The RAPCO RA2H3-2 is an FAA-PMA approved pneumatic vacuum regulator used in aircraft vacuum systems to maintain a stable, preset suction level (inHg) for gyro instruments such as attitude indicators and directional gyros.

It works by automatically bleeding excess vacuum air when system suction exceeds the set value, ensuring consistent performance of vacuum-driven instruments regardless of engine RPM or altitude changes. This helps keep gyro instruments stable and accurate during all phases of flight.

The unit is a direct replacement for older Airborne 2H3-2 / Aero Accessories 2H3-2 regulators, and is commonly found in Cessna, Piper, and other general aviation aircraft equipped with vacuum systems.

It includes adjustable regulation (factory preset around ~5 inHg depending on configuration) and uses standard aircraft hose fittings for installation in the vacuum line between pump and instruments.

Key features include:

RAPCO part number: RA2H3-2
FAA-PMA approved vacuum regulator
Maintains constant vacuum pressure for gyro systems
Replaces Airborne 2H3-2 / Aero Accessories equivalents
Adjustable vacuum setting (factory preset ~5 inHg typical)
Hose fittings: 5/8" pump, 1/2" instrument line
Used in attitude indicator, DG, and turn coordinator systems
Stabilizes vacuum fluctuations from engine-driven pumps
Compact pneumatic bleed-type regulator design
Standard GA aircraft vacuum system component