Abstract: A chemically-resistant fluid control valve is disclosed generally comprising fluid inlet and outlet passages separated by fluid control means, which control means comprise a flapper plate disposed in the fluid passageway and mounted on a rotatable shaft that passes laterally through the fluid passageway by means of releasable fasteners adapted to engage correspondingly-shaped fastener elements of the flapper plate, which elements are also adapted to receive the shaft in a channel between the fastener elements, wherein at least all wetted surfaces of each of the several components consist essentially of a chemically-resistant material.

Abstract: A heated fluid control valve with an electric heating element and a thermocouple disposed in a rotatable support shaft comprises a metallic flapper plate disposed in a fluid passageway and mounted on, and in thermal contact with, an elongated, rotatable metallic shaft that passes laterally through the fluid passageway. The shaft is heated by the internal heating element and, in turn, heats the flapper plate along the entire length of the shaft.