Rheem 136-1826 - Manual (Page 24)

* PIPING MUST BE EQUAL BETWEEN TEES AND TANKS.
NOTES:
1. Plumb all swing check valves in gravity closed position.
2. Minimum pipe size equal to heater inlet/outlet connection size (between heater and tanks).
3. Pipe sizes between tanks are to be based on estimated GPM flow rates (Max. 10 FPS Vel.)
4. Pipe all relief valves to drain or as local codes require.
5. Duplex manifold kit & 115 gallon jacketed and insulated storage tanks available from factory.
Fig. # 8067-RHEEM
24
PIPING DIAGRAM-1 HEATER 3 TANK