GB879548A - Improvements relating to pressure gauges for wells - Google Patents

Abstract

879,548. Pressure gauges. HUGEL, H. June 26, 1958 [June 26, 1957], No. 20591/58. Class 106 (2). A fluid pressure gauge for lowering into oil wells comprises an air or gas filled chamber 23 in which a stylus 9 mounted on a shaft 7 records the axial and angular displacements of the shaft 7 or a cylindrical sheet 10, a second liquid-filled chamber 19 into which the shaft 7 extends through a seal 28, 29 and in which a spring 6 is situated to couple the shaft 7, through a spindle 5, to a motor 3 which rotates the shaft 7 at a constant speed, and a flexible wall or diaphragm 16 to transmit the pressure of the well liquid to the liquid in the chamber 19 to act on the shaft end against the biasing force exerted by the spring, safety valves being provided to effect pressure equalization between the chamber 19 and the oil well. The well liquid enters the gauge through an aperture 12 when it is lowered ,into the well. The lower safety valve consists of a hole 24 below an annular bead 241 which normally stretches and seals the diaphragm except when there is an excess pressure of well liquid. The upper safety valve consists of an axially movable carrier ring 15 which normally seals the diaphragm against the outer wall of the chamber 19 but brings this chamber into communication with a chamber 26 when the diaphragm expands longitudinally due to excess pressure in the chamber 19. The spindle 5 is secured against axial displacement. A compression spring may be used instead of the tension spring 6. A filter-like tube 20 with a connecting bore 21 is provided for washing out impurities. which have entered through the aperture 12. A maximum thermometer may be provided a chamber 11, Fig. 3.