A valve is used to control flow of liquids and gases. And ball, gate and globe valves are used to control flow of liquids. These valves in all forms are used to create waterways, and it is therefore essential to understand the differences and their uses.
Ball valve made of solid elements offers high durability, and have the ability to function perfectly even after long idle time. It has a sphere made of brass, stainless steel, or chrome plated brass, embedded inside the conduit. On the top of the sphere is a lever attached which can move in a quarter turn only. When the level lies parallel to the pipe, the sphere allows water to flow. When the lever is perpendicular to the pipes the solid sphere blocks the water flow. The water flow is controlled by moving the lever from 0 to 90 degree in terms with the pipe with whom it is attached.
On the flip side though you have the provision to make water flow partially through the pipes by keeping the lever in between 2 limits, but due to water pressure, water pipes might distort.
The advantage of this kind of valves is that you can easily and quickly open or close it. However, water hammers the sphere and the sides of the pipe all the time, except when it is fully open to channelize the water.
Globe valve is wheel based valves which when turned on reduces the flow of water though a pipeline by a set of stationary ring seat in a spherical body. Globe valves contain a spherical area, separated into 2 halves by an opening that forms a seat. On this seat, a plug can be screwed, using the wheel that can control the flow of water or stop it altogether.
It is difficult to understand if a globe valve is open or close, especially if it is partially open. Furthermore, it cannot be operated single handedly, as in the case of ball valve.
Gate valves are used to control the flow of liquid and it is generally operated by turning a wheel and the gate moves up and down. When the wheel is turned to bring the gate down, and it reaches the lowest position, it blocks the flow of water. When the wheel is operated to do the opposite, the gate is in the highest position, and the water can flow without any hindrance.
It is quite easy to realize which position the gate is by looking at the rising stems, which are part of the Gate Valves. If the stems are rising and is visible it means the Gate Valve is open and when the stems are not visible it means the Valve is closed.
Gate Valves stay in contact with the flowing water, and thus is highly susceptible to corrosion and subsequently becomes non-functional and finally breaks. As it is operated slowly the chances of water hammering is negligible. It should be used either in open or closed conditions, if partially kept it might get damaged by water pressure and vibration.
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