... .Closed-cell flexible 4.Fire proof, MoistureproofBellsafe-flex adopting NBR/PVC as the main raw material, is an environmental product.It ... of central air conditioning system,and its chilled water pipes,condensate pipes, air ducts, and hot-water pipes of air-condition equipment. Meanwhile ,it is ... foam, fireproof apply in HVAC system Specification: Main material : NBR/PVC ID size:1/4", 3/8", 1/2", 5/8 ...