State 520 - Manual (Page 32)

Applications
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Page
‐Dual‐purpose hot water heating‐
(Domestic and Space Heating):
* The circulation pump is to provide no less than 2 GPM and no more than 4 GPM through each activated
water heater unit in the system.
 Priority Control Devices such as a flow switch, an Aquastat or other electronic
controller can be used to prioritize the domestic water system over the heating
system.
 Follow all local codes, or in the absence of local codes, follow the most recent
edition of the National Standard Code, ANSI Z21.10.3.
 This illustration is a concept design only. The reference to the 1/8 th hole in check
is only for the State of Massachusetts. There are a wide variety of variations to
the application of controls and equipment presented. Designers must add all
necessary safety and auxiliary equipment to conform to code requirements and
design practice. For more details, contact the manufacturer.
WARNING
Takagi
P
T
An approved Pressure Only
Relief Valve, Tie to Location
approved by Local Codes and
Must Meet BTU Rating of Takagi
Model Used
Unions
4" Gas Exhaust Vent (Discharge
Must Comply with Local and
State Codes). Can Not Be
Common Vented with Other
Appliances
Atmospheric
Vacuum Breaker
Pump (Must Be Sized Properly
With Each Application). Pump
Shall Run 60 Seconds Every 6
Hours
Pressure
Gauge
Apply Correct
Thermal
Expansion
Tank-Size Per
Application
Tempered
Water To
House
Cold Inlet
Shut-Off
Valve
Check Valve Will
Have 1/8" Hole in
Check, As Per
Mass. Code
Thermometer
Thermostatic Mixing Valve
Shut-Off
Valves
Check Valve
Hot
Water
Outlet
Cold
Water
Inlet
T-Handle Gas
Shut-Off Valve
**Maximum allowable distance of
50-Ft. from water heater and
heating panel
Heating Coil
(used with air-handler)
Diagramatic Layout of Radiant Heating and
Domestic Water Heater Per Mass. Code
Thermometer
Check
Valves
Gas
Inlet
Drain
Plug Water
Filter
120 VAC Switch or Outlet
An approved Pressure Only Relied
Valve, Tie to Location approved By
Local Codes and Must Meet BTU
Rating of water heater Model Used