19
Instruction Manual
7. Inspect the balls carefully. If they are smooth,
round and free of deposits or pits, they are
suitable for continued use. Examine the check
valve seats. The area of the seat in contact
with the ball (the un-chamfered side) must be
in near perfect condition for continued use.
Any visible imperfection on the seating surface
(pits, erosion, cracks) necessitates replacement
of the seat. If both the balls and the seats are in
good condition, then the length of time between
parts replacement may be increased. If the
balls and seats are severely damaged, then
the length of time between parts replacement
should be shortened. Carefully clean any
parts to be reused. If any chemicals are used
in the cleaning process, ensure that they are
compatible with the process liquid.
B. Reassembly
1. Drop the ball into the curved inner chamber end
of the ball guide.
2. Sit the ball guide on a flat surface so that the side
with the ball faces upwards. Position seat on the
ball guide, trapping the ball inside. When the
seat is pressed into the ball guide, the beveled
edge of the seat must be facing outward.
The bevel should not face the inside of the check
valve
(refer to Figure 11)
. Use a flat surface such
as a board to press the seat into the ball guide
with firm, even pressure.
IF THE SEAT IS IMPROPERLY
POSITIONED (WITH BALL
AGAINST BEVELED SURFACE), THE BALL WILL NOT CREATE
A TIGHT SEAL AND POOR PUMPING PERFORMANCE WILL
RESULT.
3. Fit new O-rings into grooves in the ball guide
and seat.
Note:
To assure a tight, leak free seal, new O-rings
should be used each time the check valves are
disassembled.
4. Position the union end (445) onto the correct
end of the ball guide. Refer to
Figure 11
as the
correct end is determined by whether the valve
is intended for the suction or discharge port of
the liquid end. Slip the union nut (435) over the
union end and screw tightly (hand tight only)
onto the ball guide.
THE ORDER OF ASSEMBLY OF
THE SUCTION AND DISCHARGE
CHECK VALVES IS DIFFERENT. REFER TO FIGURE 11 FOR
PROPER ASSEMBLY ORDER. IF CHECK VALVE CARTRIDGES
ARE INSTALLED INCORRECTLY, ONE OF THE FOLLOWING
WILL OCCUR: (A) IMMEDIATE SEVERE DAMAGE TO PUMP
MECHANISM, (B) NO PUMPING, (C) REVERSE PUMPING
ACTION (FROM DISCHARGE LINE INTO SUCTION LINE).
5. Screw the valve assembly into the liquid
end body(hand tight only).
DO NOT
OVERTIGHTEN!
1-1/4” Plunger, Plastic Double Ball Check
Valves
1-3/4”, 2-1/2”, 3” Plungers, Plastic &
Metallic Double Ball Check Valves
A. Disassembly
(Refer to Figure 10)
.
Double ball check valves differ from the plastic
single ball check in that the ball seat is now
integral to the ball guide. The seats cannot easily
be inspected for damage or wear. If you suspect
that the check valve may be damaged or worn,
replace the entire check valve assembly as per
instructions below.
1. If metallic valve, unscrew the coupling (445)
from the ball guide (424). If plastic, unscrew the
union nut (435,
figure 11
) and remove union end
(445,
figure 11
) from the ball guide (424).
2. Unscrew the ball guide (424) from the liquid
end.
3. Remove and discard the O-rings (419).
4. Remove ball stop (420) and balls (421, 422).
SECTION 4 - MAINTENANCE
