Pneumatic Controls

Surplus City Liquidators sources surplus pneumatic pressure HVAC controls directly from manufacturers as overstock. These are brand-new commercial building pneumatic controls from overproduction runs, discontinued model lots, or excess inventory buyouts. "Surplus" refers to how the inventory was acquired, not the condition of the part; components arrive in the same new state as they would from a traditional controls distributor, not pulled from decommissioned buildings. Items ship in manufacturer packaging where available, which matters for calibrated pneumatic components.

The collection covers the core components of a pneumatic control loop: pneumatic room thermostats (direct acting and reverse acting, 1-pipe and 2-pipe configurations, temperature ranges from approximately 45 to 90°F), pneumatic temperature transmitters, pneumatic selector switches, and pneumatic receiver gauges. On the actuation side, the collection includes pneumatic damper actuators, including unit ventilator actuators with spring ranges such as 5 to 12 PSI, along with pneumatic VAV control boxes and pneumatic control conversion kits. Supporting service needs, pneumatic calibration kits and retrostat kits for room thermostat replacement are also stocked. Brands confirmed in inventory include Honeywell, Carrier, Barber-Coleman, Johnson Controls, and Ingersoll-Rand.

For any direct/reverse acting pneumatic thermostat replacement, the key match points are acting direction, pipe configuration (1-pipe or 2-pipe), temperature setpoint range (such as 45 to 85°F or 60 to 90°F), throttling range, and air supply pressure requirement. Day/night, diffuser-mounted, and single-setpoint versus adjustable configurations represent additional variables, so confirm which type the existing system uses before ordering. For pneumatic HVAC thermostat replacement using a retrostat kit, the adaptor base accommodates a range of legacy wall plate configurations, enabling substitution across multiple OEM brands with a single compatible unit.

Yes, in most cases. Pneumatic controls use a standard compressed air signal, typically 3 to 15 PSI for most building control applications, that is not proprietary to any single manufacturer, making cross-brand substitution feasible when the key specifications match. Acting direction, PSI range, pipe configuration, and temperature or pressure range are more important than brand name for most pneumatic thermostats, transmitters, and selector switches. For actuators, spring range, stroke, and maximum safe pressure are the critical variables; the PSI-based spring range must match the system's control signal range rather than the original brand designation.

For any surplus pneumatic actuator HVAC selection, the essential specifications for a damper actuator are spring range (the PSI range over which the actuator travels its full stroke), maximum safe operating pressure, stroke length, and mounting configuration. Unit ventilator damper actuators, such as the Honeywell MP516A series with a 5 to 12 PSI spring range, are application-specific; verify the unit model and actuator mounting before ordering. For pneumatic valve actuators, add stem travel and valve port size to the matching criteria; two-stage models with independent start pressures require confirmation that the staging matches the control sequence in the existing system.

Yes. A pneumatic calibration kit HVAC is an important service tool for any pneumatic controls maintenance program, and kits are available in this collection. A standard kit typically includes two 0 to 30 PSI gauges, a pressure bulb with tubing and fitting for applying test pressure, a thermostat positive key, a gauge adjuster, a calibration screwdriver and wrench, and a tool pouch with a carrying case. Confirm the specific contents of the listed kit before ordering, as configurations vary. Calibration kits are cross-brand and work with pneumatic thermostats, transmitters, and controllers from Honeywell, Johnson Controls, Barber-Coleman, and similar legacy pneumatic control systems.

Most pneumatic controls, including thermostats, transmitters, selector switches, calibration kits, and small actuators, are compact components that ship via standard ground to all 48 contiguous states. Larger items such as VAV control boxes may require freight shipping based on size and weight; freight charges are calculated separately and confirmed by Surplus City's team after the order is placed. Check online for pickup availability at our various locations.