Description
PR-4 style air-brake pressure protection valve (PAI 802634) with 70 psi opening / 65 psi closing pressure and 1/4″-18 NPT inlet and outlet ports. Drop-in aftermarket replacement for the Haldex 90555396 / KN31011 valve used to isolate auxiliary air systems (suspension, accessories) from the primary brake circuit when supply pressure drops.
Specifications
| Manufacturer | PAI Industries |
|---|---|
| Part Number | 802634 |
| Part Type | Pressure Protection Valve (PR-4 style) |
| Opening Pressure | 70 psi |
| Closing Pressure | 65 psi |
| Inlet Port | 1/4″-18 NPT |
| Outlet Port | 1/4″-18 NPT |
| Body Color | Black |
Cross References
This valve replaces or is equivalent to the following part numbers:
- Haldex: 90555396, KN31011
- Navistar: 2585470, 2586470C91, 356596, 356596C91
- Sealco: 140270
Applications
Heavy-duty truck and bus air systems where a pressure-protection valve is required to keep auxiliary circuits from drawing the brake reservoirs below the cut-out pressure. Common installations include:
- Mack and International medium- and heavy-duty trucks (auxiliary air supply)
- Air-suspension supply lines on tractor and trailer applications
- Accessory-air protection downstream of dryer and primary tanks
Verify the failed valve’s opening pressure (70 psi here) and port size (1/4″-18 NPT) before ordering — PR-4-style valves are also produced in 55 psi and other thread variants.
