Bob Dewhirst, western regional manager with Everlasting Valve Co., explains the operation of the company’s bulk material valve. Everlasting Valve Company was founded in 1906 by Patterson Allen Engineering, New Jersey, to manufacture and market steam boiler blowdown valves. During the 1960s, the distinctive features of the Everlasting Rotating Disc Valve were incorporated into our process valves, bulk material valves and...