Valves
Valves are mechanical devices that help in controlling the pressure and flow within a process or system. They are important components of the piping system that helps in conveying vapors, gas, liquids etc.
Valve and its types
This article will help you provide a good understanding between the types of valves. Different types of valves include gate, globe, butterfly, plug, check, diaphragm, control, pinch valves etc. each type of valve has model numbers with different functional capabilities and features. Some of the valves are self-operated or they are operated with hydraulic, pneumatic or actuator.
10 types of valves
The 10 types of valves are as follows:
1. Globe valves
Globe valves are operated by reciprocating the action of plug or disc. The plug or disc moves to or away from the seat by stopping the flow of fluid. The plug or disc seats over the valve seat and the valve seat is removable. These valves are manually operated and it is available from 12mm to 300mm in size.
2. Gate valves
Gate valves are used for shutting off operations. They have a rising and non-rising stem. Gate valves are available in many sizes ranging from 12 mm to 30 mm and more. They are light in weight and it offers low pressure drop. Materials for gate valve construction are carbon steel, cast iron, bronze, nickel alloys etc.
3. Ball valve
Ball valves are made up of spherical plug as it is the controlling element. They are used in chemical industries where shut off and throttling is required. Ball valves are compact and it requires low maintenance. Available in sizes from 6 mm to 900 mm.
4. Butterfly valves
Butterfly valve controlling element is a disc that is called blade, flapper or van. It rotated in horizontal and in vertical directions. It is suitable for throttling at low pressure and it is easy to install. It can be screw type or wafer type. Its size varies from 50 mm to 900 mm.
5. Diaphragm valve
Main parts of the diaphragm valve are the bonnet, body and flexible diaphragm. Diaphragm valves are classified as weir type and straight through type. In weir type diaphragm valves are of low thrust and shut off stroke is needed. The other straight through type diaphragm is suitable for handling slurries and other suspensions. It is available in 3 mm to 600 mm sizes.
6. Plug valves
Plug valves are used for on and off services. The main part of the valves are plug, body and cover. The plug has a slit cut in it and it allows the flow of fluid. Plug valves can be lubricant and non-lubricant types.
7. Needle valve
Needle valve contains the plug. It is tapered and sits very accurately into the seat. The size varies from 3 mm to 25 mm. It is used for controlling hydraulic fluid and air and reduces pressure fluctuations.
8. Angle valve
These are very similar to globe valves. Angle valves give lower pressure drops and less pipe fittings. These are used for corrosive fluids. It contains a single and split body.
9. Y-type valve
In this valve the orifice is at 42 to the path flow. It offers good throttling conditions and low pressure drop.
10. Control valve
Control valves are used for controlling level, temperature, flow rate and pressure etc. the selection of these valves are dependent on its process condition as well as requirement.
