22
“Resetting Model DDX Double Interlock Type D
Preaction Systems.”
For Valve Sizes: 4" (100 mm), 165 mm, 6"
(150 mm) with Drop‑In Seat Configuration
only, Refer to Fig. 8:
It is likely that the lower seat o-ring (#11, Fig. 8)
has remained at the bottom of the Deluge Valve
body’s bore. Discard this o-ring and clean the
bore. Lubricate the bore with o-ring grease and
place the lower o-ring on the step at the bottom
of the bore, verifying that it is in full contact with
the bore. Lubricate the bottom step and upper
o-ring (#11, Fig. 8) of the refurbished clapper-
seat subassembly. Insert the clapper-seat sub
assembly into the hand hole opening, lever
(#7, Fig. 8) first and rotating the clapper-seat
subassembly until the lever faces the outlet of
the deluge valve. Next rotate the clapper-seat
subassembly 90 degrees about the center axis
of the valve until the bottom of the clapper-seat
sub assembly faces the pushrod (#20, Fig. 8).
Then rotate the clapper-seat subassembly 90
degrees counterclockwise so that the clapper
(#3, Fig. 8) is facing the outlet of the deluge
valve and the lever (#7, Fig. 8) is facing the
pushrod (#20, Fig. 8). Once the clapper seat
subassembly is in this position simply slide the
assembly into the bore of the valve, making
sure it is straight to avoid binding of the seat
in the bore. Slightly twisting the assembly will
assist in getting the clapper-seat subassembly
properly seated. Once it is verified that the
clapper-seat sub assembly is in the fully down
position and the lever (#7, Fig. 8) is aligned with
the pushrod (#20, Fig. 8), clean and lubricate
the two locking pins (#17, (not shown) Fig. 8)
with o-ring lubricant. Slide the two locking pins
into the deluge valve body to lock the seat in
place. Slightly twisting and pressing down on
the clapper-seat subassembly will help the
pins to slide in more easily. Then reinstall the
3
/
8
" NPT pipe plugs (#19, (not shown) Fig. 8).
Reassemble the hand hole cover (#4, Fig. 8)
and set up the Model DDX Deluge Valve as
per the section “Resetting Model DDX Double
Interlock Type D Preaction Systems”.
3. Leakage out of the push rod chamber vent hole:
A small bleed hole is located on the underside of the
push rod chamber (see Fig. 7 or Fig. 8). If there is air or
water leakage coming out of this hole, do the following:
a) Shut down the valve controlling water supply to the
Deluge Valve. Relieve the inlet pressure by opening
the 1-
1
/
4
" main drain valve on the 2" (50 mm), 2-
1
/
2
"
(65 mm), 76 mm and 3" (80 mm) valve sizes or the
2" main drain valve on the 4" (100 mm), 165 mm,
6" (150 mm) and 8" (200 mm) valve sizes, valve B
(Fig. 9). Close the valve A (Fig. 9) that supplies water
to the push rod chamber, and open the Model B
Manual Emergency Station, valve D (Fig. 9).
b) Remove the trim at the unions nearest to the push
rod chamber cover (#3, Fig. 9).
c) Take the push rod chamber cover (#3, Fig. 7 or #8,
Fig. 8) off by removing the six retaining screws (#26,
Fig. 7 or #29, Fig. 8).
CONDITION ONE (Water coming out of the
bleed hole):
Water coming out of the bleed hole is caused by
a leaking diaphragm (#18, Fig. 7 or #34, Fig. 8).
Visually inspect the push rod chamber cover (#3,
Fig. 7 or #8, Fig. 8), piston (#17, Fig. 7 or #18,
Fig. 8) and valve bore (#1, Fig. 7 or #1, Fig. 8) to
determine what could have damaged the diaphragm
and correct. Install a new diaphragm.
NOTE:
The
diaphragm has two different surfaces; it is not
bi-directional. It will fail if installed backwards!
Roll the diaphragm so that the smooth surface (the
pressure side) conforms to the inside of the push
rod chamber cover and reassemble the six retaining
screws (#26, Fig. 7 or #29, Fig. 8) with an installation
torque of 15 foot-pounds. Set up the Model DDX
Deluge Valve as per the section “Resetting Model
DDX Double Interlock Type D Preaction Systems.”
CONDITION TWO (System Air coming out of
the bleed hole):
System air coming out of the bleed hole is caused
by a defective O-ring assembled to the push rod
guide (#11, Fig. 7 or #9, Fig. 8). Remove the piston-
push rod subassembly, push rod spring (#34, Fig. 7
or #32, Fig. 8), and push rod guide (#11, Fig. 7
or #21, Fig. 8). Verify by hand turning, that the
push rod cannot be unscrewed from the piston.
Replace all O-rings and the push rod guide (#21,
#22 & #11, Fig. 7 or #9, #12 & #21, Fig. 8). The
correct installation torque for the pushrod guide is
35 inch-pounds.
CAUTION:
Do not over tighten
the push rod guide.
Reassemble the components
that were initially removed. Re-install the diaphragm
(#18, Fig. 7 or #34, Fig. 8) if it appears to be in
good shape, otherwise, replace it also.
NOTE:
The
diaphragm has two different surfaces; it is not
bi-directional. It will fail if installed backwards!
Roll the diaphragm so that the smooth surface (the
pressure side) conforms to the inside of the push
rod chamber cover and reassemble the six retaining
screws (#26, Fig. 7 or #29, Fig. 8) with an installation
torque of 15 foot-pounds. Set up the Model DDX
Deluge Valve as per the section “Resetting Model
DDX Double Interlock Type D Preaction Systems.”
