GB811916A - A fluid pressure indicator - Google Patents

Abstract

811,916. Pressure indicators. BASTIANBLESSING CO. July 11, 1955, No. 21339/57. Divided out of 811,915. Class 106 (2). A fluid-pressure indicator comprises a body 20 connected to a pressure source by a passage 25, a resilient diaphragm 28, a bonnet 30 clamping the diaphragm in place and having a window 34 therein, a signal element 50 movable in response to movement of the diaphragm 28 to move across the window 34, a spring which urges the diaphragm 28 and signal element 50 in one direction, the diaphragm 28 being mounted to snap in one direction or the other when the pressure reaches a critical point, and a screw 41 for varying the compression on the spring without altering the position of the signal element 50. The diaphragm 28 is clamped between the base 20 and the bonnet 30, which has windows 34 on opposite walls. Resting on the diaphragm is a cup member 50 of green plastic, into which telescopes an inverted cup member 43 of red plastic, the cups being held apart by the spring which is supported in the bonnet against upward movement by a flange 42 and threads into a nut 44. The bonnet 30 is covered by a transparent hood 36, the thread 37 of which permits restrictive communication with the atmosphere. In the position shown the indicator is in the warning position with the diaphragm in its lowermost position since it is subject to a pressure lower than the critical value. In this position the red cup 43 is visible through the windows 34. When the pressure rises above the critical value, the diaphragm which is of larger area than the recess 26 which it covers, snaps over and raises the green cup 50 to cover the red cup 43 and be visible through the windows. In a modification the nut 44 is made integral with the upper cup 43. The indicator is described in combination with a domestic liquefied petroleum gas dispensing system, such as that described in Specification 811,915.