Fisher 399A - Page 24

Type 399A-161-112
17
Figure 5. Principle of Operation Schematic
PILOT
SUPPL Y
PRESSURE
LINE
TYPE 254E
FILTER
(OPTIONAL)
TYPE 112
VARIABLE
RESTRICTOR
TYPE 161
PILOT CONTROL
SPRING
TYPE 161 PILOT
VALVE PLUG
TYPE 161 PILOT
VALVE PLUG
SPRINGPILOT INLET
PILOT STATIC
CONTROL LINE
AND PILOT\
BLEED
(EXHAUST)
MOTION INDICA TOR
TYPE 399A DIAPHRAGM
SPRING
TYPE 399A
DIAPHRAGM
SUPPORT
TYPE 399A
DIAPHRAGM
INLET PRESSURE
LOADING PRESSURE
OUTLET (CONROL) PRESSURE
PILOT EXHAUST
40B46386-C
30B4382-C
C0797/IL