A first casing has an internal cylindrical region defined as a floating/sinking guiding region for a float valve. The wall that forms the cylindrical region includes ventilation windows. A second casing surrounds the first casing to form, about the periphery of the first casing, a ventilation passage that guides fuel vapor in a fuel tank to the ventilation windows through a region that surrounds the first casing. In addition, the second casing surrounds the first casing from a first connection hole side to form, about the periphery of the first casing, a first ventilation passage that guides the fuel vapor in the fuel tank to the ventilation windows through the region that surrounds the first casing, and a second ventilation passage that has a larger passage cross-sectional area than the first ventilation passage. These ventilation passages stabilize floating/sinking operation of the float.

The mounting structure of a fuel device is for mounting the fuel device, which includes a plurality of components, on a baffle plate for suppressing waving of liquid fuel stored in a fuel tank. One of the components of the fuel device is integrally formed, as a mounting portion, with the baffle plate. The remaining components of the fuel device are mounted, as a mounted portion, on the mounting portion of the baffle plate.

A ventilation control valve for a fuel tank is disposed in a ventilation passage which communicates an inside and an outside of a fuel tank. The ventilation control valve includes a float that floats on a liquid level of a fuel and moves up and down. The ventilation control valve includes a valve mechanism which switches a passage sectional area of the ventilation passage in conjunction with the float to an open state and a restricted state in which the passage sectional area is restricted from the opened state. The float has a volume chamber in which volume changes in accordance with a vertical movement of the float. A control gap as a flow rate adjusting mechanism is formed between the cylindrical wall of the float and the cylindrical wall of a case. Due to the control gap, the volume chamber functions as a damper.

A fuel tank valve having: a housing that is arranged in a fuel tank and has a communication port communicating with an outside of the fuel tank; and a float valve body that is installed in the housing and closes the communication port when fuel in the housing increases, where a wall part of the housing has an opening part through which the fuel flows in and out, and a projecting part that is formed to correspond to the opening part and projects outwardly from the wall part, and the projecting part is separated above from the opening part by a predetermined distance, is provided.

A water level controller for a hydroponic system includes a float shifting upward and downward with the culture solution, a first magnetic attraction element and an inlet valve for feeding in the culture solution. The float includes a seal and a second magnetic attraction element. The seal closes the inlet valve to stop feeding in water when the float ascends to a high water level, and moves way from the inlet valve to start feeding in water at a low water level. The second magnetic attraction element attracts the first magnetic attraction element to keep the seal closing the inlet valve at the high water level and to keep the seal moving away from the inlet valve at the low water level, until the buoyancy of the float is larger than the magnetic attraction between the second and the first magnetic attraction element thereby causing escape from each other.

The present invention discloses an improved operating fluid reservoir having a venting and/or air admission valve. The operating fluid reservoir is characterized in that a valve housing is formed integrally with an operating fluid reservoir wall. A vent opening, via which a valve housing interior is in fluid communication with a vent line, is embodied as a through opening through the operating fluid reservoir wall. A valve body, which is arranged in the valve housing interior, can be introduced into the valve housing interior via an introduction opening in the valve housing. The valve body comprises a holding device, by which the valve body is held movably in the valve housing.

A water hammer-proof air valve that has a valve body and a bonnet, that are fixedly connected, a valve opening is provided on the valve body, and a high-speed intake and exhaust device is provided in an inner cavity of the valve body. A bonnet opening is provided on the bonnet, an output end of the high-speed intake and exhaust device penetrates the bonnet opening and is communicated with a high-speed exhaust throttling device for limiting an exhaust amount of gas of the high-speed intake and exhaust device, an output end of the high-speed exhaust throttling device is communicated with an outside air, and a trace exhaust device for discharging the gas separated out from the pipeline to the outside through the high-speed exhaust throttling device after the high-speed intake and exhaust device closes the valve is further provided in the high-speed intake and exhaust device.

A vent control valve includes: a first case shaped in a tube that forms a passage for ventilation; a movable valve object arranged in the first case to open and close the passage; an inner case arranged in the first case to support the movable valve object; a second case disposed at a lower end of the first case; a first connection mechanism defined between the first case and the inner case, the first connection mechanism connecting the first case and the inner case with each other; and a second connection mechanism defined between the first case and the second case, the second connection mechanism connecting the first case and the second case with each other.

In a valve device for a fuel tank, a fuel liquid level of filling-up fuel feed and an allowable fuel amount of additional fuel feed can be easily and appropriately changed by replacing only a part of components forming the valve device. A first valve chamber has a structure of positioning an open end below a support portion of a first float having a passage portion for a fluid. A second valve chamber includes a support portion of a second float having a passage portion for the fluid. The first valve chamber and the second valve chamber are formed by fitting a lower-portion including the support portion and the open end of the first float and the support portion of the second float relative to an upper-portion including a first valve opening and a second valve opening.

The mounting structure of a fuel device is for mounting the fuel device, which includes a plurality of components, on a baffle plate for suppressing waving of liquid fuel stored in a fuel tank. One of the components of the fuel device is integrally formed, as a mounting portion, with the baffle plate. The remaining components of the fuel device are mounted, as a mounted portion, on the mounting portion of the baffle plate.