12
MAINTENANCE MANUAL MODELS 825Y, 825YA, 825, 825D, 825YD & 826YD
5. Relief Valve Seat Removal Model 825Y
(
3
/
4
–2")
Standard only on units manufactured after October of 1988 with
serial numbers higher than listed below. See Figure No. 11 for
exploded view of this relief valve.
Serial #‘s of new Model 825Y
with replaceable valve seat ring:
1
/
4
" Serial No. S6528 and above
1" Serial No. S6163 and above
1
1
/
2
" Serial No. S5710 and above
2" Serial No. S5089 and above
a.
While relief valve is disassembled, remove the two Allen
head socket capscrews using the appropriate sized Allen
head wrench. (
3
/
16
" Allen head wrench for
3
/
4
" and 1" assem-
blies, and
1
/
4
" Allen head wrench for 1
1
/
2
" and 2" assemblies.)
b.
Pull the relief valve body from the main valve body. Pull the
discharge shield from the seat ring
c.
Remove seat ring with the appropriate sized socket or
needle nose pliers. Use care to avoid damage to the seat
edge. Replaceable relief valve seat is standard only on units
manufactured after October of 1988.
d.
Inspect seat ring, o-rings, bushings, and gasket seals for
damage. Rinse all parts with clean water before reassembly.
d.
Close the #4, #3, and #2 test cocks and slowly open first
the inlet and then outlet shutoff valves and return the
assembly to service. See Figure No. 7 for test cock loca-
tions.
e.
Test the assembly to ensure it is operating properly.
4. Relief Valve Inspection/Repair Model 825Y
(
3
/
4
–2") (See Figure No. 11)
a.
Slowly close the inlet and outlet shutoff valves and bleed off
the residual pressure by opening first test cocks # 4, then #
3 and # 2. See Figure No. 7 for test cock locations.
b.
Remove capscrews, diaphragm cover, diaphragm and port
bushing of relief valve.
c.
Remove the integral relief valve assembly by pulling straight
out of the body to remove the internal assembly.
d.
Remove the disc washer and seat disc by unthreading the
screw.
e.
To remove spring and/or main stem from the guide, keep
unit compressed and remove the screw (item 18) located in
the center of the button. Push the main stem through the
guide and remove the o-ring from the main stem. Inspect
and clean or replace o-ring and seat disc as required. Clean
all parts thoroughly with clean water before reassembly.
Service Procedure 825Y and YA (
3
/
4
–2") (Continued)
