Installation, Maintenance, & Repair
Series 957, 957RPDA, LF957RPDA
Reduced Pressure Zone Assemblies
Reduced Pressure Detector Assemblies
Sizes: 21⁄2" – 10" (65 – 250mm)
RP/IS-957/957RPDA
957 OSY
WARNING
!
You are required to thoroughly read all installation instructions
and product safety information before beginning the installation of this product. FAILURE TO COMPLY WITH PROPER
INSTALLATION AND MAINTENANCE INSTRUCTIONS
COULD RESULT IN PRODUCT FAILURE WHICH CAN
CAUSE PROPERTY DAMAGE, PERSONAL INJURY AND/
OR DEATH. Watts is not responsible for damages resulting from
improper installation and/or maintenance.
Local building or plumbing codes may require modifications to
the information provided. You are required to consult the local
building and plumbing codes prior to installation. If this information is not consistent with local building or plumbing codes, the
local codes should be followed.
Need for Periodic Inspection/Maintenance: This product
must be tested periodically in compliance with local codes, but
at least once per year or more as service conditions warrant.
Corrosive water conditions, and/or unauthorized adjustments
or repair could render the product ineffective for the service intended. Regular checking and cleaning of the product’s internal
components helps assure maximum life and proper product
function.
NOTE: For Australia and New Zealand: Pipeline strainers should
be installed between the upstream shutoff valve and the inlet of
the backflow preventer.
It's important that this device be tested periodically in compliance with local codes, but at least once per year or more as
service conditions warrant. If installed on a fire sprinkler system,
all mechanical checks, such as alarm checks and backflow
preventers, should be flow tested and inspected internally in accordance with NFPA 13 and NFPA 25.
Testing
For field testing procedure, send for IS-TK-DL, IS-TK-9A, IS-TK99E AND IS-TK-99D.
For other repair kits and service parts, send for PL-RP-BPD.
For technical assistance, contact your local Watts
representative.
Installation Instructions
Series 957, 957RPDA, LF957RPDA
Guidelines
1. Most field problems occur because dirt and debris are present in the system at the time of installation and becomes
trapped in the #1 check. The system should be flushed
before the backflow valve is installed. If the system is not
flushed until after the backflow valve is installed, remove both
check modules from the valve and open the inlet shutoff to
allow water to flow for a sufficient time to flush debris from
the water line. If debris in the water system continues to
cause fouling, a strainer can be installed upstream of the
backflow assembly.
2. Watts Series 957, 957RPDA and LF957RPDA may be installed in either horizontal, “N” pattern, or “Z” pattern position
as long as the backflow assembly is installed in accordance
with the direction of the flow arrow on the assembly and the
local water authority approves the installation.
3. The assembly should be installed with adequate clearance
around the valve to allow for inspection, testing and servicing. 12" (305mm) should be the minimum clearance between
the lower portion of the assembly and the floor or grade. The
valve should be protected from freezing.
4. Installing a backflow preventer in a pit or vault is not recommended.
5. Normal discharge and nuisance spitting are accommodated
by the use of a Watts air gap fitting and a fabricated indirect
waste line. Floor drains of the same size must be provided in
case of excessive discharge.
6. The 957, 957RPDA and LF957RPDA backflow preventer
should be tested by a certified tester at the time of installation.
NOTE: Assembly body should not be painted.
Horizontal Installation
N Pattern
Z Pattern
lpm gpm
1330 350
1140 300
950 250
760 200
570 150
Rate of Flow
380 100
190 50
0 0
Relief Valve Discharge Rates 21⁄2" – 10" (65 - 250mm)
957, 957RPDA and LF957RPDA
0 20 40 60 80 psi
0 138 276 413 551 kPa
Pressure
2
Maintenance Instructions
Series 957, 957RPDA, LF957RPDA
21⁄2" – 6" (65 – 150mm)
Figure A
#1 Check Diagrams
Figure D
#2 Check Diagrams
Figure D
Prior to servicing any Watts valve, it is mandatory to shut down
the water system by closing both the inlet and outlet shutoff
valves. After shutoff valves are closed, open test cock #2, #3
and #4 to relieve pressure within the backflow assembly.
1. After #3 test cock has been opened to relieve pressure, remove #3 test cock from housing. (Figure A)
2. Insert a #3 screwdriver through the hole on the top of the
cover sleeve and using both hands rotate the cover sleeve approximately
to break the sleeve O-ring seals. Using the screwdriver, slowly
slide the cover sleeve to the downstream side of the housing.
