A national mining and metals manufacturer of cobalt and tungsten used gate valves and orifice gates as airlocks in feeding applications, as well as discharge valves on its vacuum receivers and blenders. However, the gates were notorious for leaking, resulting in high air usage and a very dusty working environment. In addition, the valves had a tendency to bind up due to product buildup during the discharge process. Repairs were frequent and costly in maintenance downtime.

The Solution

The feeding applications, which total over 1.2 million cycles each year, required the valves to cycle 200-300 times each hour. A major concern with this high cycle rate was the amount of wear on the seat caused by the very abrasive cobalt oxide powders.

A decision was made to purchase 10 Posi-flate inflatable seated butterfly valves to replace the orifice gates, which were acting as airlocks. When this installation proved successful, three more Posi-flate valves were installed as discharge valves on the bottom of the vacuum receivers and a blender.

The Results

The Posi-flate valves have eliminated dust leaks and product leaks past the valve seat. Air usage has been minimal and, due to the dynamics of the Posi-flate valve, product buildup is no longer a problem.

The maintenance crew is especially pleased because, with the exception of replacing a seat during scheduled maintenance, inspections and downtime have been reduced considerably. Mine personnel report that the Posi-flate valve is ideally suited for their very abrasive application.