GB1408034A - Steam traps of the free float type - Google Patents

Abstract

1408034 Steam traps K FUJIWARA 6 Sept 1972 [10 Sept 1971] 41412/72 Heading F4U [Also in Division G3] In a free float type steam trap the discharge of condensate through a passage 5 from a sump 4 to an outlet port 3 is controlled by a piston valve 15 movable and extending axially within a passage 11 formed in a valve seat member 9, the valve 15 having a passage 22 therethrough leading from a pilot valve port 21 closable by the float 8 to a pressure chamber 19 bounded by a valve seat holder 13 screwed to the side wall of the trap body 1 and by a piston disc 17 secured to the valve 15. The disc 17 has one or more orifices 20 interconnecting the pressure chamber 19 and the passage 11. In operation, condensate flow through a filter 36 of spaced and superposed annular plates from an inlet 2 into the sump raises the float and allows discharge through the passage 21;into the pressure chamber with sufficient force and generation of steam by evaporation due to the elevated temperature therein to react on the disc 17. As a result the piston valve 15 is moved to open a valve port 10 in the member 9 to allow condensate to discharge through the passage 11. A small amount of condensate moves the float upwardly a sufficient distance to allow a small degree of opening of the pilot valve port 21 so that the force with which the condensate discharges into the pressure chamber 19 is too low to open the piston valve 15, but the temperature within the chamber 19 is maintained at a high level. The steam trap also includes a manually operable needle valve 26 screwed into an exhaust valve seat 25 in a passage 24 in an upper cover 6 connecting the float chamber to the outlet passage 5, and a bimetallic disc valve 31 controls the outlet of steam through a valve port 32 in the seat 25.