A vent valve includes an outer frame, a ventilation box movable in the outer frame, a sealing cover, a buoyant box and elongate sliding members. The ventilation box has an interior space. The sealing cover has a cover opening, and closes/opens a surrounding space defined by the ventilation box and the outer frame. The buoyant box is disposed within the interior space. When the buoyant box abuts the sealing cover and closes the cover opening, the cover opening is disconnected from the interior space. When the buoyant box moves away from the sealing cover, the interior space communicates the cover opening. The sliding members slidingly contact the outer frame and ventilation box to guide sliding movements.

Irrigation valves for channels and for irrigation tanks are of three types. All are activated by a pair of tilting float arms to which a pair of floats are attached. One type is a T-shaped duct with a cylindrical valve disposed at 90 degrees to the part that is connected to the incoming flow. The floats rotate the valve. The second type has the same construction as the first type, thereby giving flow control but additionally has a rise and fall gate in the duct part that is connected to the incoming flow. The gate acts as a stop valve. The third type has a cylindrical duct connectable to the incoming flow but no valve and provides both flow control and stop valve facilities through a rise and fall gate actuated by the tilting of the float arms.

A venting and/or bleeding valve with a valve housing, a main valve arranged in the valve housing for rapid venting and bleeding of piping connected to the valve housing, an auxiliary valve arranged in the valve housing for operating ventilation of the piping at operating pressure, and a float arranged within the valve housing and controlling the main valve and the auxiliary valve as a function of the filling level of a fluid located in the valve housing. The venting and/or bleeding valve contains a valve position sensor for acquisition of the position of the main valve, at least one additional sensor for acquisition of the humidity and/or the pressure and/or of the temperature in an interior space of the valve housing, and an evaluation unit for acquisition of an operating state of the venting and/or bleeding valve as a function of the values acquired by the valve position sensor and any additional sensor.

The present disclosure provides a return gas prevention device for a drainage pipe, belonging to the technical field of drainage pipes. The device realizes two functions of water seal and a check valve simultaneously, as well as prevents gas channeling in a drainage process.

A vent valve includes an outer frame, a ventilation box movable in the outer frame, a sealing cover, a buoyant box and elongate sliding members. The ventilation box has an interior space. The sealing cover has a cover opening, and closes/opens a surrounding space defined by the ventilation box and the outer frame. The buoyant box is disposed within the interior space. When the buoyant box abuts the sealing cover and closes the cover opening, the cover opening is disconnected from the interior space. When the buoyant box moves away from the sealing cover, the interior space communicates the cover opening. The sliding members slidingly contact the outer frame and ventilation box to guide sliding movements.

The present disclosure provides a return gas prevention device for a drainage pipe, belonging to the technical field of drainage pipes. The device realizes two functions of water seal and a check valve simultaneously, as well as prevents gas channeling in a drainage process.

A fully-integrated, flow-control module for top-fill fuel tanks operates with a fuel line attached that supplies fuel under pulsating pressure. There are two bleed paths in the module, which open and close sequentially in response to the position of a fuel float within the module. In order for a main valve plunger, which controls fuel entry into the tank, to fully close, both bleed paths must be closed. A first bleed path closes first, followed by closure of the second. For the main valve plunger to fully open, both bleed paths must be open. The second bleed path opens first. Movement of the main valve plunger is controlled by both a biasing spring and pressure beneath the plunger. Pressure beneath the plunger builds up to a level sufficient for the biasing spring to fully close the plunger against a valve seat when both bleed paths are closed.

A fully-integrated, flow-control module for top-fill fuel tanks operates with a fuel line attached that supplies fuel under pulsating pressure. There are two bleed paths in the module, which open and close sequentially in response to the position of a fuel float within the module. In order for a main valve plunger, which controls fuel entry into the tank, to fully close, both bleed paths must be closed. A first bleed path closes first, followed by closure of the second. For the main valve plunger to fully open, both bleed paths must be open. The second bleed path opens first. Movement of the main valve plunger is controlled by both a biasing spring and pressure beneath the plunger. Pressure beneath the plunger builds up to a level sufficient for the biasing spring to fully close the plunger against a valve seat when both bleed paths are closed.

A venting and/or bleeding valve with a valve housing, a main valve arranged in the valve housing for rapid venting and bleeding of piping connected to the valve housing, an auxiliary valve arranged in the valve housing for operating ventilation of the piping at operating pressure, and a float arranged within the valve housing and controlling the main valve and the auxiliary valve as a function of the filling level of a fluid located in the valve housing. The venting and/or bleeding valve contains a valve position sensor for acquisition of the position of the main valve, at least one additional sensor for acquisition of the humidity and/or the pressure and/or of the temperature in an interior space of the valve housing, and an evaluation unit for acquisition of an operating state of the venting and/or bleeding valve as a function of the values acquired by the valve position sensor and any additional sensor.