THREE-WAY NON-OVERRIDE VALVE ^PRODUCT DESCRIPTION ' DESCRIPTION The WM672 series valves are panel-mounted three-way control valves that are actuated manually and by supply pressure. Each unit consists of a manually-actuated three-way valve stacked in series with a pressure-actuated two-way valve. The two-way valve provides a non-override safety feature. OPERATION The WM672 series valves are spring-returned, normally closed valves that require a minimum supply pressure of 45 PSI (310,3 kPa) to hold the open position after manual actuation. Since the pressure-actuated portion of the valve controls the supply and exhaust ports, the supply port remains closed with insufficient supply pressure, and any outlet pressure is released through the exhaust port. When the supply pressure exceeds 45 PSI (310,3 kPa), the supply port opens and the exhaust port closes. The manually-actuated portion of the WM672 valve controls the outlet port; with adequate supply pressure, this part of the valve can be operated to direct pressure to the outlet port. If the supply pressure drops to the 35-45 PSI (241,3-310,3 kPa) range, the supply port closes. Outlet pressure is exhausted and the trailer emergency brakes are applied automatically. The manual control cannot override this automatic safety function. APPLICATION Designed for industrial and vehicular applications, the WM672 series valves are used to deliver pressure to pneumatic systems that must not be operated with less than 45 PSI (310,3 kPa). In air brake systems of tractor-trailer combinations, the WM672 valve controls the application and release of the trailer emergency brakes. If the supply pressure drops below the necessary level, then the WM672 valve applies the trailer emergency brakes automatically. This valve is not recommended for FMVSS-121 trailer applications. TYPICAL INSTALLATION FUNCTIONAL DIAGRAM

PARTS IDENTIFICATION DESCRIPTION QUANTIT NO SUFFIX! D 1 1 1 1 1 1 1 1 1 1 1 1 1 3 1 1 1 1 1 1 1 3 2 1 Service this unit with repair kit number 100160. To replace only the button on the WM672A, order part number 110061. To replace only the button on the WM672D or E, order part number 105374. Other replaceable items are followed by part numbers. * Asterisk designates parts included in repair kit 100160. STEM BODY CENTER BODY END BODY STEM ASSEMBLY DIAPHRAGM PISTON POPPET SPRING POPPET SPRING O-RING SCREW BUTTON O-RING SCREW SCREW SCREW (114989) SCREEN (116456) POPPET DIAPHRAGM SPACER SCREW O-RING...