• Aftermarket valve replaces Sealco relay emergency valve
• Ratio Feature
• Do not use this valve on converter dollies, trailer turntable axles or lift axles
• 4 Delivery ports
• Supply port = 3/8" pipe thread
• Control port size = 3/8" pipe thread
• Reservoir port size = 3/4" pipe thread
• Delivery port size = 3/8" pipe thread
• Nominal crack pressure = 4.5 psi
  

The Ratio Feature is considered a benefit in hard stop situations and refers to the relationship between the control air pressure to the valve and the delivered air pressure from the valve to the service brake chambers. During normal stopping, a 1:1 ratio exists between the control and delivered air pressures. In a hard stop, the ratio momentarily changes to 1:1.5 until valve lap-off occurs and the ratio is restored. This change takes place in less than 1/100th of a second.

Cross References: 229434, 277446, 110200, RE045, REO45
A cross reference listing means that this valve is a suitable replacement for the part numbers listed. Some changes in air line plumbing may be required.