Valve timing is the regulation of the points in the combustion cycle, at which the valves are set to open and close. Since the valves require a finite period of time in which to open or close without abruptness, a slight lead-time is always necessary for proper operation. The design of the valve-operating cam provides for the smooth transition from one position to the other, while the cam setting determines the timing of the valve.

In a typical four-stroke engine, the inlet valve is set to open before TDC (top dead centre), towards the end o ....etc

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INTRODUCTION
Ball valves are most widely used valves for flow control in fluid flow lines for wide range of temperature changes (-200°C to 500°C).Most of the outlet valves of chemical plant storage were installed with ball valves for sudden closing and opening purposes. For petroleum and chemical plants it is very convenient to operate with ball valves.
Ball valves are used in situations where tight shut-off is required. The type of seat can vary with the valve pressure rating and m ....etc

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A ball valve (like the butterfly valve, one of a family of valves called quarter turn valves) is a valve that opens by turning a handle attached to a ball inside the valve. The ball has a hole, or port, through the middle so that when the port is in line with both ends of the valve, flow will occur. When the valve is closed, the hole is perpendicular to the ends of the valve, and flow is blocked. The handle position lets you 'see' the valve's position.

Ball valves are durable and usually work to achieve perfect shutoff even after years of di ....etc

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A ball valve (like the butterfly valve, one of a family of valves called quarter turn valves) is a valve that opens by turning a handle attached to a ball inside the valve. The ball has a hole, or port, through the middle so that when the port is in line with both ends of the valve, flow will occur. When the valve is closed, the hole is perpendicular to the ends of the valve, and flow is blocked. The handle position lets you 'see' the valve's position.

Ball valves are durable and usually work to achieve perfect shutoff even after years of di ....etc

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In a world of ubiquitous presence of electrons can you imagine any other field displacing it? It may seem peculiar, even absurd, but with the advent of spintronics it is turning into reality.

In our conventional electronic devices we use semi conducting materials for logical operation and magnetic materials for storage, but spintronics uses magnetic materials for both purposes. These spintronic devices are more versatile and faster than the present one. One such device is spin valve transistor.

Spin valve transistor is different from conv ....etc

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A Butterfly valve is a type of flow control device, used to make a fluid start or stop flowing through a section of pipe. The valve is similar in operation to a ball valve. A flat circular plate is positioned in the center of the pipe. The plate has a rod through it connected to a handle on the outside of the valve. Rotating the handle turns the plate either parallel or perpendicular to the flow of water, shutting off the flow. It is a very robust and reliable design. However, unlike the ball valve, the plate does not rotate out of the flow of ....etc

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I would like to have the graph of gas flow Vs Valve opening.

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dimension of short patern ball valve size 2to 6150 class ....etc

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A gate valve is a valve that opens by lifting a round or rectangular gate out of the path of the fluid. The distinct feature of a gate valve is the sealing surfaces between the gate and seats are planar. The gate faces can form a wedge shape or they can be parallel. Gate valves are sometimes used for regulating flow, but many are not suited for that purpose, having been designed to be fully opened or closed. When fully open, the typical gate valve has no obstruction in the flow path, resulting in very low friction loss.


Gate valves are cha ....etc

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The present day requirement for high performance from a medium power engine has resulted in generally higher maximum crank shaft speeds, typically in the region 5500 ? 6000 rpm. This can be explained by recalling the factors governing the power output of an engine since, if neither piston displacement nor mean effective pressure can be further increased. Then the only other way to raise the maximum power is to permit higher crank shaft speeds. For this reason it becomes increasingly more important to avoid erratic operation of valves. As a resu ....etc

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