Gas flow control valves comprising a valve housing including a cylindrical interior passage, and a housing opening extending from the interior passage through the housing. The gas flow control valve further comprises a cylindrical rotary valve element including a sidewall, and a rotary valve element opening extending through the sidewall. The valve element is rotatably received within the interior passage of the valve housing, such that the housing opening may be selectively aligned with the rotary valve element opening, and an area of overlap of the housing opening and the valve element opening may be varied by rotating the valve element within the interior passage of the valve housing.

The present variations disclose an apparatus for controlling fluid flow including funnel defining a first flow passage therethrough; a flow control valve defining a second flow passage in fluid communication with the first flow passage; and an attachment cap removably connected to the flow control valve, the attachment cap defining a third flow passage in fluid communication with the second flow passage and the first flow passage.

A gas appliance comprises a combustion device, an ignitor, a gas valve, a blower, a detecting device, and a control device. A control method thereof comprises: the control device is operated in a detection mode in which the control device controls the ignitor to ignite and controls the gas valve as well as the blower to provide a fixed gas flow and a fixed air flow to the combustion device. After igniting the flames, the control device determines burning states detected by the detecting device; if matching a first state, the control device controls the gas valve and the blower in correspondence to a first control data of the first natural gas; if matching the second state, the control device controls the gas valve and the blower in correspondence to a second control data of the second natural gas. In this way, the gas appliance is suitable for burning natural gas generating various heating values.

A plug member of a gas valve, having an axial bore, a first bore and a second bore located in a radial direction thereof to respectively communicate with the axial bore, and a first guiding slot and a second guiding slot recessed into an outer peripheral surface thereof. The first bore is larger than the second bore, and communicates with one end of the first guiding slot, while another end thereof is near the second bore. The first guiding slot becomes narrower from the first end to the second end. The second guiding slot has one end communicating with the second bore, and another end located between said first end and said second end.

A gas grill is disclosed having a gas control valve with a push to sear feature. The gas control valve has a housing with a valve core rotatably disposed within the housing. A sear valve is disposed within the valve core. A user rotates the valve core within the housing to selectively align a gas inlet port with a inlet passage and to align a sear gas port a the sear gas flow passage. The sear valve has a sear valve element which is selectively movable relative to the valve core to selectively pass a sear gas through a sear gas port and a sear flow passage to the forward end of the valve housing, and then to the grill. A bias member, preferably a coil spring, is mounted between the sear valve element and the valve core for urging the sear valve element to a closed position.

A valve assembly, includes a valve body having an inlet portion, an outlet portion, and a constriction portion; a shaft positioned within the valve body and extending along a longitudinal axis of the valve body; a cone provided within the inlet portion and configured to move along the shaft; a spring configured to bias the cone away from the constriction and positioned between a first piston fixed to the cone and a second piston fixed to the shaft; and an adjustable spacer positioned between a fixed position on the shaft and the second piston. The adjustable spacer is adjustable in length to change an effective length of the adjustable spacer and change a position of the second piston on the shaft.