Inflatable Pipe Plugs (Click for more Info) Type "C" Inflatable pipe plugs are fabricated from the finest quality Natural rubber and are totally vulcanized. No adhesives or cements are ever used. Bladders are then encased in a 100% polyester cloth cover. All cover seams are TRIPLE sewn. The thickness of the rubber and polyester cloth vary according to the size of each plug. Every plug is expertly manufactured to ensure a snug fit thus assuring a secure shut-off of the pipe when inflated. All inflating valves and fittings are BRASS and STAINLESS STEEL and are standard with each Type "C" plug. No parts can rust. 0-15 lb. air pressure gauges are required so that plugs are not over-inflated. Gauges can also be furnished upon request.