Patent GB-818245-A (GB)
Title: Diaphragm-controlled gas pressure regulator
IPC: G05D16/06
Filed: 1955-12-08
Abstract: 818,245. Valves. KROMSCHRODER A.G., G. Dec. 8, 1955 [Dec. 9, 1954], No. 35261/55. Class 135. In a diaphragm-controlled gas pressure regulator a hollow valve-seat body forming externally with the valve casing an outlet duct concentric with an inlet duct through the valve-seat body is provided with two valve seats cooperable with independently diaphragm-controlled valve closure members. As shown in Fig. 1, a two-stage gas pressure regulator comprises a valve casing 1 fitted with a valve-seat body 3 having an inlet duct 4 and between it and the valve casing a concentric outlet duct 5. The body 3 is formed internally with a first seat 16 co-operable with a first valve closure member 15 under the control of a spring-loaded diaphragm 14 subject to pressure downstream of the valve 15, 16 and externally with a second seat 9 co-operable with a second valve closure member 8 under the control of a diaphragm 7 loaded by a weight 6. Gas after passing the first valve is deflected downwardly by a plate 21 carried by the diaphragm 14 to act on a diaphragm 11 in opposition to outlet pressure from the second valve acting on the diaphragm 7. A venturi passage 22 in the outlet duct reduces the outlet pressure so that a larger pressure than would otherwise be the case is necessary to close the valve 8. In another embodiment, diaphragms 14, 7 are replaced by a single diaphragm 27, Fig. 2, having an inner portion controlling a first valve member 30 and connected to an extension 26 of the valve-seat body 24, an outer portion I controlling a second valve member 32 and an intermediate portion II which replaces the diaphragm 11 and is effective to balance the pressure on the projected upper face of the valve member 32. A passage between a skirt 33 formed on the valve member 32 and the body 24 replaces the venturi passage. In a modification of the Fig. 2 embodiment, a safety cut-off valve 35, Fig. 3, co-operable with a further seat 34 on the valve-seat body 24 is fitted. The valve 35 is normally held by balls 40 in a bore in the first valve 30 to move with that valve. In the event of excessive outlet pressure transmitted through a tube 47 to a chamber 46 closed by a diaphragm 44, a sleeve 41 carried by the diaphragm moves upwardly to permit release of the balls 40 and a spring 39 to close the valve 35. Gas within the chamber 46 escapes to atmosphere and removal of a cover 53 allows manual resetting of the valve 35. Fig. 6 shows a one-stage gas pressure regulator having a valve closure member 62 co-operable with either of seats 58, 60 to regulate the flow of gas or cut it off on a deficiency of supply and a safety cut-off valve 63. A diaphragm 61 controls the valve 62, and a diaphragm 69 the valve 63, whilst a diaphragm 67 is effective to balance the pressure acting on the projected upper surface of the valve 63. An extension 37<SP>1</SP> on the stem of the valve 63 carries a valve disc 74 which cooperates with a seat 73 on a diaphragm 72 to seal the valve casing against leakage when the safety cut-off valve 63 is seated. In order that the valve may again operate when the deficiency of gas supply ceases a leakage notch 75 is provided in the valve 62.