The disclosed technology is a pressure transducer with a bleed valve built into the body of the transducer for purging liquid systems. The transducer assembly includes a body, a bleed valve port defined in the body and configured to accept a bleed valve, an interface port attached to the body, an adapter attached to a portion of the interface port, a header attached to the adapter and the body, a pressure transducer mounted to the header, and an internal cavity in communication with the interface port, the pressure transducer, and the bleed valve port. The bleed valve port is configured to vent a gas from the internal cavity. A bleed valve disposed in the bleed valve port is configured to controllably vent a gas from the internal cavity.

A leakage of liquid inside a differential pressure detection device is reliably preventable. A diaphragm portion that detects a differential pressure as a pressure difference between a high pressure side and a low pressure side includes an annular member, a strain gauge provided in a hollow portion of the annular member, and a first plate and a second plate provided such that the annular member and the strain gauge are sandwiched. The first plate and the second plate each abut on a first annular packing. A first groove and a second groove (the first annular packing) overlap with the annular member when viewed from a first direction along an axis of the first hole.

A pressure sensor includes a cylindrical member configured to be attached to a body having a fluid passage, and a pressure sensor unit connected to the cylindrical member for detecting a pressure of a fluid flowing through the fluid passage, wherein the cylindrical member is made of a nickel-molybdenum-chromium alloy material or a stainless steel material, wherein the pressure sensor unit includes a sensor body closed at one end with a diaphragm and a pressure detecting element for outputting displacement of the diaphragm as pressure, and wherein the sensor body is made of a cobalt-nickel alloy material, and is connected at an opening side end portion to one end portion of the cylindrical member.

Embodiments of a pressure switch assembly having a quick connect capillary tube are disclosed. One embodiment, among others, has an elongated cylindrical capillary tube for attachment to a refrigeration line so that refrigeration fluid pressure in the refrigeration line can be sensed. A quick connect coupling is connected to the shutoff valve. A shutoff valve is designed to open and close fluid communication between the capillary tube and the quick connect coupling when the quick connect coupling is coupled and decoupled, respectively. A switch body is connected to the quick connect coupling and has first and second electrical connections. The switch body has an internal on/off switch designed to electrically connect and electrically disconnect the first and second electrical connections based upon a predetermined set point of pressure associated with refrigeration fluid that is in communication with the switch body.

An overpressure indicator is defined by a housing sized and configured for attachment within a compartment interior, such as an aircraft nacelle. A pressure sensing element disposed within the housing is coupled to an indicator element and is configured to detect a pressure differential between the interior and exterior of the compartment. The indicator element is caused to move in response to a predetermined change in pressure exceeding a threshold pressure differential. The indicator element includes a distal end that is moved to a position exterior of the housing and the compartment, providing a visual indication of an overpressure condition. A reset feature provided on the indicator can only be accessed by first opening the compartment in which the indicator has been mounted. A spring can be provided to assist in the triggering of the indicator member after the threshold pressure differential has been detected.

Embodiments of a pressure switch assembly having a quick connect capillary tube are disclosed. One embodiment, among others, has an elongated cylindrical capillary tube for attachment to a refrigeration line so that refrigeration fluid pressure in the refrigeration line can be sensed. A quick connect coupling is connected to the shutoff valve. A shutoff valve is designed to open and close fluid communication between the capillary tube and the quick connect coupling when the quick connect coupling is coupled and decoupled, respectively. A switch body is connected to the quick connect coupling and has first and second electrical connections. The switch body has an internal on/off switch designed to electrically connect and electrically disconnect the first and second electrical connections based upon a predetermined set point of pressure associated with refrigeration fluid that is in communication with the switch body.

A pressure measuring unit includes a pressure measuring cell; a rotationally symmetrical sensor bushing into which the pressure measuring cell is inserted; a rotationally symmetrical process connection having, at one end, an inwardly extending encircling stop surface intended for the sensor bushing and, at another end, an opening for receiving the sensor bushing; a ring-like process seal between the sensor bushing and the stop surface of the process connection in order to thus prevent an ingress of the process medium into the pressure measuring unit; wherein the stop surface of the process connection and/or a counterpart stop surface, which in the installed state is directed toward the stop surface, of the sensor bushing have multiple individually formed webs configured such that the process seal is not extruded into the openings.

A pressure measuring device is disclosed that includes a housing, a pressure measuring cell, evaluation electronics for processing measurement signals generated by the pressure measuring cell, a plug connection formed at the housing for transmitting the processed measurement signals to an external receiving unit, and an air passage which enables pressure compensation between the interior of the housing and the exterior of the housing. The plug connection includes a cylindrical sleeve and an insert part disposed therein, wherein the air passage is formed as a two-part barrier having a first liquid barrier formed as a duct system from the interior of the housing via the plug connection and a second liquid barrier having a liquid-repellent diaphragm and disposed in an area within the duct system, and wherein the insert part has a first recess into which the diaphragm is inserted. The insert part has a second recess, which is arranged at a distance from the first recess and in which a light-emitting diode signalling a status of the measuring device is inserted, wherein the cylindrical sleeve also has a recess at the side opposite the light-emitting diode, which recess on the one hand, acting as a part of the duct system or air passage, allows pressure compensation and, on the other hand, allows the light-emitting diode to be visible.

A sealing pin includes a body part and an end part connected to the body part. The body part is insertable into a liquid filling path of a pressure sensor. The body part has a groove on an outer surface. The end part seals a liquid filling port of the liquid filling path. When the sealing pin is inserted into the liquid filling path, an external media pressure applied to a diaphragm of the pressure sensor is transmitted to a pressure detection chip of the pressure sensor through a liquid in the groove.

A leakage of liquid inside a differential pressure detection device is reliably preventable. A diaphragm portion that detects a differential pressure as a pressure difference between a high pressure side and a low pressure side includes an annular member, a strain gauge provided in a hollow portion of the annular member, and a first plate and a second plate provided such that the annular member and the strain gauge are sandwiched. The first plate and the second plate each abut on a first annular packing. A first groove and a second groove (the first annular packing) overlap with the annular member when viewed from a first direction along an axis of the first hole.