INSTALLATION, OPERATION and
MAINTENANCE
Silent Check Valves
INTRODUCTION
This manual will provide the information to
properly install, operate and maintain the valve
to ensure a long service life. GA Industries
Silent Check Valves are ruggedly constructed to
provide years of trouble-free operation with
minimal maintenance.
These Silent Check Valves are not intended for
use with fluids containing suspended solids such
as wastewater and sewage. There are other
types of GA Industries check valves that are
suitable for such applications.
CAUTION
The valve is NOT recommended for use with
compressed air or other gases.
CAUTION
Silent Check Valves are not intended for used
with hazardous, flammable or toxic fluids.
The Shop Order (SO) Number, Figure Number,
size and pressure rating are stamped on a
nameplate attached to the valve. Please refer to
the SO number when ordering parts.
DESCRIPTION OF OPERATION
GA Industries Silent Check Valves are designed
to open fully to allow forward flow and close
quickly to prevent reverse flow. While typically
installed on the discharge of water pumps, they
can be used elsewhere in piping systems to
prevent reverse flow.
On pump startup, water enters the valve from,
the seat end and pushes the disc away from the
seat and compresses the spring.
Upon pump shutdown, the spring rapidly de-
compresses and quickly pushes the disc back to
the seat to close the valve. This rapid closure
occurs before the reversing flow can slam the
valve shut, thereby preventing water hammer.
The valve disc and the compression spring
behind it are the only moving parts.
RECEIVING AND STORAGE
Inspect the valve upon receipt for damage
during shipment. Carefully unload all valves to
the ground without dropping.
The valves should remain in a clean, dry and
weather protected area until installed. For long
term storage (greater than 6 months) the rubber
surfaces of the seat should be coated with a
non-toxic lubricant such as "SuperLube" made
by Synco Chemical. Do not expose the rubber
parts to sunlight or ozone.
VALVE CONSTRUCTION
GA Industries silent check valves are available
in two styles.
Globe Style: The globe style valve body has
integral flanges. Figure 280-D is supplied
with flanges that are faced and drilled per
ANSI B16.1 Class 125 while Figure 280-U
has flanges per ANSI B16.1 Class 250.
Wafer Style: The wafer style valve has a
compact body designed to be clamped
between two flanges. Figure 290-U can be
installed between ANSI Class 125 or Class
250 flanges while the Figure 290-D can only
be installed between ANSI Class 125 flanges.
Both styles have an iron body and either bronze
or stainless-steel internal metal components.
The valve seals drop tight when the plug mates
with a replaceable rubber O-ring retained in a
dove-tail groove in the seat. The seat in Figure
280 globe style valves is retained in the body by
screws for transportation and installation in the
pipeline. However, once installed, the seat is
retained by the mating flange. Do not remove
the
upstream
piping/flange
while
the
downstream system is pressurized, or the seat
may be dislodged from the body. The seat in
wafer style Figure 290 valves is threaded into
the body so no screws are used. Refer to Page
4 for details of construction and parts location.
