Valves are mechanical devices that control the flow and pressure within a system or process. They are essential components in the industry and there are many types of valves available to accommodate a wide range of applications.
Regardless of type, all valves have the following basic parts: the body, bonnet, trim (internal elements), actuator, and packing.
Exist a huge range of valves and each type has a number of models with different features and capabilities. It could be done multitude of classifications but the two most commonly used are based on functions and mechanical motion. It should bear in mind that most valves fall into one or more classifications.
Classification by function
- Stop (Isolation) valves
These valves are used to stop the flow or isolate a portion of the system until it is desirable to achieve flow downstream of the valve.
- Regulating valves
This group is used in piping systems to regulate the flow of fluid. The flow regulation is accomplished by increasing or decreasing the flow through the valve in response to a signal form a pressure, flow or temperature control.
- Backflow prevention valves
Generally, checks valves (non-return valves) are used for the prevention of backflow in piping systems. The valves are mostly self-actuating, in this way, the valve’s disk is kept open by the forward flow of fluid and quickly closed by reverse.
- Pressure relief valves
These valves are used to protect piping and equipment form being subjected to pressures that exceed their design pressures. Safety valves and relief valves primarily serve this requirement.
Classification by mechanical motion
- Linear motion valves
This kind of valves uses a closure member that moves in a straight line to start, stop or throttle the flow.
- Rotary motion valves
A disc or ellipse (obturator) rotate about an angular or circular shaft extending across the diameter of an orifice.
- Quarter turn valves
rotatory motion valves which requires approximately a quarter turn motion of the stem to go to fully open from a fully closed position and reverse.
Gestion de Compras has a large experience on manufacture of steel valves, stainless steel valves, copper and brass valves, casting valves… such as butterfly valves, WAFER valves, safety valves, plug valves, check valves, globe valves, ball valves, diaphragm valves, needle valves, gate valves, pressure relief valves, balance valves, control valves, multifunctional valves, non-return valves, ...