Valves Description with animation(Gate valve, Glob Valve, Ball Valve, Butterfly Valve)

Gate valve:
A gate valve, also known as a sluice valve, is a valve which opens by lifting a round or rectangular gate/wedge 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, so gate valves are often used when a straight-line flow of fluid and minimum restriction is desired. The gate faces can be parallel, but are most commonly wedge-shaped.

Applications/uses of gate valve:

Gate valves are widely used for all types of applications and are suitable for both above ground and underground installation. Not least for underground installations it is paramount to choose the right type of valve to avoid high replacement costs.

Gate valves are designed for fully open or fully closed service. They are installed in pipelines as isolating valves, and should not be used as control or regulating valves.

Gate valves are often used when minimum pressure loss and a free bore is needed. A gate valve is a multi-turn valve meaning that the operation of the valve is done by means of a threaded stem. As the valve has to turn multiple times to go from open to closed position, the slow operation also prevents water hammer effects.

Gate valves can be used for numerous types of applications, including water supply, gas supply, wastewater treatment and fire protection. AVK's gate valves are suitable under the following working conditions:

Globe valve:

A globe valve, different from ball valve, is a type of valve used for regulating flow in a pipeline, consisting of a movable disk-type element and a stationary ring seat in a generally spherical body.

Globe valves are named for their spherical body shape with the two halves of the body being separated by an internal baffle. This has an opening that forms a seat onto which a movable plug can be screwed in to close (or shut) the valve. The plug is also called a disc or disk. In globe valves, the plug is connected to a stem which is operated by screw action using a hand wheel in manual valves. Typically, automated globe valves use smooth stems rather than threaded and are opened and closed by an actuator assembly.

 

Applications/uses of globe valve:

The following are some of the typical applications of globe valves:

v  Cooling water systems where flow needs to be regulated

v  Fuel oil system where flow is regulated and leak tightness is of importance.

v  High-point vents and low-point drains when leak tightness and safety are major considerations.

v  Feed water, chemical feed, condenser air extraction, and extraction drain systems.

v  Boiler vents and drains, main steam vents and drains, and heater drains.

v  Turbine seals and drains.

v  Turbine lube oil system and others.

Ball valve:

A ball valve is a form of quarter-turn valve which uses a hollow, perforated and pivoting ball to control flow through it. It is open when the ball's hole is in line with the flow and closed when it is pivoted 90-degrees by the valve handle. The handle lies flat in alignment with the flow when open, and is perpendicular to it when closed, making for easy visual confirmation of the valve's status.

Ball valves are durable, performing well after many cycles, and reliable, closing securely even after long periods of disuse.

Typical Applications of Ball Valves:

The following are some typical applications of ball valves:

v  Air, gaseous, and liquid applications requiring bubble-tight service

v  Low-point drains and high-point vents in liquid, gaseous, and other fluid services

v  Instrument root valves

v  Cooling water and feed water systems

v  Steam service

Butterfly valve:

A Butterfly valve is a quarter-turn rotational motion valve, that is used to stop, regulate, and start flow.

Butterfly valves are easy and fast to open. A 90° rotation of the handle provides a complete closure or opening of the valve. Large Butterfly valves are usually equipped with a so-called gearbox, where the hand wheel by gears is connected to the stem. This simplifies the operation of the valve, but at the expense of speed.

Applications/uses of butterfly valve:

Butterfly valves are used on ships, firefighting apparatus and domestic piping. On ships they are used for large capacity lines, such as forward and aft sea water suction lines. Butterfly valves can also be used across a wide range of other applications, performing particularly well in large volume water applications and slurry applications.

The following are some typical applications of Butterfly valves:

Cooling water, air, gases, fire protection.

Slurry and similar services.

Vacuum service.

High-pressure and high-temperature water and steam services.

Compressed air or gas applications.

Full description of all valves: