AN INSIGHT INTO VARIOUS TYPES OF VALVES

 

Introduction:

Valves play an important role in our everyday lives. Wherever fluids move in a pipe, valves are needed to secure their safe and reliable flow. And this happens in most process industries – and even to make products or materials that might surprise you. Millions of valves are working day and night in various industries globally.

Valves as opined by a leading Valve Stockist in Dubai, are mechanical or electro-mechanical devices that are used to control the movement of liquids, gases, powders, etc. through pipes or tubes, or from tanks or other containers. In most instances, valves rely on some form of mechanical barrier—a plate, a ball, a diaphragm, for example—that can be inserted and removed from the flow stream of the material passing by. Some valves are designed as on-off varieties, while others allow very fine control of the passage of media.

Valves generally help secure safety in process plants by regulating and controlling process flows. Sometimes, the stuff that flows is quite hazardous or erosive, so the valves must be very durable and reliable, even in the most demanding conditions.

Regardless, they need to function steadily and efficiently, no matter what the liquid. As you can see, valves have a mission-critical role in the productivity and safety of process plants – from bioproduct mills to gold mines and oil refineries.

Material selection plays an important role in specifying valves to ensure the compatibility of the wetted parts of the valve with the fluid or powder passing through it. Sizing is determined by the pipe or tubing diameter, flow rate, and the width between flanges for pipeline valves being installed as replacements.

Main Types of Valves:

Ball Valves: Ball Valves are quarter-turn valves incorporating ported spheres that swivel in the pipe stream to either block, or allow, flow. Special designs are available which enable a degree of flow regulation. Key specifications as provided by ball valve suppliers include the number of ports, port configuration, port connections, valve size, and the materials that make up the valve body, its seat, seal, and stem packing. Ball valves are used practically anywhere a fluid flow must be shut off, from a compressed-air line to a high-pressure, hydraulic system. Ball valves can provide low head-loss characteristics as the port can exactly match the pipe diameter. Ball valves also tend to seal better than butterfly valves, but they can be costlier to purchase and maintain. Typically, they are actuated with a lever which provides a visual indication of the valve status.

Butterfly Valves: Butterfly Valves are quarter-turn valves which employ centre-mounted circular flaps that swing into, and out of, the flow stream. Key specifications as provided by butterfly valve suppliers include port connection, valve size, and the materials that make up the valve body, its seat, seal, disc, and stem packing. Butterfly valves are used in wastewater plants, power plants, and process plants for shut-off and for regulating and isolating services and are especially popular in very large diameter pipelines. Generally smaller and cheaper than a ball valve of the same capacity, butterfly valves can be difficult to operate against high pressure and flow. They are also more leak-prone than ball valves and subject to higher head losses.

Gate Valves: Gate Valves are used mainly for blocking fluid flow and are less likely to be employed for flow regulation. A gate valve supplier is of the opinion that these valves use a plate-like barrier that can be lowered into the flow stream to stop the flow. Its operation is similar to that of a globe valve except the gate provides less flow restriction than with a globe-valve plug when the valve is in the fully opened position.

Globe Valves: Most Globe Valves Suppliers, commonly have named these valves for their spherically shaped valve bodies that were at one time common, are also named for their use of a globe-shaped disc that constricts flow by closing against a restricting orifice. The disc is opened and closed with a handwheel on manually operated valves and with an actuator and sliding shaft on automatic valves.

Conclusion:

Valves are often deemed as being bubble-tight, a description for valves that will not allow any liquid passage upon closure. Certain designs are more apt to be bubble tight than others, particularly those valves that are intended for on-off service versus those that are used mainly for regulating flow.

This write-up provides a basic understanding of valves and their selection and uses in various environments. Fevisa, a leading Valve Stockist in the upcoming market, has superior functional capability with global standards in supplying.  Moreover, our Europe origin valves are designed to meet various industrial standards in addition to customer requirements. Our Fevisa team of experts has always been ready to help you in the selection of valves.