Dunkirk 90-50 Installation, Operation & Maintenance Manual page 15

figure 5 - single Zone boiler piping
pressure relief Valve
The boiler is furnished with a factory installed relief valve in the top
of the boiler. Provide ¾" piping from the supplied relief valve to a
local floor drain, but leave an air gap between piping and drain. No
shutoff of any description shall be placed between safety relief valve
and the boiler, or on the discharge pipes between such safety valve
and the atmosphere. Installation of the safety relief valve shall con-
form to ANSI/ASME Boiler and Pressure Vessel Code, Section IV.
The manufacturer is not responsible for any water damage.
near boiler piping
expansion Tank and make-up Water
Determine required system fill pressure, system design temperature,
and system water content. Boiler contains 2.6 gallons (U.S.). Size
expansion tank accordingly. Consult expansion tank manufacturer
for proper sizing information. Connect properly sized expansion
tank (not furnished) as shown in Figure 6 for diaphragm type ex-
pansion tank and Figure 7 for conventional closed type expansion
tanks. For diaphragm type expansion tanks, adjust the tank air pres-
sure to match the system fill pressure. Install air vent (furnished)
as shown for diaphragm type expansion tank system only. Install
make-up water connections as shown per local codes. If a pressure
reducing valve is used, adjust to match the system fill pressure. In
connecting the cold make-up water supply to the boiler, make sure
that clean water supply is available. When the water supply is from a
well or pump, sand strainer should be installed at the pump.
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