Natco VW Installation And Operating Instructions Manual page 13

Flow Switch -
Factory Mounted
and Wired
Gas
Supply
Drain Valve
(See Note 2)
Available In Stage
Or Modulated Firing
NOTES:
1. All water connections 2" N.P.T. models.
2. Drain valve per ASME requirements.
3. A loop circulator is required to maintain forced circulation in the building hot water piping system.
Gas Supply
Flow Switch -
Factory Mounted
and Wired
NOTES:
1. All water connections 2" N.P.T. models.
2. Drain valve per ASME requirements.
3. A loop circulator is required to maintain forced circulation in the building hot water piping system.
To
Drain
Service Valves For
Heater Isolation
Cold Water
Supply
Building Loop
Figure 14 – Dual Installation Piping Diagram, Model IW
Drain Valve
(See Note 2)
Cold Water
Supply
Figure 15 – Single Installation Piping Diagram, Model IW
Model IW Water Heater
Service Valves For
Heater Isolation
To
Drain
Model IW Water Heater
Available In Stage
Or Modulated Firing
Service Valves For
Heater Isolation
*
Check Valve Building Loop
13
This Seqment Of Piping
*
Must Be Same Size As
Water Heater Connection
Building Loop
To Minimum
*
Pipe Size
1" Thru 850
1-1/4" 1010 Thru 1825
Building Loop
Circulator
(See Note 3)
To Building
Service
Connections
* This Seqment Of Piping
Must Be Same Size As
Water Heater
Connection
Check Valve
Building Loop
Circulator
(See Note 3)
To Building
Service
Connections