FILAMENT-WOUND FIBERGLASS REINFORCED PLASTIC DUCT-WORK AND TUBING FOR HEATING, VENTILATING AND AIR CONDITIONING SYSTEMS, AND EXHAUSTING OF CONDITIONED OR CORROSIVE GASES, AND PARTS AND FITTINGS THEREFOR; [ AND ELECTRIC FANS FOR INDUSTRIAL AND MINING USE ]

FIBERGLASS-REINFORCED PLASTIC DUCT FOR HEATING, LIGHTING, AND VENTILATING SYSTEMS