GB1149012A - Improvements in and relating to fluid flow regulators - Google Patents

Abstract

1,149,012. Fluid-pressure servomotor systems. HONEYWELL Inc. April 28, 1966 [May 18, 1965; July 22, 1965j, No.18802/66. Heading G3P. A fluid-pressure regulating valve having a uniform outlet pressure comprises a main valve 25, controlling the flow from an inlet 12 to an outlet 13, which is connected to a diaphragm 21 bounding a fluid-pressure chamber 23. The chamber 23 is connected to the inlet 12 through a restriction 37, on-off valve 33 and passage 44. The pressure in chamber 23 actuating the main valve is controlled by a pilot valve 55 actuated by a diaphragm 54 which is subjected to the pressure in the outlet chamber 15 through passages 42, 53. The diaphragm is loaded by a spring 70 which engages a sliding abutment 66 having a flange 67 movable between adjustable abutments 60, 61. The passage 47 from the chamber 23 is also connected through a restriction 74 to a chamber 72 above a diaphragm 56. In operation with the on-off valve 33 in the position shown, the chamber 23 is connected through valve 33, chamber 41 and passage 42 to the outlet, which is at atmospheric pressure and the valve 25 is closed by spring 26. If the on and off valve is now actuated, for example in response to temperature, the valve 33 moves upwards to open the chamber 23 to the inlet through the restrictor 37 and the main valve opens to allow flow to the outlet. The outlet pressure now acts through passages 42, 53 on diaphragm 54 to open the valve 55 at a predetermined outlet pressure which restricts the pressure in chamber 23. As the flow through restriction 74 to chamber 72 increases the pressure acting on diaphragm 56, the diaphragm moves the spring abutment 66 downwards to increase the loading of spring 70 and thus increase the regulated output pressure at 13. In a modification, the valve 55 is replaced by two valves in parallel one of which has a light loading and this valve is held closed after actuation of a diaphragm similar to 56, and the second valve has a greater loading to provide the higher output pressure. In a further modification, two control valves are used actuated in sequence by a temperature thermostat through a lever mechanism.