19
19
3) Pressure Relief Valve (Required) - Limits the pressure in the tankless heater and piping. Use an ASME constructed
valve designed for domestic water service, such as the Watts #3L. Note that this is a pressure relief valve, not a T&P
valve. Select a valve with a pressure setting less than or equal to the working pressure marked on the tankless coil. Pipe
the discharge to a safe location using piping the same size as the discharge connection on the valve. In Massachusetts,
terminate the relief valve discharge pipe 12” above the floor.
4) Hose Bib Valves (Recommended) - These valves permit the coil to be periodically “backflushed” to remove sediment.
5) Globe or Ball Valve (Recommended) - Used to adjust the flow through the entire tankless heater system if needed.
6) Unions (Required) - Tankless heaters may require periodic gasket replacement or other maintenance which requires
removal of the heater from the boiler. Install unions anywhere in the tankless heater piping that will facilitate removal of
the heater.
7) Backflow Preventer (Required in Massachusetts) - If required by local codes, install a backflow preventer in the cold
water connection to the tankless coil just upstream of the piping shown in Figure 17. Install in accordance with local
codes and the backflow preventer’s installation instructions. Also install a potable water expansion tank on the outlet side
of the backflow preventer (between the backflow preventer and the piping shown in Figure 17).
WARNING
A mixing valve does not eliminate the risk of scalding.
•
Set the mixing valve and boiler low limit adjustments as low as possible.
•
Feel water before showering or bathing.
•
If anti-scald or anti-chill protection is required, use devices specifically designed for such service. Install
and maintain these devices in accordance with the manufacturer’s instructions. Do not use the mixing valve
as a substitute for pressure balancing valves or other devices required by plumbing codes to protect against
scalding.
FIGURE 17: TANKLESS HEATER PIPING
Содержание CWI103
Страница 2: ......
Страница 17: ...15 15 FIGURE 12 INDIRECT WATER HEATER BOILER SIDE PIPING FIGURE 11 STANDARD BOILER PIPING ...
Страница 19: ...17 17 FIGURE 15 BOILER PIPING WITH CHILLER FIGURE 14 ISOLATION OF BOILER FROM SYSTEM WITH A HEAT EXCHANGER ...
Страница 29: ...27 27 FIGURE 24a GAS VALVE DETAIL HONEYWELL VR8204 AND VR8304 FIGURE 24b GAS VALVE DETAIL ROBERTSHAW 7000DERHC ...
Страница 34: ...32 32 Notes ...
Страница 41: ...39 39 Notes ...
Страница 43: ...41 41 ...
Страница 45: ...43 43 ...
Страница 47: ...45 45 ...
Страница 49: ...47 47 FIGURE A1 BASE HEAT EXCHANGER FLUE COLLECTOR ASSEMBLY ...
Страница 51: ...49 49 FIGURE A2 JACKET INSTALLATION ...
Страница 53: ...51 51 FIGURE A3 TAPPING LOCATIONS SEE TEXT FOR TAPPING USES ...
Страница 54: ...52 52 Notes ...
Страница 55: ...53 53 Notes ...