Abstract: A first belleville spring, having a given preload, controls a translatable, elongate, contact disc assembly, to cause a shunting disc to remove from, and close into contact with a pair of circuit contacts. The assembly is disposed within a translatable carriage, and a second belleville spring having a greater preload controls translation of the carriage, to cause the shunting disc to close into contact with, and remove from, a second pair of circuit contacts. As a consequence dual set points of switching operation is provided. A fluid medium, admitted into a housing for the assembly and carriage, effects translation of the assembly and carriage.

Abstract: A high pressure piston seal with low pressure seal capabilities. At high pressure the seal configuration increases the footprint loading for high pressure sealing. The seal arrangement also provides a labyrinth effect at low pressure combined with reduced loading.

Abstract: A wire wand is inserted into a pressure sensor perpendicular to the sensor's operating axis. The wire wand is fixed and adjustable at one end and driven at the other end by the sensor. The arrangement provides for deadband adjustment of a pressure switch.

Abstract: A fire isolation device having a valve designed to close after a given temperature has been reached by a fusible nose member in the form of a sleeve of fusible material. The device has a passageway therethrough and a self-closing valve member having a poppet and a seat disposed in the passageway with the poppet being biased toward the seat to a valve closed position. At least one aperture through the nose member provides for continuous fluid flow through the device around the poppet and the seat. The nose member is positioned to hold the valve in an open position against the bias on the poppet. The seat has a flow path on its outer end dimensioned to fit the nose member and a flow path towards its inner end larger in diameter than the nose member in an area occupied by the aperture to permit flow therethrough when the nose member holds the valve in an open position. The nose member is made of a material designed to melt in the neighborhood of 700.degree. F. when the fire isolation device is exposed to 2000.

Abstract: A pressure fitting formed of fire resistant material, preferably stainless steel, contains a chamber communicating through an opening with a pressure responsive switch or other assembly formed at least in part of a less fire resistant material, such as aluminum, with a movable seal member being provided for transmitting force to a movable part of the assembly, and with a valve member which is also high temperature resistant being provided to automatically close off fluid flow from the chamber through the opening in the event of fire. The temperature response may be obtained by release of the valve resulting from melting down of part of the pressure responsive assembly, or by melting of a fusible element retaining the valve in open condition, or by both of these effects.