Valves are mechanical devices that controls the flow and pressure inside of a system or process. They are essential elements of a piping system that conveys liquids, gases, vapors, slurries etc..
Different kinds of valves are offered: gate, globe, plug, ball, butterfly, check, diaphragm, pinch, pressure relief, control valves check here etc. Each of these types incorporates a number of models, each with various features and functional capabilities. Some valves are self-operated while some manually or with the actuator or pneumatic or hydraulic is operated.
Gate valves are typically less expensive than ball valves, but you are more susceptible to corrosion. Over time, the interior stem that connects the knob towards the gate becomes increasingly prone to fail. They are often used in combination with larger pipe diameters of two inches or longer. Ball valves are better at forming a strict seal and possess more reliability and longevity than gate valves, but usually are more expensive. They are often employed for shutoff and control applications.
Because ball valves can go in and out immediately, they can be more likely than gate valves to cause water hammer. When a valve is quickly closed on water moving at high-pressure through pipes, it may cause shock waves throughout the plumbing that creates a hammering sound. Under high enough pressure, water hammer could potentially cause a pipe to weaken and break. For that reason, users are encouraged to turn the ball valve lever slowly in order to avoid water hammer.
Rising stems are fixed towards the gate and so they rise reduce together because the valve is operated, providing a visual indication from the valve position and making it possible to grease the stem. A nut rotates across the threaded stem and moves it. This type is merely suitable for above-ground installation.
Non-rising stems are threaded into your gate, and rotate together with the wedge rising and lowering in the valve. They use up less vertical space because the stem is kept inside the valve body. AVK offers gate valves with a factory-mounted indicator for the upper end in the stem to point out the valve position. Gate valves with non-rising stems are ideal for both above-ground and underground installations view more .The majority of AVK’s range are intended with non-rising stem, but we also offer gate valves with rising stem for water, wastewater and fire protection applications.