3-22. CONTROL VALVE ASSEMBLY MAINTENANCE (CONT)
g. Circuit Relief Valves (Cont).
CLEANING AND INSPECTION
Dry cleaning solvent P-D-680 used to clean
Wear protective goggles and gloves and
parts is toxic and flammable.
use only in a well ventilated
area. Avoid contact with skin, eyes and clothes and dont breathe
vapors. Do not use near open flame or excessive heat and dont smoke
when using it. Failure to do so could cause serious injury. If you be-
come dizzy while using cleaning solvent, get fresh air and medical
If contact with skin or clothes is made, flush
with large amounts of water.
If contact with eyes is made, wash eyes
with water and get medical aid immediately.
Clean all parts using cleaning solvent P-D-680. Dry using clean cloths.
Inspect control valve body for cracks, breaks, or other damage. Inspect
control valve bore for grooves, deep scratches, or other visible wear.
Replace entire control valve if control valve body requires replacement.
Check that free length of spring (5) is 1.027 inches. Replace spring if
free length is not as specified above. Replace spring if cracked, broken,
distorted, or deformed.
Check that free length of spring (16) is 0.99 inch. Use spring gage and
check that force required to compress spring to 0.625 inch is 0.9 to 1.1
pounds. Check that force required to compress spring to 0.437 inch is
1.35 to 1.65 pounds. Replace spring if free length or force required to
compress it is not as specified above.
Inspect adjusting screw (4) and plunger (6) for cracks, breaks, chipping,
or burrs. Replace if any of these conditions are seen.
Inspect body (1) and poppet (17) for cracks, breaks, chipping, or burrs.
Replace if any of these conditions are seen. Put poppet in body and check
that it moves freely without binding. If poppet does not move freely, re-
place it. Put plunger (6) in body and check that it moves freely without
binding. If plunger does not move freely, replace it.
Inspect remaining parts for cracks, breaks, deformation, distortion, or
damaged or stripped threads.