Pneumatic Control Valve

Technical Summary

Nominal Size: ½” to 24”

Pressure Class: Class 150 to Class 1500

Temperature Range: -29°C to 400°C

Design Standards: ANSI/FCI 70-2, ASME B16.34

Face to Face: IEC 60534 / ISA standards

Control Type: Modulating / On-Off

Actuation: Pneumatic Diaphragm / Pneumatic Piston

Air Supply: 3 to 8 bar

Input Signal: 3–15 psi / 4–20 mA with positioner

Construction and Materials

Body and Pressure Retaining Parts

• ASTM A216 WCB
• ASTM A351 CF8M
• ASTM A217 WC6
• ASTM A182 F316

Internal Components

• Plug: Stainless Steel / Hardened Trim
• Seat Ring: Stainless Steel
• Stem: ASTM A182 F6a, ASTM A182 F316

Sealing System

• Packing: Graphite / PTFE
• Gasket: Graphite / Spiral wound

Functional Design

Pneumatic Control Valve regulates flow, pressure, temperature, or liquid level by modulating valve position through a pneumatic actuator. The actuator responds to an air signal directly or through a positioner, converting the control signal into accurate stem movement.

This design offers fast response, stable throttling performance, and suitability for hazardous locations where pneumatic actuation is preferred over electric systems. Pneumatic control valves are widely used in continuous process industries requiring reliable modulation and fail-safe action.

Material and Grade

Standard Materials

Component	Material	Grade	Typical Application
Body	Carbon Steel	ASTM A216 WCB	General process and utility service
Body	Stainless Steel	ASTM A351 CF8M	Corrosive and chemical process media
Body	Alloy Steel	ASTM A217 WC6	High temperature service
Plug	Stainless Steel	ASTM A182 F316	Flow control and trim durability
Stem	Stainless Steel	ASTM A182 F6a / F316	Actuator force transmission and corrosion resistance
Seat Ring	Stainless Steel	ASTM A182 F316	Sealing and flow regulation

Extended Materials (On Request)

• Duplex Stainless Steel (F51) for chloride-rich environments
• Alloy 20 (CN7M) for acidic chemical service
• Hastelloy C276 for aggressive chemical media
• Inconel 625 for high temperature and severe service

Additional Information

Valve Type	Pneumatic Actuated Control Valve
Control Characteristic	Linear / Equal Percentage / Quick Opening
Actuator Type	Pneumatic diaphragm actuator / Pneumatic piston actuator
Fail Safe Option	Fail open / Fail close / Fail in place
Positioner	Electro-pneumatic positioner / Pneumatic positioner
Accessories	Air filter regulator, solenoid valve, limit switch, position transmitter
Mounting	Yoke mounted actuator assembly

End Connections

• Flanged as per ASME B16.5
• Butt weld as per ASME B16.25
• Threaded ends for smaller sizes

Applications

• Oil and gas industry: pressure and flow control in upstream facilities, gas processing units, and pipeline stations
• Pipelines and transmission systems: control of gas flow, pressure reduction, and metering skid regulation
• Mining industry: process flow regulation, slurry service support systems, and utility line control
• Water and wastewater treatment: pressure management, filtration control, and pumping station flow regulation
• Pulp and paper industry: steam control, chemical dosing, and process flow regulation
• Power generation: steam, condensate, and feedwater control in utility and process systems