Mitsui Chemicals Inc.’s new production plant has been equipped with Rotork IQPro intelligent electric actuators that are specially designed to assure the reliable performance of valves subjected to operation in high and dramatically fluctuating temperatures. The new plant, which is being installed by Mitsui at Ichihara, Japan, uses Mitsui’s proprietary technologies to manufacture specialised chemical products. During the process the gate valves operated by the Rotork actuators will be handling gases at temperatures between 300C and 650C. In such severe operating environments there is a potential danger that a closed valve could become jammed in its seat as a result of the thermal expansion of its valve stem. In extreme cases this can cause the valve stem to distort or the valve to break. The design, known as the thrust compensator, was originally developed to overcome critical high temperature applications in the nuclear power generation industry. The thrust compensator consists of a spring-loaded stem nut that will absorb any expansion or contraction caused by temperature fluctuations without affecting the position of the closed valve stem. The construction of the device is also designed to ensure that the positive valve shut-off demanded in critical applications is not compromised.
