Stop valve

A fully automatically operable pneumatic stop valve is provided which rests on the principle of pressure differences in its various membrane spaces in controlling the fluid flow through the valve, wherein the rising fluid closes a fluid level control pipe and thereby upsets the pressure conditions in an auxiliary valve membrane space which in turn controls the pressure in the main membrane space controlling the closing of the main valve.

We claim:

1. A stop valve of the liquid level sensor type comprising a housing having an input stub, an exit opening (21) formed as a valve seat, characterized by a membrane space (1) opening upwardly and located in the valve housing (41), an auxiliary valve housing (42) with a membrane space (2) opening downward, on the upper side of the auxiliary valve housing (42) there is formed a membrane space (4) opening upward, and communicating with the lower membrane space (2) of the auxiliary valve housing (42) through a passage including the auxiliary valve seat (17), the auxiliary valve housing (42) is closed by a valve cover (43) including a membrane space (5) opening also downward, and the membrane spaces (1,2) located between the valve housing (41) and the auxiliary valve housing (42) are separated from each other by a membrane (3) carrying a main valve disc (14) and having a transit flow opening (23) therethrough, the membrane spaces (4,5) located between the auxiliary valve housing (42) and the valve cover (43) are separated from each other by a membrane (6) carrying auxiliary valve disc (7), a liquid level sensor means located within the valve housing and comprising said exit opening (21) constructed in a tapered fashion and extending beyond a portion of a suction pipe (11) and to the bottom part of which said suction pipe (11) reaching to the desired fluid level at the other end thereof is connected and, is in communication with the membrane space (5) located in the valve cover (43), said tapered exit opening (21) exerting an injector-like suction effect through said suction pipe (11) for sucking in only air as long as the mouth of said suction pipe (11) is open, the membrane space (4) located at the upper side of the auxiliary valve housing (42) communicates with a fluid removal passage (20) when the rising fluid level closes the lower opening of said suction pipe (11), a low pressure condition is created in the membrane space (5) of the auxiliary valve housing (42) for closing said auxiliary valve disc (7), when the pressure increases in membrane space (2) for forcing the membrane (3) with the disc (14) thereof against the valve seat of exit opening (21), thereby closing said main valve disc 14.

2. The stop valve according to claim 1, characterized by spreading means (46) formed at the lower end of an exit pipe (13) located under the exit opening (21) for the horizontal spreading of the fluid, the lower end of the suction pipe (11) is surrounded by a wave breaking pipe (45).

3. A stop valve of the liquid level sensor type comprising a housing having an input stub, an exit opening formed as a valve seat, characterized by a membrane space (1) opening upwardly and located in the valve housing (41), an auxiliary valve housing (42) with a membrane space (2) opening downward, on the upper side of the auxiliary valve housing (42) there is formed a membrane space (4) opening upward, and communicating with the lower membrane space (2) of the auxiliary valve housing (42) through an opening including the auxiliary valve seat (17), the auxiliary valve housing (42) is closed by a valve cover (43) including a membrane space (5) opening also downward, and the membrane spaces (1,2) located between the valve housing (41) and the auxiliary valve housing (42) are separated from each other by a membrane (3) carrying a main valve disc (14) and having a transit flow opening (23) therethrough, the membrane spaces (4,5) located between the auxiliary valve housing (42) and the valve cover (43) are separated from each other by a membrane (6) carrying auxiliary valve disc (7), the exit opening (21) is constructed in a tapered fashion, to the bottom part of which a suction pipe (11) reaching to the desired fluid level, is connected on one hand, and on the other hand to a branch suction pipe (22) which is in communication with the membrane space (5) located in the valve cover (43), the membrane space (4) located at the upper side of the auxiliary valve housing (42) communicates with a fluid removal passage when the rising fluid level closes the lower opening of said suction pipe (11), a low pressure condition is created in the membrane space (5) of the auxiliary valve housing (42) for closing said auxiliary valve disc (7), when the pressure increases in membrane space (2) for forcing the membrane (3) with the disc (14) thereof against the valve seat of exit opening (21), thereby closing said main valve disc (14), said stop valve being operable also as a level regulator, characterized by an overflow reservoir (26) placed at the bottom of an exit pipe (13) communicating with the exit opening (21), to the bottom of the overflow reservoir (26) there is connected with its one end a dual U-pipe (27) having legs of different length and communicating with membrane space (5) located in the valve cover (43) at its other end, the upper-lying bottom part of which is provided with a bleeder spout (29), and the top part of which is provided with a bleeder pipe (30).??/%%/?/)&