Type 2500
22
Figure
14. Direct-Acting, Right-Hand-Mounted 2500-249 Series Controller/Transmitter
CD2114–E
BO998–1/IL
allowing full exhaust of the output pressure. This con-
trol action continues until a sensor level change moves
the flapper away from the plunger, permitting the
Bourdon tube valve to close, restoring loading pres-
sure to the pneumatic circuit. Reverse-acting control-
lers produce the opposite effect.
Maintenance
The 2500 and 2503 Series controllers/transmitters
work in combination with 249 Series displacers. Refer
to figure 19 for key number locations, unless otherwise
indicated.
Due to the care Fisher Controls takes in meeting all
manufacturing requirements (heat treating, dimension-