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Low/High Temperatures [Classic 21 Series] 2/2, 3/2, & 4/2 Functions, 1/4" to 1-1/2" Port Sizes



  • ¼” to 1 ½” Port Sizes
  • 2, 3 or 4-way valves
  • High Temperature and Low Temperature Applications
  • Readily Adaptable to Vacuum Service
  • Extreme Temperature Range Options including up to 300° F (150° C) for pressure controlled models and down to -40° F (-40° C) with Buna-N Seals

The function of directional control valves is to control the direction of flow in a pneumatic circuit. These valves can regulate the airflow being capable of stopping, passing, and changing the direction of airflow. These three functions usually operate in combination with each other.


Directional control valves have multiple ports with the number dependent on the valve type. All these valves have an inlet and an outlet port while many also have an exhaust port. The 21 series is offered in 2/2, 3/2, and 4/2 valve functions with a port size range of ¼” to 1-1/2” in both NPT and G threads.


The poppet construction of the 21 Series enables high-flow, positive sealing, self-cleaning, and a strong dirt tolerance that delivers a long-life. This valve series is available in both solenoid and air pilot controlled options. Solenoids are offered in several AC and DC voltages.


Fluorocarbon and Buna-N seal options enable these valves to be used in a wide range of lower or higher temperature applications.


Please refer to the link on the left to easily view and download the ROSS Controls 21 Series Inline Poppet Valves with Increased Temperature Range product catalog for additional technical data. In addition, you can filter through all available options below to select the ideal valve that meets your requirements.