Abstract: A valve operator having a piston or diaphragm and connected polygonal piston rod which supplies reciprocable motion to a key or follower which acts within a spiraled slot formed in a coupling member attached to a valve gate to rotate the valve gate to a desired angular position. One embodiment includes means to bias the piston and the valve gate in a desired angular position from closed to open or therebetween.

Abstract: A safety valve having an upright tubular body with an axial opening therethrough, a portion of the opening at the lower end forming a flow passageway, the body having outlet ports extending from the flow passageway to the external cylindrical surface, an end cap closing the upper end of the axial opening, an internal stem guide within the axial opening separating the lower flow passageway from an upper cylinder and having a reduced diameter axial opening, a plunger reciprocally positioned within the flow passageway, the plunger having an upwardly extending axial stem received in the stem guide and the plunger having a seaing surface on the lower end, a seating surface within the flow passageway between the inlet ports and the open lower end of the passageway, the seating surface being engaged by the plunger sealing surface when the plunger is in the downward, valve closed, position, a piston positioned in the upper cylinder, the piston being affixed to the upper end of the plunger stem, the body having a smal