Product Description
WM318-G – RATIO RELAY VALVE (112201)
PART NUMBER(S):
Fleet Products: WM318-G | OE: 112201, WM-318-A, WM318A | Automann: WM318AX
DESCRIPTION:
Model: WM318 Ratio Relay Valve
Vehicles: Tractor-trailer brake system configurations
• Valve Type: Three-way, compensating, pilot pressure-operated relay valve
• Ports: (3) 1/4" NPT
• Adjustable Ratio: Output to input pressure from 1.3:1 down to 0.8:1
• Cracking Pressure: 1.5 psi with 100 psi supply
• Max Operating Pressure: 150 psi
• Operating Temperature: -20°F to 200°F
• Material: Industrial-grade alloy body, air brake system rated
• Compliance: Meets requirements for tractor protection valve applications
Applications:
Used in air brake systems to modulate brake pressure between tractor and trailer. This ratio relay valve provides output pressure in proportion to pilot pressure, protecting system integrity by preventing downstream air loss through open service lines. The adjustable pressure ratio ensures proper balance between tractor and trailer braking. Commonly installed as a tractor protection valve or balancing relay in heavy-duty fleets.
CROSS-REFERENCE(S):
112201, AC025, WM-318-A, A12502035, U27WM318A, WIL 112201, 112201X, TURA12502035, WM318AX, TURA12502-035, WM318A, A12502-035, WIMWM318A, 3945114, AC295, 112201, 112201X, 3945114, A12502-035, A12502035, AC025, AC295, TURA12502-035, TURA12502035, U27WM318A, WIL 112201, WIMWM318A, WM-318-A, WM318A, WM318AX, wm318-g, 112201,
A cross-reference listing means this part may be a compatible replacement for these part numbers based on OEM or distributor data.
IMPORTANT INSTALLATION NOTES:
✔ Ratio is field-adjustable; verify required output/input ratio before installation
✔ Install with all (3) 1/4" NPT ports properly connected and leak-checked
✔ Use as a ratio relay or tractor protection valve only in approved systems
✔ Ensure mounting orientation allows proper air flow and shuttle function
✔ Do not exceed 150 PSI max system pressure
SOLD AS NEW
Brand new and ready to install, with OEM Grade Reliability
SUPPORT & ORDERING
For technical support, installation guidance, or to confirm fitment, Call: 1-877-243-0442 | Email: sales@fleet-products.com
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