Water - Lochinvar Power-Fin Designer's Manual

Designer's Guide / Power-fin Water Heater
Chapter 4 – Water
Domestic water pipe design seems easy enough. The Power-fin water heater is connected to a
storage tank. Water recirculates between the two to maintain a prescribed water temperature.
Hot water is drawn off the top of the tank to supply the system. Fresh water flows in from the city.
The Power-fin fires again to maintain the temperature of the system.
However, there are other concerns, other details
regarding the system design that we must check to
provide the water heater with safe and comfortable
operating conditions. There are temperature and water
capacity demands, water chemistry and multiple unit
piping and many more.
Here is a short list of important details to keep in mind as
we design our system.
IMPORTANT BULLET POINTS FOR WATER PIPING
1. Water Connections
All models have 2 1/2 inch copper sweat pipe inlet and outlet connections.
Installed piping to and from the tank must be a minimum of 2 1/2 inch diameter.
2. Maximum Flow Rate
The Power-Fin 502-1302 models have a specified flow rate of 75 GPM.
The Power-Fin 1501-2001 models have a specified flow rate of 90 GPM.
3. Working Pressure
The appliance should not be operated at less than 12 PSIG.
4. Minimum Inlet Water Temperature
The minimum inlet water temperature returned to the appliance is 140°F (60°C).
5. Flow Rate
The appliance requires a constant flow rate through the heat exchanger. Do not vary
the flow rate through the water heater during a call for heat.
6. Unions and Ball Valves
The water piping
of the water heater to isolate the unit for service and flow adjustment. Use only full port
ball valves.
SINGLE HEATER / SINGLE TANK
The most common design is for a single water heater
piped to a single tank. The water flows from the water
heater into the tank and then back from the tank to the
heater. A factory supplied circulation pump creates
the flow in this water heater loop only.
A system loop carries hot water away from the tank
and the building return line is connected to the water
heater loop. A field supplied circulation pump will
create the flow in the system loop.
to the tank should have unions and ball valves at the inlet and outlet
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LOCHINVAR CORPORATION
300 MADDOX SIMPSON PKWY
LEBANON, TN 37090
www.lochinvar.com

Water

Reference Drawing A1 – Page 37