(Figure B)
3. Remove the stainless steel check retainer from the housing.
(Figure B)
4. Remove the #1 check module (Figure C) by inserting two flat
blade screwdrivers into the slots on either side of the check
module and gently pry the check module toward the open
zone.
1
⁄4-turn clockwise and 1⁄4-turn counter-clockwise
Figure B
Figure E
Figure E
5. Remove #2 check module with the same instructions as in #4
above. For servicing 6" (150mm) checks see 8" – 10" (200 –
250mm) instructions on p. 4.
6. To clean or inspect either check module, insert a #3 screwdriver through the downstream side of the check module as
shown in Figure D and E. When the screwdriver is in place,
remove the E-clip (Figure F) and pin connecting the structural
members and the check clapper will open with no tension.
7. Thoroughly clean the seating area. The sealing disc may be
removed, if necessary, by removing the screws connecting the keeper plate to the clapper. The sealing disc may be
reversed and reinstalled if the elastomer is cut or damaged.
8. Wash check module and O-ring and inspect for any damage.
If damaged, reinstall new parts.
9. After thorough cleaning, lubricate O-ring w/FDA approved lubricant, replace pin and E-clip in structural members, remove
screw driver and reinstall check modules and assemble housing in reverse order of these instructions.
Figure C
Figure F
Figure F
3
Maintenance Instructions
Series 957, 957RPDA, LF957RPDA
8" – 10" (200 – 250mm)
Material–Tool Requirements:
• #3Phillipsscrewdriveror5/16" diameter rod, length sufficient
to span diameter of check, see Figures A and B.
1
•
/2 – 13 x 5 fully threaded hex bolt (Service bolt).
3
•
/4" open end or socket wrench.
Instructions
Prior to servicing any Watts valve, it is mandatory to shut
down the water system by closing both the inlet and outlet
shutoff valves. After shutoff valves are closed, open test cock
#2, #3 & #4 to relieve pressure within the backflow assembly.
1. After #3 test cock has been opened to relieve pressure, remove #3 test cock from housing.
When repairing an 8" or 10" (200 or 250mm) device, remove
both Victaulic couplers from body. Slide the downstream Victaulic coupler gasket to the downstream side of the housing.
The upstream Victaulic coupler gasket stays in place.
2. Remove checks that are to be serviced.
3. Locate the service hole and thread in the service bolt by hand
until it contacts the linkage. (Figure A)
4. Continue to thread in service bolt with the wrench until the
service hole in the linkage is aligned with the service notches
on the spring arbors. (Figure A)
5. Insert the Phillips screwdriver through the arbors and service
hole of the linkage making sure that the tip of the screwdriver
extends past the ends of the arbors by a minimum of
(6mm). (Figure B)
6. Back out the service bolt until load is transferred to the screwdriver. Continue to back out the service bolt until
sufficient clearance is achieved to remove the complete spring
mechanism.
7. To disconnect linkage, remove retaining clip and pin (store
in a safe location for reinstallation).
8. To remove spring mechanism, grasp the screwdriver at the
center and pull complete assembly straight out and store in
a safe place.
9. Reinstall in reverse order of these instructions.
WARNING:
While the spring mechanism is removed for check servicing;
never pull the screwdriver out or off the support notches on the
arbors. Doing so may cause bodily injuries.
1
/4"
Figure A
Service Hole
Figure B
4
Service Relief Valve
Series 957, 957RPDA, LF957RPDA
Prior to servicing the relief valve, it is mandatory to shut
down water system by closing both the inlet and outlet
shutoff valves and relieving pressure within the assembly
by opening the #2, #3 and #4 test cocks.
DO NOT REMOVE SPIDER BUSHING FOR SERVICING
1. Disconnect the hose from the bottom cover plate to the relief
valve.
2. An O-ring seals the relief valve body to the main housing. It
is not necessary to tighten the connection beyond firm hand
tightening. The relief valve should be able to be removed by
unscrewing the relief valve from the housing.
3. Remove the cover plate of the relief valve by removing the
four connecting screws.
4. Remove the rubber diaphragm from the relief valve. Be
aware of how the diaphragm is configured so that it can be
reinstalled in the same manner. The hard rubber tab in the
diaphragm fits into a similar socket in the head of the piston.
(Figure 1)
5. Hold the relief valve in both hands with the threaded end
up and both thumbs on the head of the piston. Push up on
the piston until the piston shaft with the attached E-clip is
exposed. Remove the E-clip (Figure 2)
6. Remove the piston and spring from the relief valve housing and thoroughly clean all parts including the diaphragm.
Inspect all rubber parts for damage and if damaged, replace
them with new parts.
