The stationary portion of the BAF consists of a specially designed cast iron base elbow which is bolted to the floor of the wet well. The pump bolts to the cast iron moveable portion which is free to ride up and down the guide rails. An O-Ring is pressed into a dove-tailed groove on the tapered face of the moveable elbow. The tapered faces of the moveable and base elbow allow for a positive mating of the O-Ring to base. This elastomer to cast iron contact assures a complete and positive seal which allows pumps to operate without hydraulic leakage, over a wide range of discharge pressures.
The guide rails are attached to the base elbow at one end and to a stainless steel guide cap, which is attached to the underside of the wet well cover, at the other end. Both the guide cap assembly and the base elbow have cast iron plugs with O-Rings mounted in them which aid in locating the guide rails and in reducing noise and vibration of the guide rail.
The guide rails serve only to guide, they carry none of the pump weight. 1 1/2” schedule 40 pipe should be used for guide rails. An intermediate guide pipe bracket should be used for depths of 13 feet or more.
