, Hart&Cooley. i MERCIA SERIES FLEX METABOLIZED VAPOR BARRIER FIBERGLASS INSULATION CORE FIBERGLASS SCRIM CORE Two tough plies consisting of a layer of metabolized polyester and a layer of clear polyester encapsulating a steel wire helix creating a high strength and durable product. Rated pressures (UL-181): 16 in. W.C. positive, 1 in. W.C. negative & 1/2” W.C. negative *Recommended maximum operating pressures (ADC Test FD 72—R1): 6 in. w.g. positive for 12 in. diameter and under. 4 in, w.g.
