A.O. Smith ST1302 Manual page 17

Pump Motors
One way of visualizing the action is comparing
it to drinking from a straw. The partial vacuum
created when you suck on the straw causes the
drink to be forced up the straw by air pressure. If
the container from which you were attempting to
drink were sealed, liquid would not be drawn into
and up the straw.
Jet pump systems may be shallow well or deep
well. In shallow well systems the jet assembly is
located on the pump. In deep well systems the
jet assembly is located in the well, normally
below water level. If the water level falls more
than twenty-five below the jet during pumping or
draw down, the pumping action will slow and
eventually stop as the water level in the well con-
tinues to drop.
Convertible jet pumps may be configured for
either shallow or deep well applications.
Shallow well systems use one pipe into the
water source and deep well systems use two
pipes. One pipe provides water to operate the jet
and the second pipe carries water to the surface.
Systems known as packers are deep well systems
which use the well casing itself as one of the two
pipes.
A pitless adapter is a fitting which goes
through the well casing below the frost line. The
part inside the well has two pieces, with an O-
ring seal, which slide apart. A piece of pipe is
threaded into the top of the adapter so that the
movable part and the pipe or pipes extending to
the water may be removed. The use of a pitless
adapter allows the pipe or pipes going to the
pump to be buried below the frost line.
Level 2
15
LIFTPIPE
GROUND
LEVEL
FROSTLINE
PITLESS
ADAPTER
TO HOUSE
WATER LEVEL
CHECK (FOOT)
VALVE
PITLESS ADAPTER
A.O.Smith