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STP SERIES Install, Operation, and Maintenance Manual
SECTION 3: OPERATION AND CONTROLS
Rev-1
Diversified Heat Transfer, Inc.
•
439 Main Road, Route 202
•
Towaco, New Jersey 07082
Page
19
of
97
STP Manual
PHONE: 800-221-1522
•
WEBSITE: www.dhtnet.com
09/11/2019
controller, depending upon the reading from the temperature sensor on the domestic hot
water outlet of the heat exchanger. Unit employs closed loop feedback control system to
maintain target temperature set point in tight range. Boiler or HTHW exits through the outlet
connection on the bottom of the heat exchanger as shown. Flow rate of heating medium is
modulated to maintain the desired set point in varying load conditions.
Variety of heat exchanger and storage tank sizes are available to satisfy wide range of domestic
hot water application requirements. Standard storage tanks are available in carbon steel with
double glass lining or optional duplex stainless steel materials of construction. Carbon steel tank
configuration also includes consumable anodes or optional powered anodes for maintenance
free operation by preventing corrosion of the tank. Diverter tubes (also called dispersion tubes)
are installed inside storage tank on both cold and hot water inlet connections which helps to
prevent mixing of hot and cold domestic water. STP Series units can be used with both
condensing and non-condensing boilers for combination space and domestic water heating.
STP series units are also available with optional simple Aquastat controls which enable/disable
the constant speed domestic circulators and boiler through relay panel in order to maintain the
domestic hot water temperature inside storage tank.
FIGURE 3-1a: STP Series with Simplex Heat Exchanger Configuration
T&P RELIEF VALVE
ADJUSTABLE
RELIEF VALVE
DRAIN VALVE
ISOLATION VALVE
BRAZED PLATE
HEAT EXCHANGER
ANODE
HOT WATER OUTLET
CIRCULATION PUMP
INSULATED
STORAGE TANK
LIFTING LUGS
CONTROL
PANEL
TEMP SENSOR OR
AQUASTAT
CLEANING PORT
ANODE