GB505717A - Improvements in or relating to valves - Google Patents

Abstract

505,717. Combined pressure-reducing and stop valves. COMPAGNIE POUR LA FABRICATION DES COMPTEURS ET MATERIEL D'USINES A GAZ. May 5, 1938, No. 13482. Convention date, May 5, 1937. [Class 135] A combined pressure-regulating and stop valve has a single valvo member 7 which is actuated automatically by the difference in pressure between the inlet and outlet sides of the valve acting on a differential piston 6, 6a and is actuated positively in each direction by a screwed operating spindle 20 connected to the valve member solely through the valve loading spring 19. The differential piston comprises a lower member 6 surmounted by an upper flanged member 6a which separates packings 9, 10 sliding in cylinders 5, 5a of different diameter formed in the valve casing. The assembly of pistons and packings is held in place by a nut 12. The valve member 7 has an axial passage 29 opening into an axial passage 16 in the piston 6 and is screwed into the latter to hold a valve packing 26 in place. It also has a ported tubular extension 24 sliding through the valve seat aperture 4 in the partition 3 separating the inlet and outlet chambers 1, 2. The valve casing is closed by a bonnet 18 made fluid-tight by packings 32, 33 and carrying the screw spindle 20. The loading spring 19 abuts a shoulder 21 on the spindle 20 and a flange 22 on the piston 6. When the spindle 20 is screwed down to the fullest extent, it holds the valve closed positively and conversely when screwed up to the fullest extent, it compresses the spring 19 and holds the piston 6a against the bonnet 18 so that the valve is held open positively. In the intermediate positions, the spring 19 is stressed more or less to regulate the pressure maintained in the outlet 2. The chamber 14 between the pistons is open to the atmosphere through a port 15. The valve packing 26 may be replaced by a ground conical surface and the ports 28 may be oval or circular. The valve may be of double beat form. According to the Specification as open to inspection under Sect. 91, the upper packing 10 may be replaced by a diaphragm clamped to the casing, the chamber 14 in this case being so large that the aperture 15 may be omitted. This subject-matter does not appear in the Specification as accepted.