9
IOM D-040
3. OPERATION
The D-040 series Combination Air Valve has the features of both an air release valve and an air & vacuum valve. The
air release component is designed to automatically release small pockets of air to the atmosphere as they
accumulate along a pipeline or piping system when it is full and operating under pressure. The air & vacuum
component is designed to automatically discharge or admit large volumes of air during the filling or draining of a
pipeline or piping system. This valve will open to relieve negative pressures whenever water column separation
occurs.
4.
TROUBLE SHOOTING
PROBLEM
REASON
SOLUTION
Discharge Outlet is broken. Valve was hit or mishandled. Easy to replace: gently pry off the outlet with screwdriver
Pressure insert the replacement part using a plastic
hammer. Replacement part can be ordered from A.R.I.
Note: The part is not mandatory for the function of the
valve.
Outlet thread size needed
in order to attach a vent/
drain pipe
End user needs to connect a
vent/drain pipe from the
discharge outlet.
1" D-
040 has 3/8” female thread.
2” D
-
040 has 1¼” female thread.
End of pipe must be left open in order for valve to
function.
Valve spits water.
This is normal at start up
and during pressure test.
Could be debris stuck to the
sealing mechanism.
Perform steps for
BASIC MAINTENANCE
Valve is continuously
leaking.
Line pressure issues
(inadequate pressure) or
debris lodged in seal or O-
rings.
Check line pressure. It needs at least 0.2bar (3 psi) to seal
tight.
Is the valve on a booster pump? Can be an installation
issue if the valve is level with the water level in a tank -
there is no pressure to seal.
Perform steps for
BASIC MAINTENANCE
Valve leaks from threads.
Damaged O-ring
Plastic threads stripped.
Replace the Base O-ring
Check for cross-threading. Replace Base.
Offer to replace with a metal Base.
