A valve assembly for a vehicle exhaust system includes an exhaust component body defining an exhaust gas flow path and a flap mounted to pivot in the exhaust gas flow path between a minimum flow position and a maximum flow position. At least one bushing supports the flap for rotational movement relative to the exhaust component body about an axis. In one example, a damper is positioned radially between the bushing and the flap and defines an inner diameter that is smaller than an outer diameter of the bushing. In another example, a damper is attached to the flap such that a distal edge is free from attachment to a distal edge of the flap such that as the flap returns to the minimum flow position the damper first contacts the exhaust component body and then the flap contacts the damper.

The present disclosure provides a rain cover assembly, a pipe assembly and a turbine fracturing unit. The rain cover assembly comprises at least two sets of cover plate assemblies, wherein each set of cover plate assembly comprises a cover plate, a transmission mechanism and a locking device. When the cover plate(s) is(are) at a closed position, the opening is covered; when the cover plate of each set of cover plate assembly is at an open position, an additional pipe structure which is open at both ends and extends along an extension direction of the pipe is formed by which. According to the present disclosure, the cover plate(s) of the rain cover assembly, when opened, will jointly form an additional pipe structure connected to the open end of the pipe to guide the exhaust gas of the pipe to a further space. Such an arrangement may reduce noise on the one hand, and prevent backflow of the exhaust gas on the other hand. The cover plate(s) of the rain cover assembly, when closed, can shield the opening of the pipe to prevent entry of rainwater.

An exhaust structure for a saddle riding vehicle includes: an exhaust pipe connected to an internal combustion engine; and a catalyst disposed in the exhaust pipe; the exhaust pipe including a catalyst case unit housing the catalyst and upstream side exhaust pipes disposed on an upstream side of the catalyst case unit; the catalyst case unit having a larger diameter than the upstream side exhaust pipes; the upstream side exhaust pipes being connected to the catalyst case unit in a connecting portion located on an upstream side of the catalyst in a flow of exhaust; in the connecting portion, axes of the upstream side exhaust pipes and an axis of the catalyst case unit being in substantially right-angled positional relation to each other.

A water drainage assembly for an aftertreatment system comprises a first tube structured to be coupled to an outlet conduit of the aftertreatment system and has a first cross-sectional width. A second tube is disposed radially around the first tube. A first end of the second tube is coupled to a radially outer surface of the first tube. A portion of the second tube has a second cross-sectional width larger than the first cross-sectional width such that a volume is defined between the first and second tubes. A drain port is defined in the second tube proximate to the first end. The assembly is structured such that water flowing into the water drainage assembly flows into the volume defined between the first tube and the second tube and is expelled therefrom via the drain port.

A cover for a DEF assembly with openings dimensioned to receive various components that are positioned in the DEF holding tank and associated seals for closing the openings and retaining the components is disclosed. The seals are fixed to the cover by a sonic weld.

A vehicle exhaust system includes an exhaust component comprising a wall having an outer surface and an inner surface that defines an internal exhaust component cavity. At least one hole is formed in the exhaust component to extend through the wall of the exhaust component from the outer surface to the inner surface. A membrane is configured to overlap the at least one hole, wherein the membrane is moveable relative to the wall in response to pressure fluctuations.

A cover for a DEF assembly with openings dimensioned to receive various components that are positioned in the DEF holding tank and associated seals for closing the openings and retaining the components is disclosed. The seals are fixed to the cover by a sonic weld.

A water drainage assembly for an aftertreatment system includes: a tube having an inlet structured to be coupled to an outlet conduit of an aftertreatment system; a drain port extending through the tube; a first baffle disposed in the tube, a first baffle first end attached to an inner surface of the tube at a first location, wherein at least a portion of the first baffle is inclined downwards with respect to gravity; and a second baffle disposed in the tube below the first baffle, a second baffle first end being coupled to the inner surface of the tube at a second location that is opposite to and below the first location, wherein at least a portion of the second baffle is inclined upwards with respect to gravity.

Disclosed is a water ingress preventive structure for a tailpipe which discharges exhaust gas outside of a vehicle at a terminal of an exhaust passage system. A curved shape is imparted to the tailpipe. A partition is mounted on an inner periphery of a curved portion outward of a curved direction so as to be gradually spaced apart from the inner periphery toward downstream in a direction of flow of the exhaust gas. Thus, a dead end portion is defined by the partition and the inner periphery of the curved portion outward of the curved direction.

A cover for a DEF assembly with openings dimensioned to receive various components that are positioned in the DEF holding tank and associated seals for closing the openings and retaining the components is disclosed. The seals are fixed to the cover by a sonic weld.