Pentair MYERS HJ Série Notice D'utilisation page 4

Introduction
Major Components and What They Do
Tank and Air Volume Control
The tank serves two functions: (1) it provides a reservoir
of water – some of which can be drawn through the
house fixture before the pump must start; (2) it maintains
a cushion of air under pressure.
When a Pre-charged Bladder Tank is used, no air
volume control is needed. This tank contains an isolated
pre-charge of air.
When a non-bladder type tank is used, an air volume
control adds air to the tank as needed. The air volume
control is hooked to the side of the tank and a pressure
tube is connected from the air volume control to the
suction side of the pump.
Pressure Switch
A pressure switch is provided for automatic operation.
The pump starts when the system pressure drops to the
cut-in pressure and stops when system pressure reaches
the cut-out pressure.
Impeller, Jet and Pressure Regulator
The pump impeller rotates with the motor shaft, causing
an increase in pressure. The rotation of the impeller
creates a vacuum, allowing water to be drawn into the
pump. Part of the water is diverted back to the jet, where
it again passes through the nozzle and venturi, creating
additional vacuum to draw in more water and deliver it
at high pressure to the impeller.
In a deep well installation, the jet assembly is submerged
in the well because the vertical distance to the water
level exceeds the suction lift of the pump. Adjustment of
the regulator causes the correct amount of water to be
diverted back to the jet for the most efficient operation.
The regulator may be used to restrict the flow of water
in a shallow well system if the convertible pump has the
capacity to draw more water than the well can produce.
In a shallow well installation, the jet assembly is
attached directly to the pump because a vacuum will lift
water to the pump.
Well Water Level
Shallow well water systems are recommended for use
in wells where the sum of: (1) the vertical measurement
from the pump to the water level in the well; (2) the well
water drawdown; and (3) the suction pipe friction in feet
equals 25 feet or less.
Location
The unit may be installed in any convenient location to
the well that provides sufficient space for installation and
servicing the well. A dry basement, pit or utility room is
an excellent choice when allowed by law. Check with
state and local agencies to determine restrictions in your
area.
Wells
A new well should be sand-pumped until clear before
installation. Sand will damage pump parts and the seal.
The drawdown level of the well should not exceed the
maximum rated depth for the pump or the capacity will
be reduced and may cause loss of prime.
NOTICE Chlorinating the well may be required before
installing a new pump. Check with local health
department for recommendations.
Piping
Plastic pipe is shown in the illustrations. Galvanized iron
pipe can be used if desired.
• The piping must be clean and free of all foreign
matter to prevent clogging of the jet.
• If the unit is installed offset from the well, the piping
should slope upward from the well to the pump.
Unions should be provided where necessary.
• Provide a drain cock at a low point in the service
line to drain the pressure tank.
Be sure all suction connections are airtight. The primary
cause of problems in a new installation is air leaks in
one or more joints in the suction line.
Sealing Pipe Joints
Use only PTFE pipe thread sealant tape or PTFE-based
joint compounds for making all threaded connections
to the pump itself. Do not use pipe joint compounds
on plastic pumps: they can react with the plastic in
pump components. Make sure that all pipe joints in
the suction pipe are air tight as well as water tight. If
the suction pipe can suck air, the pump will not be
able to pull water from the well.
4