MADE IN U.S.A SINCE 1939

Service Relay Valves
(4 Delivery Ports w/ Ratio Feature)

  • The ratio feature is considered a benefit in hard stop situations & refers to the relationship between the control air pressure to the valve & the delivered air pressure from the valve to the service brake chambers.
  • During normal stopping a 1:1 ratio exists between the control & delivered air pressures.  In a hard stop the ratio   momentarily changes to 1:1.5 until valve lap off occurs & the 1:1 ratio is restored.  This change takes place in less than 1/100 of a second.
  • Do not use ratio feature valves on converter dollies, trailer turntable axles or lift axles.
  • Dimensions: Height 4.75” – Width 4.72” – Depth 5.63” – Approximate Weight: 3.92 lbs.
  • PLUG UNIT ASSEMBLIES 110143 & 110583
  • MINOR REPAIR KIT 110005 
  • MAJOR REPAIR KIT 110118 
  • AUXILIARY SUPPLY PORT REPAIR KIT 110673
  • Mounting Hardware – See Air Valves & Related Products / Mounting Hardware
  • Air Piping Diagrams – See Technical / Air Piping Diagrams, multiple diagrams are applicable.