Control valves is a collective name for the type of valves used to regulate flow and pressure in a process. The controllable variation in flow is achieved by varying the size of the flow passage in the valve. The direct control of flow rate enables control of process parameters such as pressure, temperature, and liquid level.
How control valves work
Control valves are usually opened and closed using electric, hydraulic, or pneumatic actuators. The valve position is determined by an input signal, typically 4–20 mA, where 4 mA corresponds to a closed valve and 20 mA corresponds to a fully open valve.
Any value between 4 to 20 mA is corresponding to a mechanical position, degrees for rotary valves and lift in mm for linear valves. In most cases a positioner with an internal control loop is used i.e. the mechanical position is continuously sensed and compared to the input set value, allowing the positioner to set the lift angle.
Which control valve will fit your application?
All types of commercially available industrial control valves are designed for their specific application, depending on, for example, media type, temperature range, pressure range and flow range. For simpler applications, traditional shut-off valves such as butterfly valves and ball valves are suitable. For more demanding applications where there is a risk of erosion, cavitation and loud noises, a ball sector valve is preferred.
There are no control valves that are suitable for all applications – so consult a specialist for advice on which type of control valve, actuator and positioner will provide the lowest total life cycle cost in your process.
Sizing and selection
Get help with the dimensioning and calculation of control valves with our Ramén PRO Sizing calculation tool. Here you can find the control valve that best suits your process by entering your unique parameters. The software then suggests the best option for your application. Our experts at Ramén Valves are available to help with control valve calculations if you need it. You can book an appointment with us to get help. With our support, you can ensure that your control valves are correctly dimensioned.
Our control valves
Ramén Valves offers a wide range of control valves of the type; Ball Sector Valves, Eccentric Rotary Plug Valves, Microflow Globe Valves, and globe style control valves.
Ball Sector Valves
Our in-house manufactured Ramén Ball Sector Valve consists of a ball sector with an elliptical to circular opening, which provides high resolution and equal percentage control characteristics in the most demanding control applications. Ramén Ball Sector Valve has been designed as a control valve for liquids, gases, steam, media abrasive particles, sludge, abrasive slurry, powder, pellets, and viscous media. The design is well proven in a variety of process industries since the 1950s. This type of valve can also be called a segment valve. Read more about our ball sector valves.
Eccentric Rotary Plug Valves
Eccentric rotary plug valves use a cam like motion to move the plug into the seat, thereby effecting closure. There are several advantages to this type of valve. There is less torque on the plug once it breaks free of the seat as it is no longer in contact with the seat. Since there is no contact between plug and seat, eccentric rotary plug valves will not exhibit the wear normally seen with a ball valve, whose plug is in constant contact with the seat during operation. Ramén Valves offers eccentric rotary plug valves from the American manufacturer Cashco Inc. Read more about our eccentric rotary plug valves.
Microflow globe valves
Microflow globe valves are small control valves designed for pilot plant and research applications. They are suitable for control of low flow applications in all types of process industries. Per definition in EN60534, microflow valves are valves with a Cv > 0,05. Ramén Valves supply a wide range of microflow valves from the American brand Badger Meter. Learn more about our microflow globe valves.
Globe style control valves
Globe style control valves are the most common type of control valve. They got their name because in the early design of the valve the interior cavity of the valve had a circular or globe shape. Globe valves are also known as Linear Valves because the stem that actuates the valve moves up and down in a straight line. Learn more about our globe style control valves.