MAIN FLOW CONTROL POPPET
AND RELIEF VALVE SUBASSEMBLY
snugly without binding through a complete revo-
lution. Examine all O-rings and back-up rings for
Remove relief valve Poppet subassembly (18)
from inlet section. Begin disassembly by removing
snap ring (1), plug (2) with associated parts intact,
s p r i n g (3), poppet (4) and piston (5). Remove
O-rings (6, 7, 8, & 9) and back-up rings (10, 11.
12, & 13). If associated parts in the plug (2) are re-
m o v e d , relief pressure setting will be altered.
Coat all parts with hydraulic oil. Insert poppet
Finish disassembly by removing lock nut (15) ad-
(17) and spring (14) into plug (2). Install adjusting
just screw (16). spring (14) and poppet (17).
screw (16). After the adjusting screw contacts the
spring (14) each complete turn represents a pres-
sure increase of approximately 600 psi (42,18 kg./
cm.2) on the 475 and 1600 psi (112,49 kg./cm.2) on
the 175 and 275. When required pressure setting is
attained, Install lock nut (15) and apply 30 ft. lb.
(216,99 kg. mtrs.) of torque. Assemble O-rings (6, 7,
C l e a n all parts in solvent and dry with com-
8. & 9) and back up rings (10, 11, 12 & 13). Insert pis-
pressed air. Inspect O-ring grooves for contamina-
ton (5) and spring (3) into poppet (4), install as an
tion. Check springs for breaks or distortion.
assembly into poppet (18). Insert plug (2) with as-
Examine poppets (4 & 17), faces and correspond-
sociated parts into poppet (18) and install snap ring
i n g seating surfaces in poppet (18) and plug (2)
(1). Assemble relief valve subassembly in inlet sec-
for scratches or excessive wear. All seats must be
tion. To function properly as a flow control valve it
sharp and free of nicks. With O-ring and back-up
m u s t fit snugly without binding through a com-
r i n g removed, insert poppet (4) into poppet sub-
a s s e m b l y (18) and test for fit. Poppet must fit