Page 3 of 8 (Section 1 of 2)
I&M No.V7544-Sec.1
50 Hanover Road, Florham Park, New Jersey 07932 www.ascovalve.com
WARNING: To prevent the possibility of death,
personal injury or property damage, check valve
for proper operation before returning to service.
Also perform internal seat and external leakage
tests with a nonhazardous, noncombustible fluid.
12. Restore auxiliary and main line pressure to valve.
Valve Disassembly for 3/4
I
or 1
I
NPT Valves
1. Disassemble valve in an orderly fashion using exploded view for
identification and placement of parts.
2. A 4-40 machine screw provided in ASCO Rebuild Kit serves as a
self-tapping screw to remove insert from body. Thread screw a few
turns into through hole located in flat surface of the insert.
CAUTION: Do not damage center hole (pilot orifice) in
raised surface of insert.
3. Remove insert by using a pair of pliers to grip the head of the screw.
Then pull insert with gaskets from body insert cavity.
4. Remove three gaskets from insert. Tag each as they are removed so
that they can be reassembled in the same location. Middle and lower
gaskets are the same size, however, the lower gasket is a softer material.
Then remove disc holder sub-assembly and disc holder spring.
5. Remove long body screws with lockwashers (4) from piston end body.
Slip piston end body off piston/shaft sub-assembly.
6. Remove small body gaskets (2) from counterbores in piston end body.
7. Slide piston/shaft sub-assembly from main valve body. The
piston/shaft sub-assembly is comprised of the main shaft, shaft nut,
shaft washer, piston, body u-cup, guide u-cup, shaft gasket, piston
guide, seat gasket, guide gaskets (2) and a resilient main disc.
8. Disassemble piston/shaft assembly by inserting a brass rod (of suitable
size) into cross hole in shaft. Rod must be brass or made of another
soft material, so as not to burr edges of hole. Hold piston shaft firmly
(with rod) and unscrew shaft nut.
9. Disassemble piston/shaft sub-assembly in an orderly fashion. Be
careful not to damage or mar any of the parts.
10. Remove shaft nut, shaft washer, piston with body and guide-u-cups
(2) attached from shaft. Then remove body u-cup and guide u-cup
from piston.
11. Remove shaft gasket, piston guide, guide gaskets (2) seat gasket, and
resilient main disc.
12. Remove short body screws with lockwashers (4) from opposite end of
main valve body. Remove body/seat gasket and seat gasket from seat.
Then remove the other resilient main disc from bore of main valve
body.
13. All parts are now accessible to clean or replace. If parts are worn or
damaged install a complete ASCO Rebuild Kit.
Valve Reassembly for 3/4
I
or 1
I
NPT Valves
1. Lubricate body/seat gasket, seat gasket, upper, middle and lower insert
gaskets with DOW CORNING
r
200 Fluid lubricant or an equivalent
high-grade silicone fluid lubricant.
2. Lubricate all remaining gaskets, u-cups, bores of piston, piston end
body, main disc sliding area on the main shaft and valve body insert
cavity (see Figure 3) with a light coat with DOW CORNING
r
111
Compound lubricant.
3. Preassemble piston/shaft sub-assembly as follows:
A. Position resilient main disc on shaft so that resilient lip side of
disc is facing the piston guide.
B.
Install seat gasket and guide gaskets (2) on piston guide.
C. Slip piston guide with gaskets onto shaft.
D. Position shaft gasket on shaft.
E.
Install guide u-cup and body u-cup on piston. Make certain
that open end of guide u-cup faces, the main valve body, while
open end of body u-cup faces the piston end body. Position the
piston with u-cups on shaft.
F.
Replace shaft washer and shaft nut. Torque the shaft nut to 125
± 10 in-lbs [14,1 ± 1,1 Nm] while holding the shaft as described
in
Valve Disassembly
for 3/4
I
or 1
I
NPT valves section step 9.
4. Install piston/shaft sub-assembly in main valve body.
5. Position small body gaskets (2) in counterbores in piston end body.
6. Slip piston end body over the piston/shaft sub-assembly. Then install
long body screws with lockwashers (4). Torque the long body screws in
a crisscross manner to 40 ± 5 in-lbs [4,5 ± 0,6 Nm].
7. Install resilient main disc at opposite end of main shaft. Be sure
resilient side of disc is facing seat.
8. Position seat gasket and body/seat gasket on seat.
9. Install seat with gaskets into main valve body. Replace short body
screws with lockwashers (4). Torque body screws in a crisscross
manner to 40 ± 5 in-lbs [4,5 ± 0,6 Nm].
10. Position lower insert gasket and disc holder spring in body insert cavity.
11. Snap upper and middle insert gaskets into grooves of insert. Lower
insert gasket fits into the recess between the lower corner of the insert
and the lower corner of the body insert cavity. Middle and lower insert
gaskets are the same size. However, the lower gasket is made of a softer
material.
12. Place disc holder sub-assembly into insert. Install insert (with gaskets
and disc holder assembly) into body insert cavity, making certain that
the disc holder spring is centered. Rotate this assembly slightly while
pushing downward to aid installation.
WARNING: To prevent the possibility of death,
personal injury or property damage, check valve
for proper operation before returning to service.
Also perform internal seat and external leakage
tests with a nonhazardous, noncombustible fluid.
13.
Restore auxiliary and main line pressure to valve.
Disassembly of Manual Operator
1. Unscrew solenoid base sub-assembly from manual operator body.
2. Unscrew manual operator body from valve body. Then remove stem
retainer from base of manual operator body and stem/spacer
sub-assembly.
3. Pull stem/spacer sub-assembly with stem gasket from side of manual
operator body. Then remove core assembly with core spring, solenoid
base gasket and manual operator bonnet gasket.
4. For further disassembly refer to section on
Valve Disassembly
step 4.
Reassembly of Manual Operator
1. Lubricate manual operator stem gasket with DOW CORNING
r
111
Compound lubricant or an equivalent high-grade silicone grease.
2. For AC/DC construction (Figure 2A), install core assembly with spring
and core guide..
3. Holding the manual operator body in a vertical position, install core
assembly with core spring from the bottom end.
4. Insert the stem/spacer sub-assembly with the stem gasket into the side
hole of the manual operator body. Rotate the lever of the stem/spacer
sub-assembly to the 12 o'clock position.
5. Install stem retainer on base of manual operator body and
simultaneously engage it into the slot provided on the stem/spacer
sub-assembly.
IMPORTANT: The spacer on the stem/spacer sub-assembly
must
be outside
of the stem retainer for AC/DC construction (Figure 2B).
