MYERS Pentair Water, Owner'S Manual

Page: 3 / 8

Installation 3
INSTALLATION
The tanks listed below are pre-charged, or filled with air
at the factory, as shown under “Product Information –
Pre-Charged Tanks,” below. When installing tank or if
drawdown decreases significantly, check as follows:
To check air charge in tank
1. Shut off electric power to pump, open faucet near
tank, and drain completely.
2. At air valve, unscrew air valve protective cap and
check tank air pressure with tire gauge. See Chart 1
for the correct pressure setting. If needed, adjust the
tank pressure up or down. To do this, bleed air from
or add air to tank through valve on top of tank.
3. Use soap or liquid detergent to check for air leaks
around air valve. Continuous bubbling indicates leak.
If necessary, release air pressure and install new core
in air valve (same as used for automobile tubeless
tires.)
NOTICE: Always set or check tank pre-charge with NO
WATER in tank and no water pressure in system. If you
have already pumped water before setting or checking
the pre-charge pressure, turn the pump off.
NOTICE: Replace and tighten air valve protective cap
after pressure is adjusted correctly. Failure to replace cap
may allow loss of air pressure and lead to tank waterlog-
ging and diaphragm failure.
Chart I
(The first number on the pressure switch is the pump
“ON” setting; the second number is the pump “OFF”
setting.)
This tank is designed to be supported by the system pip-
ing either directly above the pump or in a convenient
location in the piping system as close to the pump as
possible.
NOTICE:
Tank capacity is different than drawdown. Tank
capacity is the actual physical volume of the sheet metal
that makes up the tank.
STANDARD TANK REPLACEMENT
When replacing a standard tank in a water system with a
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.
When Pressure Switch Adjust Tank
Setting Is Precharge (PSI) To
20-40 PSI (138-276kPa) 18 (124kPa)
30-50 PSI (207-345kPa) 28 (193kPa)
Product Information – Pre-Charged Tanks
3820 1100
Air Valve
Protective
Cap
Air Valve
Figure 1: Air valve and protective cap.
Equivalent
Drawdown - Gals (L)
Maximum to Standard Tank Tank Tank Pre-Charge
Catalog Capacity Tank
20-40 PSI 30-50 PSI Maximum
Diameter Height Discharge Pressure
Number US Gals (L) (US Gals) (L) (138-276kPa) (207-345kPa) Water Temp in. (mm) in. (mm) Tapping PSI (kPa)
MIL2 2 (7.6) 6 (23) 0.7 (2.7) 0.6 (2.3) 210°F (99°C) 8.4" (213) 12.6" (319) 3/4" 20–22
MIL5 5 (19) 15 (58) 1.8 (6.8) 1.5 (5.7) 210°F (99°C) 10.6" (270) 16.2" (411) 3/4" (138–152)