A butterfly valve is a valve that isolates or regulates the flow of a fluid. The closing mechanism is a disk that rotates. Operation is similar to that...

variations) is a valve controlling the release of a fluid. Tap is used in the United Kingdom and most of the Commonwealth for any everyday type of valve, particularly...

A valve is a device or natural object that regulates, directs or controls the flow of a fluid (gases, liquids, fluidized solids, or slurries) by opening...

Plug valves are valves with cylindrical or conically tapered "plugs" which can be rotated inside the valve body to control flow through the valve. The...

the valve timing is the precise timing of the opening and closing of the valves. In an internal combustion engine those are usually poppet valves and...

The sleeve valve is a type of valve mechanism for piston engines, distinct from the usual poppet valve. Sleeve valve engines saw use in a number of pre–World...

heart valves closing in a healthy 16 year old girl. The stethoscope is at the tricuspid area. Problems playing this file? See media help. A heart valve is...

their actuation in different directions. A desmodromic valve is a reciprocating engine poppet valve that is positively closed by a cam and leverage system...

Variable valve timing (VVT) is the process of altering the timing of a valve lift event in an internal combustion engine, and is often used to improve...

Woolf compound rotative beam engines built by Gimson and Company, Leicester. Bolton Steam Museum (Bolton, England) – includes several rotative beam engines...

A gate valve, also known as a sluice valve, is a valve that opens by lifting a barrier (gate) out of the path of the fluid. Gate valves require very little...

controls the operation of the intake and exhaust valves in an internal combustion engine. The intake valves control the flow of air/fuel mixture (or air alone...

A rotary valve (also called rotary-motion valve) is a type of valve in which the rotation of a passage or passages in a transverse plug regulates the flow...

Sequential Valve Timing, is an automobile variable valve timing technology developed by Mazda. S-VT varies the timing of the intake valves by using hydraulic...

A check valve, non-return valve, reflux valve, retention valve, foot valve, or one-way valve is a valve that normally allows fluid (liquid or gas) to...

Aspin in 1939, although the idea was devised before this time. The valve rotates to provide the opening and closing necessary for intake and exhaust...

blowoff valve (also called dump valve or compressor bypass valve) is a pressure release system present in most petrol turbocharged engines. Blowoff valves are...

perform this function. The oldest extant rotative steam engine, the Whitbread Engine (from 1785, the third rotative engine ever built), is located in the...

A safety valve is a valve that acts as a fail-safe. An example of safety valve is a pressure relief valve (PRV), which automatically releases a substance...

This was the 'Lap Engine', an early rotative engine now preserved in the Science Museum, London. With a rotative engine, it was necessary to control the...

A control valve is a valve used to control fluid flow by varying the size of the flow passage as directed by a signal from a controller. This enables the...

limitation of rotative speed or the number of revolutions which are caused by the need for engaging catches and valves can be a down fall in these valve-gears...

medieval period. Once the rotative version of the steam engine was developed in the late 18th century, the operation of the valve gear was usually by an...

Variable valve lift (VVL) is an automotive piston engine technology which varies the height a valve opens in order to improve performance, fuel economy...

James Pickard patented the use of a flywheel and crankshaft to provide rotative motion from an improved Newcomen engine. In 1720, Jacob Leupold described...

A tappet or valve lifter is a valve train component which converts rotational motion into linear motion in activating a valve. It is most commonly found...

Valve float is an adverse condition which can occur at high engine speeds when the poppet valves in an internal combustion engine valvetrain do not properly...

Nissan Variable Valve Event and Lift (commonly abbreviated as VVEL) is an automobile variable valve timing technology developed by Nissan. Nissan VVEL...

valve lifter or hydraulic lash adjuster, is a device for maintaining zero valve clearance in an internal combustion engine. Conventional solid valve lifters...

VTEC (described as Variable Valve Timing & Lift Electronic Control, but stands for Valve Timing Electronically Controlled) is a system developed by Honda...