American Backflow CLA-VAL RP-4 User manual

Model RP-4
2” - 10”

Product Overview
RP-4 (1991-2005) Utilized the 3084 Toggle Lever
Checks and CDHS-24 relief valve.
2” size was discontinued in 2003
Replacement hardware parts were discontinued in
2005. Only Repair kits with rubber parts are
available.

Check Cover Removal
The check covers are secured by bolts and sealed by an o-ring.
2” through 6” sizes remove all but two cover bolts, leaving two bolts 180
degrees apart. Press down on the cover while removing the last two
bolts to prevent the cover from being forcibly ejected by the spring.
8” and 10 sizes, it is suggested that all-thread rod and nuts (jack
screws) be used when removing or replacing the covers. The 8” size
uses two 5/8”-11 all-thread approximately 8” long. The 10” size uses
two ¾” -10 approximately 8” long. Remove two cover bolts on opposite
sides of the cover, and install all-thread rod. Install and tighten nuts
down to cover. Remove remaining cover bolts. Simultaneously, back
the jack screw nuts off until the spring tension is completely released.
Remove the cover.

Check Valve Removal
Remove the two pipe plugs on
each side of the valve body, to
expose the lever arm pin (item
13) and the hinge pin (item 11).
Using a brass rod (smaller in
diameter than the pins), gently
tap out the rear lever arm (item
13) pin first.
CAUTION: Support the lever
arm (item 10) while completely
removing the lever arm pin. Let
the lever arm rest gently in the
bottom of the check valve.

Check Valve Removal
Grasp the yoke (item 7) with
one hand, while removing the
front hinge pin (item 11). Lift
out the toggle- lever clapper
assembly, being careful that
the brass seat is not dented.
NOTE: On 8” & 10” sizes, a
lever arm spacer (item 26) is
installed between the two
lever arms to maintain proper
distance between them, and
prevent binding.

Check Valve Disassembly
2” through 8” sizes remove the
retaining bolt (item 23) from the
center of the disc guide.
10” sizes (only) remove sixteen
retaining screws from the disc
guide (item 5).
The check disc is free once the
guide is separated from the disc
retainer (item 4).
NOTE: An o-ring (item 20) is
installed on the retaining bolts
for sizes 21/2”, 3”, 4”, 6”, and 8”.

Check Seat Service
Check seats are o-ring sealed and pressed into
the body.
Replacement seats are no longer in production.
Very fine nicks on the seating edge can be
restored by slowly working 400 wet or dry
sandpaper back and forth on both sides (top and
inner throat) of the seat.

Check Disc Replacement
When installing a new check disc, fiber
spacer washers between the retainer and
guide MAY or MAY NOT be required.
Fiber spacer washers (item 33) are installed
to ensure the proper “squeeze” on the disc
(item 6).
Too many washers will not allow sufficient
squeeze on the disc (not a water tight seal).
This will cause the check valve to fail.
Too few washers between the guide and
retainer can generate TOO MUCH squeeze
on the disc, causing it to bulge around the
guide. This will also cause the check to fail.
Proper squeeze on the disc is achieved when
the disc cannot be rotated and no bulge
appears.

Check Valve Alignment
Re-install clapper assembly. Be
careful not to damage check seat.
Support clapper assembly with one
hand and install hinge pin.
With clapper assembly supported by
hinge pin only, exert pressure to
force disc against the seat, and
leave an imprint of the seat in the
disc.
Remove clapper assembly. Inspect
disc to ascertain that alignment is
correct.

Check Valve Alignment
In the event the seat imprint
indicates an incorrect alignment,
adjust hinge pin bushing OUT, on
the side that corresponds to the
least distance between the seat
imprint and disc guide.
In this figure, adjust hinge pin
bushing on the RIGHT side
outward.
Alignment is correct if the seat
leaves an imprint on the disc equi-
distant on all sides of the disc
guide.