3
GENERAL INFORMATION
Tanks listed below are pre-charged, or filled with air at the
factory, to 40 pounds per square inch (PSI) (276kPa). When
installing tank, set tank pressure according to Chart 1. To do
this, bleed air from or add air to tank through valve on top of
tank.
NOTICE:
Always set or check tank pre-charge with NO WATER
in tank or water pressure in system. If you have already
pumped water before setting or checking pre-charge pressure,
turn pump off. Open faucet until there is no more water pres-
sure. Set pre-charge in tank according to Chart 1, then close
faucet and turn pump back on.
NOTICE:
Replace and tighten air valve cap after pressure is
adjusted correctly. Failure to replace air cap may allow loss
of air pressure and lead to tank waterlogging and water cell
failure.
CHART I
(The first number on the pressure switch is the pump on set-
ting; the second number is the pump off setting.)
Pre-charged storage tanks can be connected together to
increase the drawdown. Drawdown is the actual amount of
usable water available from when the tank is full to when the
pump turns on. Installing two tanks of same size will double
the drawdown supply, three tanks will triple the drawdown
supply, (Figure 1). Locate pressure switch as shown. Tank and
pressure switch cannot be more than 10’ (3M) apart.
NOTICE:
Tank capacity is different than drawdown. Tank capac-
ity is the actual physical volume of the sheet metal that
makes up the tank.
OPERATING CYCLE (FIGURE 2)
1. Tank nearly empty – air expands filling area above water
cell (Figure A).
2. Water enters tank – air is compressed above water cell as
it fills with water (Figure B).
3. Pump-up cycle completed – air compressed to OFF setting
of pressure switch (Figure C).
4. Water drawn from tank – compressed tank air forces water
out of water cell (Figure D).
5. Water cell empty – new cycle ready to begin (Figure A).
Connect discharge pipe from pump to a tee. Connect one side
of tee to tank flange and the other side of tee to service. Use
plastic or steel pipe as required. To prevent leaks, use Teflon
tape or Plasto-Joint Stik1 on male threads of all threaded con-
nections to tank.
STANDARD TANK REPLACEMENT
When replacing standard tank in a water system with pre-
charged tank, no bleeder orifices or Air Volume Control (AVC)
are required. When sizing a pre-charged tank to replace a
standard tank, the tanks should have equivalent drawdowns.
Hazardous voltage and hazardous pressure.
Disconnect all power to pump and bleed all pressure from
system before working on pump, tank, or piping.
1
Lake Chemical Co., Chicago, Illinois
When Pressure Switch
Reduce Tank
Setting Is
Precharge (PSI) To
20-40 PSI (138-276 kPa)
18 (124 kPa)
30-50 PSI (207-345 kPa)
28 (193 kPa)
40-60 PSI (276-414 kPa)
38 (262 kPa)
To service
From well
Tanks
Pressure
switch
Figure 1
Figure 2
WATER
A
B
WATER
WATER
C
D
