GB1499100A - Measuring fluid pressure - Google Patents

Abstract

1499100 Measuring fluid-pressure ENGLISH ELECTRIC CO Ltd 27 Jan 1975 [2 Nov 1973] 50995/73 Heading G1L A device enabling measurement of the pressure of a fluid which is at too high a temperature for contact with the gauge, e.g. molten sodium in a reactor, comprises a pressure balancing device 17 having an inlet 18 for the fluid to be measured, a second inlet 19 connected to the gauge 16 and via a valve 22, to a source 20 of pressurized balancing fluid at a greater pressure than the pressure to be measured. The device includes a piston having elements 28A, 28B slidable in a cylinder 24 having an outlet permitting exhaust of fluid between the elements, the fit of at least one element in the cylinder permitting leakage. In the arrangement exemplified, a pump (not shown) in a vessel 11 containing molten sodium and an inert gas 13, pumps sodium from the vessel, a by-pass 15 from the pump discharge supplying sodium to the pump bearing via a filter 14. The by-pass is connected to the inlet 18 of the device so that the delivery pressure is applied to the piston element 28B. In taking a reading, the higher pressure from the source 20 is applied to the piston forcing it to its lowest position, as shown. The valve 27 is shut and the higher pressure fluid leaks past the piston element 28A to above the sodium through ports 25. When the pressure above the. piston drops to that of the sodium in the by-pass, the piston rises and during its ascent, a constant reading is observed on the gauge which is the desired value.