Manual
8
DRAWING I
RETAINER CLIP
SEAT
OUTER LINK
INNER LINK
DRAWING II
MAINTENANCE INSTRUCTIONS:
Ames back ow prevention assemblies require mini-
mum maintenance. Maintenance on all internal com-
ponents can be performed without removal of the
assembly from line service. All assemblies must be
retested once maintenance has been performed.
Removing and Installing Knuckle Joint
Assembly (2000DCA and 3000DCDC)
1. Shut down water system and lockout system if
possible.
2. Slowly open test cocks or air bleed screw to
relieve pressure.
3. Remove all cover plate bolts, lid and cover plate
gasket from valve body.
4. Push retainer clip into knuckle joint retention
openings located on inner and outer linkages of
knuckle joint assembly, until clapper open slightly.
(Drawing I).
5. Carefully loosen and remove the two knuckle joint
mounting bolts, located on exterior of valve body.
6. Remove knuckle joint assembly from body as-
suring retainer clip is not disturbed.
7. Bolt the knuckle joint assembly on the exterior of the
body through the mounting link holes (Drawing II),
or press on hard surface to remove retainer clip.
8. Push on clapper plate to release retainer clip, and
remove clip. Slowly remove tension on clapper
and unbolt knuckle joint assembly from mounting
link holes.
9. Bolt replacement knuckle joint assembly as in step
7 FT LBS.
10. Push on clapper plate to extend spring and install
retainer clip. Unbolt knuckle joint assembly from
mounting link holes.
11. Insert two New
3
⁄8 x 1" sealed mounting bolts
through mounting holes in body. Position knuckle
joint in place inside body, and nger tighten both
bolts.
12. Torque knuckle joint mounting bolts to approxi-
mately 10 FT LBS.
13. Remove retainer clip
14. Install new gasket with lid. Torque lid bolts to 120
FT LBS.
Removing And Installing Knuckle Joint
Assembly (#1 check valve on 4000RP,
1st and 2nd check on 10" (250mm)
2000 DCA and 3000DCDC).
1. Depressurize assembly.
2. Remove all cover plate bolts, cover and gasket
from #1 check.
3. Locate pivot arm of tong tool onto horizontal link
pin of knuckle joint (Drawing III).
4. Locate pivot arm of tong tool into adjacent port
ange hole.