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.

Check Reassembly Notes
When the two pins that hold
the toggle-lever (clapper)
assembly are installed, be
sure to note that the yoke
(item 7) and the lever arm
pivots upward freely.

Relief Valve Cover Removal
The CDHS-20/ CDHS-24 RV
has two covers. The bellofram
cover (item 3) and the
intermediate body or
“diaphragm cover” (item 2).
The bellofram cover (item 3) is
located on top of the RV
assembly.
The bellofram cover is secured
by screws and sealed by the
bellofram.
There is no spring load on this
cover.

Relief Valve Cover Removal
The intermediate body (item 2) is
secured by cap screws and
sealed by the diaphragm.
There is a slight spring load on
this cover, so exert pressure
downward on the cover as the
cap screws are removed.
The RV stem assembly is
mounted through the
intermediate body.
The RV spring is free once cover
is removed.

Disassemble RV Stem
The stem is secured by the
upper and lower stem nuts
(item 16).
Remove the upper stem nut
first.
The bellofram, piston and
retainer can now be
removed from the upper
stem.
Remove the stem along
with the diaphragm and disc
from the body.

Disassemble RV Stem
Remove lower stem nut (item
16).
The RV disc (9), disc retainer (8),
and guide (10) are removed as
one assembly.(Simply pry disc
from retainer)
Remove the diaphragm (item13),
the lower stem o-ring (item 15)
and washer (item 7) from stem.

RV Seat Service
The RV seat is o-ring sealed and threaded into
the main RV 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.

Diaphragm Reassembly
Reassemble the diaphragm (item 13),
lower stem o-ring (item 15) and washer
(item 7) on the lower stem (4).
Reassemble the RV disc, disc retainer,
and guide as one assembly on the
lower stem.
The serrated area of the disc retainer
(8) is positioned against the diaphragm.
Insert the stem (4) with diaphragm and
disc retainer intact, into the intermediate
body.

Upper Stem Reassembly
Reassemble the bellofram (12), piston
(5), retainer (6) and stem o-ring (15) on
the upper stem and replace stem nut.
Position the retainer (6) with its outer lip
facing up.
Position the bellofram with the glossy
side against the retainer(6). The fabric
side against the piston(5)
Position the piston (5) with the recess
around the stem hole facing down
toward the o-ring (15).

Intermediate Body Reassembly
Position the RV spring over the
seat in the main body.
Insert cap screws through
intermediate body and diaphragm.
Make sure the sensing passage is
aligned properly.
Press the intermediate body down
on the main body and start cap
screws.
Be sure to evenly cross tighten cap
screws.

Bellofram Reassembly
Carefully push bellofram(12)
“brim” straight down over itself so
that the “brim” is flat and smooth
against the intermediate body.
Make sure the bellofram is not
twisted or wrinkled.
Install cover (3) so that weep
hole faces out away from
backflow.
Do not rotate cover after placing
over the “brim”, this can twist and
tear the bellofram.