Val-Matic 14 and Larger Wafer and Lug Style Dual Disc Check Valve - Manual (Page 2)

14”-60” WAFER STYLE DUAL DISC
®
CHECK VALVE
OPERATION, MAINTENANCE AND INSTALLATION
INTRODUCTION
This manual will provide you with the information to
properly install and maintain the valve to ensure a
long service life. The Dual Disc
®
Check Valve is
ruggedly constructed with bronze or stainless steel
trim to give years of trouble free operation. The
valve should be installed in horizontal or vertical flow
up pipes carrying clean water. The valves can be
equipped with special springs for operation in blower
air service (Series 8900).
The Dual Disc
®
Check Valve is designed to open
fully to provide flow in the forward direction and
close rapidly upon flow reversal. The valves are
used to prevent reverse flow through pumps or in
piping systems. The size, cold working pressure,
and model number are stamped on the nameplate
for reference.
This valve is not intended for fluids containing
suspended solids such as wastewater. For
wastewater and other high turbidity applications, use
Val-Matic Series 500 Swing-Flex
® Check Valves.
1
RECEIVING AND STORAGE
Inspect valves upon receipt for damage in shipment.
Unload all valves carefully to the ground without
dropping. When lifting, the valve should be secured
by the body and never lifted by the bronze or
stainless steel trim. Threaded holes are provided on
the top of the valves for the insertion of an eye bolt.
The valves should remain crated, clean and dry until
installed to prevent weather related damage. For
long term storage greater than six months, the
rubber surfaces of the seat (when provided) should
be coated with a thin film of FDA approved grease
such as Lubriko #CW-606. Do not expose rubber
seat to sunlight or ozone for any extended period.
FIGURE 1. DUAL DISC
®
CHECK VALVE
DESCRIPTION OF OPERATION
The Dual Disc
®
Check Valve is designed to prevent
reverse flow automatically. On pump start-up, the
flow of water enters the valve from the seat end
(right side in Figure 1) and forces the two discs open
until they strike the disc stop pin. On pump shut-
down, the torsion spring closes the disc before a
flow reversal takes place.
The valve body is supplied with either compact
wafer ends as shown in Figure 1 for installation
between mating flanges or in a lug wafer
configuration where the flanges are tapped to accept
flange bolts.
The only moving parts in the valve are the discs and
spring. The discs and spring are guided in the body
with a hinge pin and a full open disc stop pin. The
pins are restrained in the body by stabilization
spheres to prevent vibration. The valve also has a
resilient seat for drop tight shut off.
CAUTION: This valve is not intended for
fluids containing suspended
solids or hazardous fluids.