Watts 774 - Manual (Page 4)

4
Removing Check Assemblies –
Before servicing be certain shut off valves
are closed
1. Slowly open all ball valves to relieve air and water pressure.
Loosen bolts on groove coupler and remove groove coupler
and cover plate from valve body.
2. Remove #1 Check assembly by using your hands to
unscrew (turn counterclockwise) Check and remove through
top access port. Do not use Arm as a handle to unscrew.
If Check can not be loosened by hand, insert a long screw-
driver between valve body and Check (see Figure 3). Slowly
apply pressure against the Check until loosened. Finish
unscrewing by hand. Unscrew #2 Check (turn counterclock-
wise) by placing a long screwdriver between lugs and apply-
ing pressure to loosen #2 Check. Finish unscrewing by hand.
3. To clean #1 Check, (6' and 8" only) locate the Check Arm
opening stud on the outlet flange of the valve assembly.
Slide the Check Arm over the stud with the check threads
facing downward (Figure 1). Tighten 1 ⁄
4
" nut on stud to secure
Check bar.
Slowly pull the assembly outward to open check allowing expo-
sure of the seat and clapper contact area for cleaning. To clean
#2 Check, lift Check Arm and hold in open position. Raise clap-
per so that the end of the Check Arm rests between roller and
clapper (Figure 2). Thoroughly clean the seat area and clapper
sealing surfaces of both Checks. Inspect seats, clapper sealing
surfaces, Check Arms, and O-rings for damage. If not damaged
gently close the clapper. If damaged, install a new Check as-
sembly and/or O-ring.
4. Before reinstallation of Checks thoroughly clean O-ring
groove and lubricate O-ring w/FDA approved lubricant. Insert
and thread #2 Check first and then #1 Check. #2 Check
should be tightened by inserting a long screwdriver between
lugs to tighten firmly. Do not over tighten. Tighten #1 Check
firmly by hand only. Replace cover plate, clean groove
coupler gasket and groove, replace groove coupler.
Servicing First and Second Checks
#1 Check 2 1 ⁄
2
"-6"
O-ring Seal &
Groove
Seat
O-ring Seal &
Groove
Cam Arm Spring
Clapper
Roller
Hole
6" & 8" only
#2 Check
O-ring Seal &
Groove
Lug
Seat
Spring
Cam Arm
Roller
Hole
6" & 8" only
O-ring Seal & Groove
Clapper
Threaded Stud on
Valve Outlet Flange
6" & 8" 1st Check DC
6" & 8" 2nd Check DC
Figure 1
Cleaning Position
Figure 2
Figure 3