PIR400 is a rigid, closed cell polyisocyanurate insulation designed to operate at a continuous temperature of 400°F, with intermittent service up to 450°F. With industry leading thermal conductivity, PIR400 is an ideal product for use on 150 lbs. steam lines (366°F). Mechanical systems looking for excellent thermal performance as well as low water absorption and vapor permeability would benefit greatly from PIR400.