Abstract: An air bleeding pipe joint has a pair of connection pipe portions, a branch pipe portion having an air bleeding hole in an inside thereof, a plug body, and an elastic annular sealing member providing an air-tight seal between a female fitting surface of the branch pipe portion and a male fitting surface of the plug body. The plug body is removably mounted to the branch pipe portion in threaded engagement therewith such that a seating surface of the plug body seats on a seated surface of the branch pipe portion. An air discharge path is provided on an upper end of the branch pipe portion and/or the plug body with respect to a sealing position at which the sealing member is disposed for discharging outwardly an air that leaks upwardly through the sealing position.

Abstract: A pressure sensor comprising a flexible substrate, and a piezoelectric element for detecting a pressure,. The piezoelectric element includes a piezoelectric layer and an electrode layer which are formed on at least one of the opposite sides of the flexible substrate such that the piezoelectric layer is disposed between the flexible substrate and the electrode layer. The pressure sensor is characterized by the formation of the piezoelectric layer by hydrothermal synthesis or hydrothermal crystallization method.