A valve assembly includes a housing with a bore, a supply port in fluid communication with the bore, a control port in fluid communication with the bore, and a vent port in fluid communication with bore such that the vent port is located at a location of the housing that is between the supply port and the control port. A valve seat assembly with a valve seat body is disposed within the housing and defines a control chamber in constant fluid communication with the control port, a vent path from the control port to the vent port, and a supply passage which provides constant fluid communication from the supply port to the control chamber. A vent valve member is selectively seated and unseated with the vent valve seat to selectively prevent and permit fluid communication from the control port to the vent port respectively.