A snap-action valve assembly includes a valve flap positioned within a conduit for controlling exhaust flow through the conduit. A shaft supports the valve flap in the conduit for rotation about a pivot axis between a closed position and an open position. A guide is fixed to the valve flap. A torsion spring is positioned at least partially outside the conduit and includes a first end restricted from rotation in at least one direction. The torsion spring includes a second end coupled to the guide. The torsion spring is preloaded to urge the valve flap into contact with an inner surface of the conduit when the valve flap is in the closed position.

A snap-action valve assembly includes a valve flap positioned within a conduit for controlling exhaust flow through the conduit. A shaft supports the valve flap in the conduit for rotation about a pivot axis between a closed position and an open position. A guide is fixed to the valve flap. A torsion spring is positioned at least partially outside the conduit and includes a first end restricted from rotation in at least one direction. The torsion spring includes a second end coupled to the guide. The torsion spring is preloaded to urge the valve flap into contact with an inner surface of the conduit when the valve flap is in the closed position.

A snap-action valve assembly for an exhaust system includes a valve flap positioned within a conduit. A shaft supports the valve flap in the conduit for rotation about a pivot axis between a closed position and an open position. A roller is supported for rotation on a post. The post is fixed to the shaft by a lever arm. A torsion spring includes a first end coupled to the conduit and a second end coupled to the roller. The torsion spring is preloaded to urge the valve flap into contact with an inner surface of the conduit when the valve flap is in the closed position. A method of assembling the snap-action valve assembly with a predetermined spring preload torque is also discussed.

An exhaust pipe valve system of an internal combustion engine includes: a plurality of exhaust pipe valves; and an actuator unit being an operation unit which performs an opening/closing operation of the exhaust pipe valves, wherein: the operation unit includes a first pulley and a second pulley being at least two operation parts which are connected to the plural exhaust pipe valves via wire cables respectively to open/close the exhaust pipe valves; and at least one of the operation parts has a non-operating area in which the operation part does not cause the corresponding cable to work in a predetermined operating range of the operation unit.

An assembly and method for operating actuators, the assembly including a control device with at least a first control device part and a second control device part, wherein the first control device part is connected at least indirectly to a first actuator and the second control device part is connected at least indirectly to a second actuator. The method including a control device provided with a first control device part and a second control device part, wherein the first control device part controls a first actuator and the second control device part controls a second actuator simultaneously, wherein control is accomplished wherein at least a first condition, in which the first and second actuators are closed simultaneously, and a second condition, in which the first actuator is closed and the second actuator is opened or the first actuator is opened and the second actuator is closed, can be controlled.

An ice-melting exhaust diverter with selectable flow control is disclosed. The ice-melting exhaust diverter includes an exhaust inflow opening configured to receive exhaust from an internal combustion engine, a first exhaust outflow opening configured to release exhaust rearward, a second exhaust outflow opening configured to release exhaust downward, and a diverter plate having a selectable control to direct exhaust flow rearward or downward through either the first outflow opening or the second outflow opening, respectively.

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.