Control Valves
A Control Valve controls fluid flow by altering the size of the flow passage from a controller, altering the flow rate and the process quantities such as pressure, temperature, and liquid level. Amongst those available at Curtiss Wright are;
- Feedwater Control Valves for industrial applications,
- 3-Way-Valve with encapsulated super-long bellows and emergency gland or with stuffing box seal
- Oxygen control valves with a straight pattern body suitable for use in steelworks and piping
View our full range of Control Valves:
Control Valves: Purpose & Functionality
A Control Valve alters the flow rate by changing the size of the flow passage from a controller influencing quantities of gas or liquid to having an impact on pressure, temperature, and liquid level.
Depending on the type of valve chosen, the limiting mechanism is moved by an electrical, mechanical, pneumatic, or hydraulic actuator. The valve regulates the flow of movement through a valve plug. The plug is attached to a valve stem, which is connected to the actuator.
Typical Control Valve Usage
Processing plants consist of hundreds of control loops that are networked together in order to produce a certain product. Each loop is designed to control certain variables such as pressure, temperature, flow or level within a required range.
However, each loop receives and internally creates disturbances, affecting the process variable and interaction from other loops within the network, which can have a cumulative effect when multiple loops are connected. In an effort to reduce the disturbances, sensors and transmitters are used to collect information. Controllers then process the information and decide the best way to get the process variable back to where it should be.
Once all of the calculating, comparing and measuring has taken place, a type of control element must then implement the strategy which has been selected by the controller, using the valves to alter pressure within the system, compensating for any noise or disturbances and allowing the system to return to a desired state of pressure, flow or temperature.
Examples Of Control Valves Available
Feedwater Control Valves - Industrial applications for high pressure and temperature service environments such as Power Plants and Petrochemical Plants:
Related Products:
3-Way-Valve - With encapsulated super-long bellows and emergency gland or with stuffing box seal - Suitable for toxic or flammable gases and liquids.
Related Products:
Oxygen Control Valves - with a straight pattern body- Suitable for steelworks and piping.
Related Products:
Control Valves: Applications
The use of control valves in power plants
A power plant uses hundreds of valves to control every aspect of its operation. The control valves are critical for optimizing the power plants efficiency can often be exposed to high temperatures and abrasive chemicals.
With the ever-increasing demand for sourcing renewable power and curbing carbon emissions, producing high quality manufactured valves is more important than ever.
Curtiss-Wright have developed innovative control valves that can withstand high environmental demands while remaining cost-effective. Our valves can support throttle accurately, increasing performance for critical power plant operations.
Control valves in petrochemical plants
The petroleum industry is best known for its global exploration and extraction of oil. However, it’s applications are not just limited to oil or gas. Petrochemical plants also manufacture plastics, dyes, food additives and other petrochemicals that derive from natural gas, coal or oil.
Due to the extreme temperatures and pressures needed to produces the materials, high-quality engineering is essential to the operation of petrochemical plants.
Control valves are critical to the performance of the system. Chemicals used in this industry can be hazardous to the surrounding environment and people, making system regulation essential.
Control Valve Advantages
- Rapid and effective functioning
- Absolutely reliable
- Durable service life
- The design is compact to facilitate minimal space consumption
- Minimal pressure drop
Control Valve Disadvantages
- Opening and closing is not prompt
- A large space is required when assembling, starting, and maintaining it
- It is prone to leakage when operated at high temperatures
- The pressure control valve creates vibration.
Control Valve Types
At Curtiss Wright, we offer an extensive range of valves, including:
Butterfly Valves
Changeover Valves
Control Valves
Globe Valves
Gate Valves
Directional Control Valves
Plug Valves
Pressure Relief Valves
FAQ
Manufacturing plants contain numerous control loops, running at the same time and interacting with each other based on instruction from sensors. Control valves play a crucial part in the quality control process.
Process example:
- A controller picks up on any disturbances in the production line.
- The controller creates a strategy to regulate variables back to the required setpoint before the disturbance.
- Control valves are put in place to carry out the strategy set.
- The production line returns back to full working order.
Control valves are available in different types and shapes, and can be classified by their action, number of plugs, and flow characteristics. Control valves based on action are either air to open or air to close. Control valves based on the number of plugs can feature a single-seated valve or double-seated valve, and flow characteristics can be defined in inherent or ideal characteristics or effective/installed characteristics.
Control valves are made up of a number of components, including an actuator, positioner, and valve body.
A control valve is designed to control flow rate, pressure, level or temperature, depending on the desired set point and application. The valve includes a plug or disk, and the position of the plug can be changed by an actuator, to allow fluid or gases through.
Control valves are used in applications including:
- Power plants
- Petrochemical plants
- Railway tankers
Pressure control valves are primarily used in hydraulic systems, assisting in a variety of functions and are designed to monitor and regulate pressure, either manually or electronically.
Types of pressure valves include:
- Relief
- Unloading
- Reducing
- Sequence
- Counterbalance
FURTHER INFORMATION
At Curtiss Wright Valve Division, you’ll find various products suited to an array of industrial markets worldwide, including Power Generation, Oil & Gas, Chemical/Petrochemical, and Defense. Curtiss Wright Valve is an expert manufacturer in control valve manufacturing.
Our range of valves includes Butterfly Valves, Changeover Valves, Check Valves, Control Valves, Directional Control Valves, Engineering Services, Engineering Software, Gate Valves, Globe Valves, Plug Valves, Pressure Relief Valves, Strainers and Instrumentation Equipment.
If you require further information on any product, such as specification sheets, you can find them in the related documents or the library. To locate and contact your nearest sales office, click here. Alternatively, you can fill in a contact form here.