Val-Matic Tilted Disc Check Valve - Manual (Page 6)

5
WARNING
The line must be drained before removing the
valve or pressure may be released causing
injury.
DISASSEMBLY OF BASIC VALVE
The valve should be removed from the pipeline for
disassembly. All work on the valve should be
performed by a skilled mechanic with proper tools.
Refer to Figure 2.
1. Lay valve on flat surface or bench with the inlet
flange face down.
2. Using a flat-nosed punch, drive out the two
locating pins (27).
3. Remove the indicator jam nut (26), lockwasher
(25), pointer (22), pivot pin cover bolts (18) and
covers (16).
4. Remove the pivot pins (4). The end of the pin is
tapped for insertion of a 9/16”-18 or 3/4”-16
threaded rod.
5. Attach a hoist to the outer flange of the valve to
support the weight of the outlet body section of
the valve and remove the diagonal flange bolts
(7).
6. Using the hoist, raise the outlet body section of
the valve. If the valve sections are joined tightly
by the gasket, lift the valve 1/8” and hammer the
inlet body section down with a soft-blow hammer
or block of wood. Once the body sections are
separated, raise the outlet section to clear the
disc pivot trunnions and place the outlet section
on a wooden skid.
7. Remove the pivot pin bushings (5) from the disc
pivot trunnions on 12” and larger valves. They
may be set in place with sealant so apply heat to
the disc trunnions with a propane torch to soften
the Loctite if necessary.
8. Thread an eye bolt into one of the threaded holes
in the disc’s rectangular pad. Using a nylon sling
through the disc trunnions and eye bolt, lift the
disc straight up while maintaining its 55 degree
tilt.
9. Place the disc on a wooden skid and using the
nylon sling through just the eye bolt, turn the disc
over with the disc ring (8) facing up.
All parts can now be easily inspected for wear or
damage and replacement parts can be ordered as
needed. If replacing the seat (10) or disc ring (8), it
is recommended that they be replaced as a set. The
pivot pins (4) should fit tightly in the body, but there
should be ample clearance (at least 1/32”) between
the pins (4) and the bushings (5).
REASSEMBLY OF BASIC VALVE
All parts must be clean and gasket surfaces should
be cleaned with a stiff wire brush in the direction of
the serrations or machine marks. Worn parts,
gaskets, and seals should be replaced during
reassembly.
1. Place the seat body half (2), with the inlet flange
face down on a wooden skid.
2. Install a lightly lubricated seat ring seal (11) in the
register of the seat body half.
3. Install the seat ring (10) with the serrated surface
toward the seal, into the register of the body seat
half.
4. With the disc on a wooden skid, and the disc ring
register up, place a lightly lubricated disc ring
seal (9) onto the disc register.
5. Assemble the disc ring with the serrated face
toward the seal.
6. Place a small amount of Loctite thread locking
compound on each of the retaining screws (12)
and thread them into the tapped holes in the disc.
Tighten them initially hand tight and then using
the cross-over tightening method, torque each
screw in graduated steps, according to the
following chart.
Valve Sizes Torque
12” to 14” 13 ft-lbs
16” to 24” 20 ft-lbs
30” 28 ft-lbs
36” and larger 40 ft-lbs
7. Thread in eye bolt into one of the threaded holes
in the disc’s rectangular pad. Insert a nylon sling
through the eye bolt and attach the loops of the
sling to the hook of a hoist. Carefully turn over
the disc, using the hoist, making sure that the
beveled seating surface of the disc ring does not
make contact with metal or hard surfaces.
8. Install the pivot pin bushings into the disc pivot
trunnions with Loctite 680.
9. Remove the nylon sling from the eye bolt and
place it through the disc’s pivot trunnions bores
and attach the loops of the sling to the hoist.
Attach a short chain from the hoist’s hook to the
eyebolt and adjust the length of the chain to keep
the disc at a 55 degree angle when housing the
disc.