GB798496A - Improvements in telemetering systems - Google Patents

Abstract

798,496. Fluid-pressure servomotor-control systems. BAILEY METERS & CONTROLS, Ltd. July 27, 1956 [July 29, 1955], No. 23280/56. Class 135. Relates to a fluid-pressure telemetering relay 22, 23, 24 or 29 installed in the wall 1 of a sealed container enclosing nuclear steam generating plant 4, 9, the relays 22, 23, 24 outwardly transmitting signal pressures 19, 20, 21 from meters 13, 14, 15 sensing respectively boiler feed rate, differential pressure between two points above and below normal water level in the boiler 9, and steam flow, to an external signal-receiving panel 16 through respective pipes 25, 26, 27, whilst the relay 29 transmits a resulting inward signal from the panel 16 between pipes 28, 30 leading to an internal feed water control valve 12. Each relay, e.g. 29, comprises a body 40 mounted in and sealing, an aperture in the wall 1, and having input and output pressure chambers A, D, sealed by flexible diaphragms 44, 46, and at least one (two shown) interposed chamber B, C through which passes a plunger 47 connecting the diaphragms together and to a lever 53 operating valves 49, 50 respectively admitting or exhausting pressure air to or from the output chamber D in accordance with variation in signal pressure in the input chamber A, whereby pressure in the output pipe 30 is maintained always equal to signal pressure in the pipe 28. Exhaust from the output chamber D is into the sealed container for the inward relay 29, and outside for the outward relays 22, 23, 24. Flexible bellows 52, 51 respectively seal the chamber C from B, and A from the atmosphere. Return springs opposing signal pressure are provided at 48, 54. In a " standardization " relay, Fig. 3, not shown, the chamber C bleeds permanently to D and an additional bellows connects the casing wall 45 with the diaphragm 44. The air pressure sources outside and inside the wall 1 may be separate or a single external source may be used. The three meters 13, 14, 15, operate pilot valves through linkage in accordance with Specification 425,507, [Group XII], and the telemetered pressure outputs, recorded at 17 on the control panel 16, operate relays as described in Specification 739,501 or 461,389, the resultant pressure 28 operating the feed valve 12. A manual selector valve 18 cuts out automatic control, substituting manual control.