A passive fire protection Alternative for air distribution units, smoke control and kitchen area grease ducts Promat has made self-supporting devices and not using a steel liner, as an example PROMATECT®-Advert, PROMATECT®-L500 and MASTERBOARD®, which often can match the leakage and air stream functionality of steel ducts both of those https://fire-resisting-ductwork-i13455.blog2freedom.com/36983566/fire-resisting-ductwork-insulation-can-be-fun-for-anyone