Single Tank During Backwash; Dual Tank Normal Filtration; Dual Tank During Backwash; Face Piping Installation - Pentair THS Series Installation And User Manual

1.3 Single Tank During Backwash

During backwash mode, both of the
diaphragm valves are actuated. Since
water cannot enter the tank through
the influent piping, it enters through the
effluent piping. The water is pushed
up through the sand bed, which is
called "Fluidizing" the sand bed. This
loosens dirt and debris trapped by the
sand. This debris is then passed
through the influent piping and exits
through a waste pipe connected to the
valve.

1.4 Dual Tank Normal Filtration

During normal filtration in a dual tank
system, water is split between the two
tanks. It passes through the influent
piping and then through the sand beds.
It is then passed through the collection
laterals at the bottom of the tanks and
passed out of the effluent piping and
returned to the pool.

1.5 Dual Tank During Backwash

During backwash mode in a dual tank
system, one of the three way valves and
the two-way valve are actuated
simultaneously. This allows water to pass
through one of the filters as if it were
filtering normally. When the water exits
that tank, it is forced to enter the second
tank through the effluent pipe. This water
then backwashes the second tank. The
dirt and debris is then passed through the
influent pipe of tank two and out of a waste
pipe connected to the valve.

2 Face piping installation

Diaphragm Valve Face Piping Kit Installation Manual
5/31/12
Pg. 3 of 52
Rev. F