American Backflow CLA-VAL RP-1 User manual

Model RP-1
2” - 10”

Product Overview
RP-1 (1978-1985) Utilized the 3081
Toggle Lever Checks and CDHS-20 relief
valve.
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.
On 8” and 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).
An o-ring (item 20) is installed
on the retaining bolts for sizes
2 ½”, 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 (item
13), 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.