7. Reassemble the relief valve in the reverse order that it
was disassembled.
Figure 1
Figure 2
5
Service, Replacement Parts and Maintenance
Series 957, 957RPDA, LF957RPDA
Sleeve O-ring and Gasket
Check Module O-ring
First Check Module
Relief Valve
Second Check Module
Repair Kits
1
/2" – 10" (65 - 250mm)
2
ORDERING NO. SIZE DISC MODEL
in. mm
1st Check Kits
*
7018129 21⁄2 - 4 65-100 EPDM RK 957/957RPDA CK1
0889370 21⁄2 - 4 65-100 RED SILICONE RK 957/957RPDA CK1-RS
7018132 6 150 EPDM RK 957/957RPDA CK1
0889374 6 150 RED SILICONE RK 957/957RPDA CK1-RS
7018135 8 200 RED SILICONE RK 957/957RPDA CK1
LEAD FREE
0899215 10 250 RED SILICONE RK 957/957RPDA CK1
Kit consists of: First check module, Check module O-ring and Disc elastomer.
2nd Check Kits
*
0899216 21⁄2 - 4 65-100 EPDM RK 957/957RPDA CK2
0889371 21⁄2 - 4 65-100 RED SILICONE RK 957/957RPDA CK2-RS
0899217 6 150 EPDM RK 957/957RPDA CK2
0889375 6 150 RED SILICONE RK 957/957RPDA CK2-RS
0899218 8 200 RED SILICONE RK 957/957RPDA CK2
LEAD FREE
0899219 10 250 RED SILICONE RK 957/957RPDA CK2
Kit consists of: Second check module, Check module O-ring and Disc elastomer.
1st or 2nd Check Rubber Parts Kits
*
0899220 21⁄2 - 4 65-100 EPDM RK 957/957RPDA RC4
0889372 21⁄2 - 4 65-100 RED SILICONE RK 957/957RPDA RC4-RS
0899221 6 150 EPDM RK 957/957RPDA RC4
0889376 6 150 RED SILICONE RK 957/957RPDA RC4-RS
0899222 8 200 RED SILICONE RK 957/957RPDA RC4
LEAD FREE
0899223 10 250 RED SILICONE RK 957/957RPDA RC4
Kit consists of: Check module O-ring, Disc elastomer and E-clip
Closure Sleeve Test Cock with O-ring
Closure Sleeve
E-clip
Disc, Elastomer for tight shutoff
ORDERING NO. SIZE MODEL
in. mm
Check Sleeve Cover Kits
*
0899240 21⁄2 - 4 65-100 RK 957/957RPDA C
0899241 6 150 RK 957/957RPDA C
0899242 8 200 RK 957/957RPDA C
0899243 10 250 RK 957/957RPDA C
LEAD FREE
Kit consists of: Closure sleeve, Sleeve O-ring and gasket.
ORDERING NO. SIZE DISC MODEL
in. mm
Total Rubber Parts Kits
*
0899244 21⁄2 - 4 65-100 EPDM RK 957/957RPDA RT
0889373 21⁄2 - 4 65-100 RED SILICONE RK 957/957RPDA RT-RS
0899245 6 150 EPDM RK 957/957RPDA RT
0889377 6 150 RED SILICONE RK 957/957RPDA RT-RS
0899246 8 200 RED SILICONE RK 957/957RPDA RT
LEAD FREE
0899247 10 250 RED SILICONE RK 957/957RPDA RT
Kit consists of: 1st and 2nd Check module O-ring, (2) Disc elastomer, (2) E-clips,
Relief valve diaphragm, Relief valve inlet coupler O-ring and Relief valve piston
assembly.
* The wetted surface of this product contacted by consumable
water contains less than 0.25% of lead by weight.
