In the mid-1950s, Kunkle purchased railroad valve manufacturer J.E. Lonergan, strengthening the new corporation's standing as a respected manufacturer of safety and relief valves. In November 1991, Kunkle Industries became a publicly held company following its purchase by Anderson Greenwood & Co. The pairing of the Kunkle and Lonergan spring-activated valves with the pilot-operated valves manufactured by Anderson Greenwood, resulted in a stronger market position for Kunkle in the relief valve industry.

In September 1997, Kunkle Valve, as a part of Anderson Greenwood and Keystone, became a part of Tyco International Ltd. In addition to the above companies, Tyco's Flow Control group includes many well established companies such as Grinnell, Mueller, Unistrut, Vanessa and Yarway.