Schneider Electric (Barber Colman) AT-532-222-1-02 Restrictor Tee

The Schneider Electric (Barber Colman) AT-532-222-1-02 Restrictor Tee is an essential component for precisely managing pneumatic control system airflow. Designed with a fixed .0075" orifice, this restrictor ensures the correct volume of air is supplied to the branch line, allowing one-pipe thermostats and transmitters to regulate pressure effectively via bleed action. Without a properly sized inline restrictor, bleed-type controllers cannot vent sufficient air to modulate branch pressure, often leading to valves slamming or failing to open.

Engineered for 1/4" barbed tubing connections, the AT-532-222-1-02 is the direct performance replacement for discontinued models AT-532-222-1-0-1 and AT-532-222-1-01. Its durable construction is built to withstand standard HVACR operating pressures, maintaining consistent backpressure for stability in heating and cooling sequences. This part is a staple for technicians troubleshooting unstable pneumatic branches or calibrating legacy Barber Colman pneumatic fittings to ensure smooth, modulated control of dampers and valves.

Key Benefits

• Precise Flow Control: The calibrated .0075" orifice provides a fixed 1.0 SCFH flow rate, critical for the accuracy of pneumatic HVAC controls.
• Universal Compatibility: Features standard 1/4" barbed connections for seamless integration with polyethylene or polyurethane pneumatic tubing.
• Direct Replacement Logic: Serves as the updated field replacement for legacy AT-532-222-1-01 units, ensuring system continuity during maintenance.
• System Stability: Prevents "hunting" and erratic valve behavior by establishing the necessary backpressure for one-pipe bleed controllers.

Common Questions

Why is my one-pipe thermostat failing to regulate branch pressure?
Frequently, this occurs because the restrictor tee is missing or clogged. An unrestricted main line provides more air than the thermostat can bleed off, causing the branch pressure to stay at main line levels regardless of setpoint.

Can I use this tee with two-pipe pneumatic thermostats?
Typically, two-pipe thermostats regulate their own supply air and do not require an external inline restrictor. This tee is primarily designed for one-pipe/bleed-style pneumatic circuits.

How do I identify a failing pneumatic restrictor?
Look for signs of oil or moisture contamination from the compressor station. If the .0075" orifice is obstructed, the branch line will lose pressure, failing to actuate controlled devices.

Disclaimer: While we strive for 100% accuracy, product data and specifications are subject to change. Please contact our team to confirm compatibility or technical details before purchasing.