Control Valve Manufacturer in India

A control valve regulates fluid flow by continuously adjusting the flow passage in response to process requirements, helping control parameters such as flow, pressure, temperature and liquid level. Speciality Valve offers control valves along with appropriate valve bodies, trims, actuators, and control accessories. Each configuration is selected according to the process medium, flow conditions, pressure, temperature and valve size. Actuator arrangement, trim material and required flow characteristics are also considered.

Control Valve Types and Actuation:

Speciality Valve offers control valve configurations with electric and pneumatic actuation. Actuator selection depends on the available power source, required response, control system and fail-position requirements.

Electric Control Valve:

Electric control valves use a motor-driven actuator to position the valve according to the specified control command.

• Modulating control, with on-off operation available where required by the application.

• 4–20 mA or specified control signals

• PLC and DCS integration

• Position feedback

• Local or remote operation

• Fail-position arrangements where specified

• Limit switches and actuator accessories

Pneumatic Control Valve:

Pneumatic control valves use compressed instrument air with diaphragm or piston actuators for process regulation.

• Spring-return or double-acting operation

• Air-to-open or air-to-close action

• Fail-open or fail-close configuration

• Electro-pneumatic positioners

• Solenoid valves

• Air-filter regulators

• Limit switches and position transmitters

Electric vs Pneumatic Control Valve Selection:

Control Valve Technical Specifications:

Specifications vary according to valve design, actuator and service conditions.

Control Valve Sizing:

Valve sizing is based on the actual process operating conditions rather than pipeline size alone.

• Flow Requirements: Minimum, normal and maximum flow conditions used for valve sizing and required control range.

• Differential Pressure: Pressure available across the valve

• Inlet and Outlet Pressure: Upstream and downstream operating pressures

• Temperature: Operating and design temperature

• Fluid Properties: Density, viscosity, vapour pressure and other relevant properties

• Valve Size: Selected according to capacity, velocity and piping requirements

• Liquid Service: Cavitation and flashing evaluated where applicable

• Gas and Steam: Velocity, pressure drop and noise considered during sizing

Cv or Kv should be established for the specific valve, trim and operating conditions rather than treated as a fixed value for the entire range.

Flow Characteristics:

• Linear: Provides an approximately proportional change between valve travel and flow capacity under defined conditions.

• Equal Percentage: Provides progressively larger changes in flow capacity as valve travel increases.

• Quick Opening: Produces a relatively large increase in flow during the initial valve travel and is generally selected where a large initial increase in flow is required rather than precise modulation across the full valve travel.

Pressure Drop:

Pressure drop is considered during valve sizing to provide adequate control while avoiding excessive velocity and unstable operation.

• Cavitation: Evaluated for liquid services where pressure can fall below vapour pressure.

• Flashing: Considered where liquid changes to vapour after pressure reduction.

• Flow Velocity: Controlled to reduce excessive erosion and wear.

• Noise: Evaluated for high-pressure gas and steam applications.

• Trim Wear: Excessive pressure drop can increase velocity and accelerate erosion.

• Control Stability: The available pressure drop across the valve should support stable modulation across the required operating range.

Seat and Trim Options:

• Metal Seat: Used for demanding pressure and temperature conditions.

• Soft Seat: Selected for compatible services requiring tighter shut-off.

• Stainless Steel Trim: Used for compatible process media where corrosion resistance and service conditions support its selection.

• Hardened Trim: Applied where erosion and wear resistance are required.

• Stellite Hard-Facing: Provided for selected severe-service applications.

• Anti-Cavitation Trim: Used for selected high-differential-pressure liquid services.

• Low-Noise Trim: Applied where gas or steam velocity can generate excessive noise.

Where Are Control Valves Used?

• Separator and Vessel Level Control: Maintaining liquid level by regulating inlet or outlet flow.

• Pipeline Pressure Control: Modulating flow to maintain upstream or downstream pressure at the required setpoint.

• Steam Header Regulation: Controlling steam flow and pressure to process equipment and distribution headers.

• Boiler Feedwater Control: Adjusting feedwater flow according to boiler drum level and steam demand.

• Fuel Gas Regulation: Controlling gas flow to burners, heaters and process furnaces.

• Cooling Water Control: Modulating cooling-water flow to heat exchangers and process equipment.

Testing and Documentation:

Inspection, testing and documentation can be provided according to the agreed project and order requirements.

• Shell and seat pressure testing

• Valve travel verification

• Actuator functional testing

• Positioner calibration

• Limit-switch verification

• Material certificates

• Technical datasheets

• General arrangement drawings

• Inspection and testing documentation

Share your process conditions, required Cv/Kv, pressure rating, control signal and fail-action requirements with Speciality Valve for valve selection and quotation.