 2014
Glass Lining Submittal U.S. Pipe Fabrication Vitco®, SG-14® Glass Lining Submittal Revision 1 U.S. Pipe Fabrication Vitco ®, SG-14® 2 of 4 Revised 8/01/14 III. Lining Material The glass lining applied to pipe and fittings shall be hard, smooth, continuous vitreous material which is formulated to prevent the adherence of grease in sludge and scum lines, and to resist the adherence of crystalline metal salt deposits (Struvite and Vivionite) to sludge and centrate lines in sewage and wastewater treatment plants. The glass portion of the lining, the frit(s) used in the formulation, as supplied from the manufacturer, shall have a density of 2.5 to 3.0 grams per cubic centimeter as measured by ASTM D-792. IV. Lining Process The slip (mixed slurry) shall be prepared according to documented procedures. Pertinent quality control characteristics including specific gravity (SG) and Pick-up shall be recorded. The slip shall be applied to the freshly blasted substrate within 8 hours of blasting. The slip shall be applied to a minimum wet film thickness (WFT) to provide the desired dry film thickness (DFT). The freshly applied slip shall be thoroughly dried. The coated product shall be fired according to documented procedures. Times and temperatures should reflect those needed to provide the physical and corrosion results desired. Pertinent quality control characteristics including oven temperature and time at temperature should be recorded. The fired lining shall be inspected. V. Lining Characteristics The lining shall be of a light, bright color to allow visual detection of defects more easily prior to electronic holiday detection testing. Glass linings are not intended to be Holiday free, but to prevent the build-up of grease, scum, and crystalline metal salt deposits. The entire finished coating shall be a minimum of 10 mils (0.010 inch) as tested with an acceptable Type I or Type II dry film thickness gage as described in ASTM D7091. The finished lining shall be able to withstand a strain of 0.001 inch/inch of the base metal without visible damage to the glass. The glass lining shall have a minimum hardness of 5 on the Moh’s hardness scale. The lining shall be capable of withstanding an instantaneous thermal shock from ambient 350 o F to ambient without visible crazing, blistering or spalling.