Bench Testing
- Connect manifold gauge set to expansion valve. Connect manifold gauge charge hose to R-134a source. See Fig 1 . Ensure manifold gauge set valves are closed. Put expansion valve bulb in container of water with thermometer.
- Slowly open high-side pressure of manifold gauge set to 70 psi (4.9 kg/cm2 ). Read low-side pressure. Pressure should correspond to bulb temperature as indicated in EXPANSION VALVE PRESSURE table. If pressure values are incorrect, replace expansion valve.
EXPANSION VALVE PRESSURE
| Temperature °F (°C) | Pressure psi (kg/cm2 ) |
|---|---|
| 32 (0) | 20-28 (1.5-2.0) |
| 50 (10) | 32-42 (2.2-2.8) |
| 75 (24) | 62-72 (4.1-4.5) |