Armaflex over Schedule 40 black chill water pipe caused corrosion of exterior.

 Rarig Center AHU # 3 Chill water lines - Schedule 40 pipe.  Pipe OK under fiberglass.  Pipe rusting out with Armaflex covering the schedule 40 pipe. Thanks to Karen Haakonson for the pictures. Armaflex works on copper pipes and heating lines.

Rusty pipe under Armaflex insulation

Insulation 

Pipe snapped off

Rusty pipe under insulation