For parts or assistance, call SHUR-DRI Customer Service at
1-800-535-4950
General Information
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 pressure. 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 pres-
sure 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
setting; 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 pres-
sure switch as shown. Tank and pressure switch cannot
be more than 10’ (3M) apart.
NOTICE:
Tank capacity is different than drawdown.
Tank capacity is the actual physical volume of the sheet
metal that makes up the tank.
OPERATING CYCLE
(FIGURE 2)
Step 1. Tank nearly empty – air expands filling area
above water cell (Figure A).
Step 2. Water enters tank – air is compressed above
water cell as it fills with water (Figure B).
Step 3. Pump-up cycle completed – air compressed to
OFF setting of pressure switch (Figure C).
Step 4. Water drawn from tank – compressed tank air
forces water out of water cell (Figure D).
Step 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 Stik
1
on male
threads of all threaded connections 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
equivilant drawdowns.
Hazardous voltage and hazardous pres-
sure. Disconnect all power to pump and bleed all pres-
sure 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