6
Service, Replacement Parts and Maintenance
Series 957, 957RPDA, LF957RPDA
Relief Valve Assembly
Body
Diaphragm
Cover Plate
Assembly
O-ring, Inlet Coupler
Relief Valve Kits
1
/2" – 10" (65 - 250mm)
2
ORDERING NO. SIZE MODEL
in. mm
Relief Valve Total Kit
LEAD
0899232 21⁄2 - 10 65-250 RK 957/957RPDA VT
*
FREE
Kit consists of: Complete relief valve assembly
Relief Valve Rubber Parts Kit
LEAD
*
0899236 21⁄2 - 10 65-250 RK 957/957RPDA RV
FREE
Kit consists of: Diaphragm, Inlet coupler O-ring and Piston assembly
Spider Bushing
Spring
Piston Assembly
Screw, Cover
ORDERING NO. USE FOR MODEL
Relief Valve Hose
0298120 21⁄2" – 4" (65-100MM) 957, 957RPDA
0298121 21⁄2" & 3" (65,80MM) 957,
957RPDA N & Z
0298122 6" (150MM) 957, 4" 957N
21⁄2", 3", 4" (65,80,100MM) 957Z
6", 8" (150,200MM) 957RPDA
4", 6", 8" (100,150,200MM) 957RPDA N & Z
21⁄2", 3", 4" (65,80,100MM) 957RPDA BFG
21⁄2", 3", 4", 6" (65,80,100,150MM)
957RPDA BFG N & Z
0298123 8" & 10" (200 & 250MM) 957
6", 8", 10" (150, 200, 250MM) 957 N & Z
10" (250MM) 957RPDA N & Z
6" & 8" (150, 200MM) 957RPDA BFG N & Z
ORDERING NO. SIZE MODEL
in. mm
1
⁄2 X 1⁄2 CFC-S-CFX20
1
⁄2 X 1⁄2 CFC-S-CFX24
1
⁄2 X 1⁄2 CFC-S-CFX30
1
⁄2 X 1⁄2 CFC-S-CFX36
Air Gap
0111764 21⁄2 – 10 65-250 957AG
0111815 21⁄2 – 10 65-250 957AG SPLASH GUARD
* The wetted surface of this product contacted by consumable
water contains less than 0.25% of lead by weight.
Troubleshooting Guide
Series 957, 957RPDA, LF957RPDA
Symptom Cause Solution
1. Relief valve discharges water a. #1 check is fouled Remove and Clean #1 check
while system is not flowing b. Relief valve does not properly close Service relief valve
c. Municipal water pressure is Install check valve upstream
fluctuating of backflow assembly
2. Relief valve does not a. Fouled relief valve seat Service relief valve
shut off properly b. Incorrectly Installed diaphragm Remove diaphragn and correctly install
c. Damaged rubber surface on piston Replace with new piston
d. Damaged or plugged pressure hose
7
For additional information, visit our web site at: www.watts.com
Limited Warranty: Watts Regulator Co. (the “Company”) warrants each product to be free from defects in material and workmanship under normal usage for a period of one year from the date of
original shipment. In the event of such defects within the warranty period, the Company will, at its option, replace or recondition the product without charge.
THE WARRANTY SET FORTH HEREIN IS GIVEN EXPRESSLY AND IS THE ONLY WARRANTY GIVEN BY THE COMPANY WITH RESPECT TO THE PRODUCT. THE COMPANY MAKES NO OTHER
WARRANTIES, EXPRESS OR IMPLIED. THE COMPANY HEREBY SPECIFICALLY DISCLAIMS ALL OTHER WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE IMPLIED
WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
The remedy described in the first paragraph of this warranty shall constitute the sole and exclusive remedy for breach of warranty, and the Company shall not be responsible for any incidental, special
or consequential damages, including without limitation, lost profits or the cost of repairing or replacing other property which is damaged if this product does not work properly, other costs resulting
from labor charges, delays, vandalism, negligence, fouling caused by foreign material, damage from adverse water conditions, chemical, or any other circumstances over which the Company has no
control. This warranty shall be invalidated by any abuse, misuse, misapplication, improper installation or improper maintenance or alteration of the product.
Some States do not allow limitations on how long an implied warranty lasts, and some States do not allow the exclusion or limitation of incidental or consequential damages. Therefore the above
limitations may not apply to you. This Limited Warranty gives you specific legal rights, and you may have other rights that vary from State to State. You should consult applicable state laws to
determine your rights. SO FAR AS IS CONSISTENT WITH APPLICABLE STATE LAW, ANY IMPLIED WARRANTIES THAT MAY NOT BE DISCLAIMED, INCLUDING THE IMPLIED WARRANTIES OF
MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE, ARE LIMITED IN DURATION TO ONE YEAR FROM THE DATE OF ORIGINAL SHIPMENT.
A Watts Water Technologies Company
USA:Tel:(978)688-1811•Fax:(978)794-1848•www.watts.com
Canada: Tel:(905)332-4090•Fax:(905)332-7068•www.watts.ca
RP/IS-957/957RPDA 1145 EDP# 1915342 © 2012 Watts
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