Watts 957 Serie Manual De Instalación Y Mantenimiento página 3

Maintaining the Check Modules
2 ⁄ " – 6"
1
2
Housing
Figure A
Check No. 1
Figure D
Check No. 2
Figure D
! WARNING
Before servicing any Watts valve, it is mandatory to shut down
the water system by closing both the inlet and outlet shutoff
valves. After the shutoff valves are closed, open test cocks
No. 2, No. 3, and No. 4 to relieve pressure within the backflow
assembly.
1. After test cock No. 3 has been opened to relieve pressure,
remove the test cock from the housing. (See 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 a quarter turn clockwise and a quarter turn
counterclockwise to break the sleeve O-ring seals. Using the
screwdriver, slowly slide the cover sleeve to the downstream
side of the housing. (See Figure B.)
3. Remove the stainless steel check retainer from the housing.
(See Figure B.)
4. Remove the check No. 1 module 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.
(See Figure C.)
Figure B
Figure E
Figure E
5. Repeat step 4 to remove check No. 2 module. (For servicing
6" checks, see the maintenance instructions for valve sizes
8" to 10".)
6. To clean or inspect either check module, insert a #3 screw-
driver through the downstream side of the check module.
(See Figures D and E.) When the screwdriver is in place,
remove the E-clip and pin connecting the structural members.
(See Figure F.) The check clapper opens with no tension.
7. Thoroughly clean the seating area. The sealing disc can be
removed, if necessary, by detaching the screws connecting
the keeper plate to the clapper. Reverse and reinstall the
sealing disc if the elastomer is cut or damaged.
8. Wash the check module and O-ring and inspect for any
damage. If damaged, reinstall new parts.
9. After a thorough cleaning, lubricate the O-ring with an FDA
Approved lubricant, replace the pin and E-clip in the structural
members, remove the screwdriver, and reinstall the check
modules. Reverse the order of these steps to reassemble the
parts and housing.
Figure C
Figure F
Figure F
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