GB1386239A - Pressure testing - Google Patents

Abstract

1386239 Pressure gauges; leak testing UNITED GAS INDUSTRIES Ltd 1 May 1972 [28 May 1971] 18104/71 Headings GIL GIR and GIS The liquid reservoirs 6 of a plurality of monometers are inter-connectable by the opening of valves 3, and hence when subjected to a common reference pressure the liquid levels in the manometer tubes 1 attain a common level to which a cursor 7 may be set. When the valves 3 are then shut and pressure sources connected to each of the reservoirs via inlet ports 2, a variation in the pressure of one source is detected by a change of liquid level in its associated tube 1. The pressure sources may be pressurized vessels, e.g. gas meters 15 pressurized at the reference pressure by a common source 10, a fall in liquid level in one tube 1 thus indicating a leak in a vessel. Alternatively to detect leakage into a vessel the vessel is placed in a pressurized compartment and the compartment connected to a manometer. Errors due to irregularities in the internal dimensions of the tubes 1 are thus eliminated and temperature changes can be compensated for simply by moving the cursor 7. In addition the tubes 1 can be inclined, e.g. by 30 degrees, to increase the sensitivity and resolution of the manometers.