GB1338743A - Meter prover apparatus and method - Google Patents

Abstract

1338743 Meter proving device M H GROVE and J M E GROVE [trading as M & J DEVELOPMENT CO] 6 July 1972 [28 July 1971 27 Sept 1971] 31819/72 Heading G1B A tight fitting sphere 1 or 2 is propelled through a metering tube having an inlet 9a and an outlet 9b by the flow to be measured and the time taken for the sphere to pass from detector 10 to detector 11 measured, the spheres being collected from outlet 9b and injected into inlet 9a by an interchange 13. The interchange includes a sleeve 15 in which the spheres are a tight fit, a plunger 23 having a pair of opposed cup shaped seals 27, 28 Fig.7 for forming a seal with the sleeve and a guard 63 slidable along the rod 22 mounting the plunger 23 and resting on a stop 64 when the plunger is within the sleeve. The liquid to be metered enters at T-piece 20 and exits at T-piece 12 through pipe 18. A by-pass 21 connects the T-piece 14 with pipe 18. From the position shown in Fig.1, the plunger 23 is moved downwardly by means of hydraulic ram 24 Fig.4 to inject sphere 1 into the flow, and the sphere is carried around the metering tube and emerges from outlet 9b into T-piece 12. Ribs 19 guide the sphere 1 along T-piece 12 so that it abuts guard 63, a vertical rib 19a pushing the sphere off centre to prevent it being held stationary over pipe 18 by the liquid flow. The plunger is then raised to the top of the T-piece 14 by hydraulic ram 24, the guard 63 being lifted upwardly by the plunger. Sphere 2 rises with the plunger until the seal with sleeve 15 is broken, and when the guard moves upwardly sphere 1 rolls on to sphere 2. Downward movement of plunger 23 then reproduces the arrangement of Fig.1 with the positions of spheres 1 and 2 interchanged. The seal of the plunger to the sleeve 15 is tested each cycle by a pressure switch 41 connected to the space 33 between the sealing cups 27, 28. As the plunger moves downwardly, a switch 93 is operated to actuate solenoid vent valve 40 for a short time, and then operation of switch 41 indicated leakage into space 33. Leakage past the spheres may also be determined by means of an orifice 57 in sleeve 15 connected to a pressure switch 61 and a solenoid vent valve 58 which may vent to atmosphere or to a higher pressure. The spheres may be removed through a cover 17, and liquid may be passed into sleeve 15 via valve 62 and orifice 57 to aid recovery of the second sphere. The guard 63 may be a tight sliding fit on the plunger rod 22 Fig.8 (not shown) or an alternative pivoting guard arrangement may be used Figs. 9 and 10, (not shown). The T-piece 12 may be sloping Fig. 11 (not shown) or the interchange may be arranged generally horizontally Figs.13 and 14 (not shown). A control circuit Fig.12 (not shown) is described for automatically taking the device through one cycle on actuation of a switch, the beginning and the end of the cycle corresponding to the uppermost portion of the plunger.