GENERAL
Satisfactory
performance of the potable water system depends primarily on the design
and selection of the components of the pressure system. The system is
designed to store & deliver the correct amount of water at the optimum
pressure for normal and peak demands. Two 100% pumps are supplied such
that there is 100% standby capacity. During normal operation a single
pump will satisfy the demand and keep the tank charged with sufficient
pressure. At critical times of peak loading both pumps will operate. Pumps
will alternate and start as the pressure in the tank falls. If one pump
cannot maintain the flow/pressure, then the other pump will "kick-in".
Pump operation is controlled by pressure switches.
LOGIC
The pressure switches are located at the tank and the signals
from the pressure switches are sent to the control panel. The control
panel directs the pump operation. The first pressure switch is set at
a loss of 5 psi from the working pressure. This will cause one pump to
operate. The other pressure switch is set at 5 psi below the first pressure
switch. This will cause the second pump to turn on & operate in conjunction
with the first pump.
CONTROL
PANEL
NEMA (rating
as required) enclosure:
a.) Magnetic Motor Starter
b.) Motor Circuit Protector for each pump
c.) Pressure Switches for each pump
d.) Power "On" Light
e.) H.O.A. Switches for each starter
f.) Pump Run Lights
g.) Automatic Alternate
PUMPS
Pumps will be horizontal or vertical centrifugal. Pumps will be close
coupled with TEFC or "X" Proof Motors.
DISCHARGE
HEADER
A common pump discharge will be provided with gate & check valves. The
discharge from the filter will be a 150# flange for customer hook up.
TANK
The tank is a vertical ASME steel tank. Normally galvanized, it can be
painted as required. Tank will be pressure rated above the working pressure
and tested to 1.5 times working pressure. Tanks are fitted with a "heavy-duty"
Butyl Diaphragm.
SKID
A structural steel skid will be provided with the tank, pumps, control
panel, pipe, valves, and fittings installed. Unit will be factory tested
and fully operational. The skid will be blasted and coated with epoxy.
SUCTION
HEADER
A common 150# flange inlet will be provided for customer hook-up. Inlet
flow is divided to each pump suction.
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