Valves: INTRODUCTION AND WHY SO MANY TYPES?
Living in this modern age we often fail to see the complexity that makes our daily life easy. A green lush followed by concrete jungle connected by long stretches of asphalt, countless varieties of delicacies in the fancy food stores made of glass to huge structures housing all the things we need. The fuel we use to drive our economy to medicine that helps us overcome the tough times. But we aren’t here to read a literature on our everyday lives, are we? We are here to know about one of the things that make it possible!
Valves are everywhere, from the beginning of civilization to the time that we live today and beyond. Valves perform multiple tasks such as starting and stopping of flow along with pressure regulation, prevention of back flow, flow regulation and diversion of things in question. Here is a general classification of valves based on the uses, types and how they help transform our lives.
Ball valves uses a hollow pivoting ball encased in its housing to control the flow. When turned 90 degrees by the handle, the hole in the ball is aligned to the flow and is in “open” position and to stop the flow, simply turn the handle perpendicular to the flow. Ball valves falls under quarter-turn type and are popular due to ease of operation, repair and versatility in Industries and residencies.
A butterfly valve uses a disc to start, stop and regulate the flow. It is also a quarter-turn valve and is mostly mated with Pneumatic or electrical actuator for smoother operation. It is light in weight and can perform better throttling or control of the fluid. They vary in design for different application and parameters like temperature, pressure etc.
Gate valves uses a gate or barrier against the flow to open or close it. Also referred to as sluice valve, the gate is normally wedge shaped for better sealing. Once the gate is out of the way, there is practically no flow resistance. The flow rate is not corresponding to how much the gate is opened and it causes uneven flow and vibrations in the gate damaging the seal and seats. Hence the gate valves are only used for open and shut-off functions.
Globe valves have a plug connected to a stem which moves perpendicular to obstruct the flow. The plug sits on the seat for a closed position while it moves away to regulate the flow or completely shut-off. They have good shut-off and throttling capabilities and are easy to maintain.
Diaphragm valves has an elastomeric diaphragm and a saddle or seat on which the diaphragm closes the valve. The full-bore or straight through design are used for on-off application while weir type is used for throttling purposes. They are mostly actuated by compressed air but they can be manual, electric or hydraulic too. These valves perform well for dense and hard material flow.
These type of valves are of full-port or full-bore type. A pinching effect is used to obstruct the flow and they are excellent for slurries and process with solids as the flexible rubber sleeves collapses on themselves creating a good seal. There is less risk of contamination as the internals of valves are not exposed to the media and it helps in isolation. They are used in food, beverages, medical and chemical industries etc.
These valves generally are used for regulation or shut the air flow in ducts. It can be used to direct the airflow or maintain a set temperature for heating or cooling applications (HVAC). They are mostly electrically actuated for the required degree of opening for active regulation in conjunction with thermostat or for exhaust ducts.
Ultimately, the deeper we delve into this, the more we’ll learn about valves. They hold a critical role in our lives and that’s why we do intensive research and development in design and engineering of valves to get one step closer to a much safer and brighter tomorrow. The same goes to the technologies that help automate these valves giving you a better control.
At Cair Euromatic Automation we actuate with accuracy. Explore our range of Electrical Actuators and Motorized valves along with a wide range of new products. See you next time!