Introduction
Operation
Step 1.
Service Cycle
In the service cycle, raw water enters the inlet port of the media tank. The oxidation process begins.
This air/water contact oxidizes the iron and hydrogen sulfide in the water. Oxidized iron particles
are trapped by the filter bed as the water passes through. Filtered water enters the lower distributor
and travels up the distributor tube to the outlet port on the filter valve.
Step 2.
Aeration Operation Air Recharge Cycle
When energized, the air pump sends air through the solenoid valve into one end of the shuttle valve.
Once air pressure in the shuttle valve is greater than the water supply pressure at the other end of the
shuttle valve, the piston shifts to the open position. In the open position, the bleed-off port discharges
excess water and old air to the drain port through a flow restrictor. Simultaneously, the air inlet port
opens to provide a direct connection between the air pump and the top of the media tank. The air
pump runs for a preset period of time recharging the head of air in the media tank.
Air Recharge Shut Off
The timer turns power off to the air pump and the solenoid valve at the end of the recharge cycle. The
solenoid valve then closes the port between the air pump and the shuttle valve. The port between the
shuttle valve and the atmosphere opens and releases air pressure. This allows water pressure to shift
the piston to the closed position. With the piston in the closed position, the air recharge inlet port is
closed and direct communication between the bleed off tube and the drain port is also closed.
Timer Operation
A timer controls the air recharge cycle and how frequently it occurs. The timer simultaneously
energizes the air pump and the solenoid valve. After a preset amount of time, the timer shuts off the
air pump and de-energizes the solenoid valve.
Solenoid Valve Operation
The solenoid valve is a three-way valve having ports that connect to the air pump, shuttle valve and
the atmosphere. In the service cycle, the solenoid valve is de-energized and closes the port to the
air pump, providing a positive shut-off to the pump. This prevents water from backing up into the air
pump and damaging the pump. In the air recharge cycle, the solenoid valve closes the port to the
atmosphere and opens the port from the air pump.
Shuttle Valve Operation
In the service position, water pressure holds the shuttle valve piston in the closed position, trapping the
airhead in the media tank and closes the air recharge inlet port and drain port. During air recharge
cycle, air pressure is greater than the water pressure and forces the shuttle valve piston in the open
piston. The shuttle valve has an internal pressure relief valve that will relieve pressure (greater than
100 psi) that may build up in the media tank. This precautionary function protects components from
failure due to excessive pressure.
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