Abstract: The specification discloses a system for mounting a communications antenna and a solar panel on an explosion-proof housing that does not require the use of conduit ports of the explosion-proof housing. More particularly, a mast couples to the housing by way of a prescribed number of threads, the mast having a circular cross-section and an internal cavity extending along its axis. Wires extending from inside the explosion-proof housing through the mast couple to the radio antenna and the solar panel. The void within the internal diameter of the mast not occupied by the wires for the radio and solar panel is filled with a sealing compound rated for explosive environments.

Abstract: The specification discloses a system for mounting a communications antenna and a solar panel on an explosion-proof housing that does not require the use of conduit ports of the explosion-proof housing. More particularly, a mast couples to the housing by way of a prescribed number of threads, the mast having a circular cross-section and an internal cavity extending along its axis. Wires extending from inside the explosion-proof housing through the mast couple to the radio antenna and the solar panel. The void within the internal diameter of the mast not occupied by the wires for the radio and solar panel is filled with a sealing compound rated for explosive environments.

Abstract: A controller of the type used in process control includes a plurality of modular I/O units. The I/O units includes I/O circuits which may be of four basic types: digital input circuits, digital output circuit, analog input circuits and analog output circuits. Each of the I/O circuits has a code generator that generates a binary code indicating the type of I/O circuit. The controller is microprocessor-controlled and periodically communicates with the I/O circuits and determines the type of each I/O unit based upon the binary code. The I/O units may be temperature-compensated based upon the temperature within the housing of the controller, and other integrity checks may be performed on the I/O units. The controller also has a change module routine which allows the I/O units to be installed or removed during operation of the controller.

Abstract: A pressure relief diaphragm type regulator valve includes a velocity boost body having an annular-shaped wrap-around pitot tube communicating with the vena contracta of a flowpath. The pressure at the vena contracta is communicated to the diaphragm by a small registration orifice in the boost body. The boost body defines a large relief orifice open to the annular pitot tube, but normally closed off from the diaphragm by a flapper. Under a rapid excess pressure condition, the flapper uncovers the relief orifice and large volume flow is permitted to the diaphragm.

Abstract: A rolling diaphragm regulator valve is affixed in a globe type valve body and includes a non-stretchable fabric reinforced liner for covering and uncovering, by rolling action in response to changes in pressure in a control chamber, a plurality of slots in a baffle positioned between the valve body inlet and outlet. An axially movable spring-biased nose cone, mounted behind the diaphragm, provides a surface over which the diaphragm is draped for controlling substantially all movement of the diaphragm. A travel indicator is operable by movement of the nose cone to provide a visual indication of the position of the valve.