GB779338A - Improvements in or relating to water level indicators for steam boilers - Google Patents

Abstract

779,338. Indicating liquid levels. JERGUSON GAGE & VALVE CO. April 12, 1956, No. 11187/56. Class 123 (1). The water level in a steam boiler is indicated by a differential manometer M to the opposite sides of which are applied through conduits 31, 33 and 17, 25, 27, respectively, a variable head proportionate to the height of water and a predetermined constant head. As shown the pipe 17 enters a cup 15 which is supplied with steam from the boiler drum B after its passage through a condenser 19, the condensate in the cup 15 being maintained at a level H, preferably slightly above the high water level NHW, by an overflow 21 ; the pipe 17 is also surrounded by a jacket 23, extending down to the normal operating level, through which steam circulates so that the water in the pipe is maintained at the temperature of the boiler water. On the other hand the pipe 31 is connected to the drum B at an opening 29 at a level L which is at the same distance h below the normal operating level as the level H is above it. With the pipes 31, 33 and 25, 27 at atmospheric temperature, the arrangement is such that when the boiler water is at the operating level the manometer always indicates that fact at the same point on its scale whatever the temperature and pressure conditions within the boiler. In modifications, (1) the jacket 23 is dispensed with, the pipe 25 enters the boiler drum at the normal operating level, and the cup 15 and pipe 17 are disposed within said drum, and (2) the jacket 23 is again dispensed with, the pipe 17 entering the boiler drum at the normal operating level and returning at the same level L as the pipe 31.