3
pattern in graduated steps. If leakage occurs
wait 24 hours and re-torque the bolts but do not
compress the gasket more than 50% or exceed
bolt maximum torque rating.
VALVE CONSTRUCTION
The standard Figure 925 Sewage Air Release
Valve has a cast iron body, stainless steel float
and linkage mechanism and a rubber seat.
Optional materials such as ductile iron body can
be provided for higher working pressures. Refer
to the List of Materials submitted for the order if
non-standard materials were provided.
Refer to Page 5 for details of construction and
parts location.
The Figure 925 has a 10 to 150 PSI working
pressure range while the Figure 925L has a 10
to 75 PSI working pressure range.
The valve has an inlet connection at the bottom
where the valve attaches to the system and a
smaller outlet connection at the top through
which air leaves the valve.
WARNING
Removing the valve from the line or
disassembling the valve while there is pressure
in the valve body may result in injury or damage
to the valve
PREVENTIVE MAINTENANCE
Figure 925 Sewage Air Release Valves require
no scheduled lubrication or adjustment.
A periodic visual inspection should be performed
to ensure the outlet piping is not obstructed and
to verify there is no fluid leakage.
Depending on the nature of the fluid, sewage air
valves may become clogged with sediment or
grease and require periodic cleaning. To
facilitate such cleaning VAG/GA Industries air
valves with
an “F” at the end of the Figure
Number (e.g., 925F, 925LF) were supplied with
“backflushing attachments.” Refer to the
backflushing instructions on Page 4 of this
manual for additional information.
TESTING
Valve operation can be easily tested. Close the
inlet isolation valve and remove or loosen the
pipe plug nearest the inlet to drain the water
from the valve. The float should drop as the
water leaves the valve. NOTE: A manual valve
can be installed in place of the pipe plug to
facilitate testing (valves are included with
backflushing attachments).
Replace or tighten the pipe plug and slowly open
the inlet isolating valve. After expelling air, the
valve should close and seal tightly.
TROUBLESHOOTING
•
Valve Does Not Close / Fluid Leakage
Verify debris has not collected on the seat
preventing tight closure
Verify rubber orifice button and/or orifice
seating surfaces are not damaged
Verify float has buoyancy
Verify linkage mechanism operates freely
without binding or sticking
Verify the pressure at the valve inlet it at
least 10 PSI
•
Valve Does Not Open
Verify debris in the valve is not
preventing the float from freely falling
when fluid is drained from valve
Verify linkage mechanism operates freely
without binding or sticking
Verify the pressure at the valve inlet does
not exceed the valve
’s maximum working
pressure
DISASSEMBLY
While small valves may be more easily serviced
by removing it from the line, all valves can be
serviced while the body remains connected to
the pipeline. A skilled technician with proper
tools should perform all work. No special tools
are required.
Disassemble the valve only as far as needed to
replace damaged or worn parts.
First ensure there is no pressure within the
valve. Remove the cover bolts (16) and lift off
cover (2) with float and linkage attached. It may
be necessary to pry the cover off. Be careful not
to damage or lose the O-ring (10) unless it
’s
being replaced.
Remove the two spring pins (13) connecting the
lever arm (11) and float arm (12) to the bracket
