A rotary valve position indicator is disclosed. An example apparatus includes an actuator housing defining an explosion-proof enclosure boundary. An actuator output shaft has a first shaft portion and a second shaft portion. The first shaft portion is partially disposed within the explosion-proof enclosure boundary, and the second shaft portion is disposed outside of the explosion-proof enclosure boundary. A visual position indicator is disposed on the second shaft portion of the actuator output shaft and indicates the rotational position of the actuator output shaft relative to the actuator housing.

A memory stop includes: a cover plate; a memory bracket secured to the cover plate, the memory bracket defining a plurality of stopper positions; and a stopper attached to the memory bracket at a one of the plurality of stopper positions. A method of using a memory stop includes: moving a stopper of the memory stop to a memory position, the memory stop including a cover plate, a memory bracket secured to the cover plate and defining a plurality of stopper positions, and the stopper attached to the memory bracket; and securing the stopper to the memory bracket at the memory position, wherein the memory position is at one of the plurality of stopper positions.

An actuator apparatus includes and actuator and a yoke. The actuator includes an upper casing and a lower casing defining a cavity and an actuating device disposed at least partially within the cavity and dividing the cavity into an upper chamber and a lower chamber. The yoke is connected to the actuator and has an actuator spring disposed within a body of the yoke and a yoke tube extending longitudinally through the body of the yoke. The yoke tube extends from an aperture in the lower casing of the actuator and provides an air passage that fluidly connects the lower chamber of the actuator and a controller.

A method and apparatus for self-calibrating control of gas flow. The gas flow rate is initially set by controlling, to a high degree of precision, the amount of opening of a flow restriction, where the design of the apparatus containing the flow restriction lends itself to achieving high precision. The gas flow rate is then measured by a pressure rate-of-drop upstream of the flow restriction, and the amount of flow restriction opening is adjusted, if need be, to obtain exactly the desired flow.

A combined balancing and control valve suitable for use in a hydronic system is provided, including a chamber enclosing a plug (6, 10, 16, 15), a seat (13) and a cam and pinion mechanism (20-28) for adjusting the separation of the plug (6, 10, 16, 15) and the seat (13). Pressure ports (42, 43) are included for monitoring the rate of fluid flow across the separation. The cam and pinion mechanism provides a motion transformation (20-27) operable by an actuator (28) to control the motion of the valve plug (6, 10, 16, 15). The valve plug motion provides a favorable change in conductance of the valve for a given change in the actuator position. The actuator (28) is calibrated in increments which correspond to incremental changes in the conductance.

A structure of gas regulator comprises a space for setting an intake switchover valve formed at an outer end of a high-pressure portion and interconnected with the inside of the high-pressure portion. A pushing block is outside a diaphragm, and an elastic element is set between the pushing block and a flange at the periphery of an inner end of the pushing block. A support base outside the pushing block is abutted the elastic element and comprises an extending section extended from an inner end thereof and corresponding to the outer periphery of the elastic element and a through-hole corresponding to the pushing block. A display diaphragm with a center slot is outside the support base. A cover covered the space has a transparent side display window at the periphery thereof and a transparent outer display window at an outer end thereof.

An integrated multi-way valve includes: a mounting panel, N channel interfaces being defined on the mounting panel; a valve seat fixedly connected to the mounting panel, N openings being defined on the cylindrical valve seat and in communication with N channel interfaces correspondingly; a valve cartridge disposed in the valve seat in a close engagement manner with the valve seat, a plurality of communication grooves being defined on a circumferential surface of the valve cartridge; and a driving assembly in transmission connection with the valve cartridge and configured to drive the valve cartridge to rotate by a predetermined angle to bring at least one target communication groove of the plurality of communication grooves into communication with a plurality of target openings of the N openings. Each of the at least one target communication groove is in communication with at least two of the plurality of target openings.