Dunkirk Q95M-200 Modulating Condensing Boiler - Manual (Page 10)

7 - NEAR BOILER PIPING
7.3 Safety Relief Valve / Temperature Pressure Gauge
WARNING
Burn and scald hazard. Safety relief valve could
discharge steam or hot water during operation.
Install discharge piping per these instructions.
!
Installation of (supplied) safety relief valve shall conform to
ANSI/ASME Boiler and Pressure Vessel Code, Section IV.
• Install furnished safety relief valve using 3/4” pipe
fittings provided with boiler. See Figure 2.
• Install safety relief valve with spindle in vertical
position.
• Do not install shutoff valve between boiler and safety
relief valve.
• Install discharge piping from safety relief valve. See
Figure 2.
• Use ¾” or larger pipe.
• Use pipe suitable for temperatures of 375°F (191°C) or
greater.
• Individual boiler discharge piping shall be independent
of other discharge piping.
• Size and arrange discharge piping to avoid reducing
safety relief valve relieving capacity below minimum
relief valve capacity stated on rating plate.
• Run pipe as short and straight as possible to location
protecting user from scalding.
• Install union, if used, close to safety relief valve outlet.
• Install elbow(s), if used, close to safety relief valve
outlet and downstream of union (if used).
• Terminate pipe with plain end (not threaded).
7.4 Expansion Tank & Make-up Water
• Determine required system fill pressure, system design
temperature, and system water content.
• Boiler contains 2.6 gallons (US). Size expansion tank
accordingly.
• Consult expansion tank manufacturer for proper sizing
information. Connect properly sized expansion tank
(not furnished) as shown in Figure 3 for diaphragm
type expansion tank.
• Adjust tank air pressure on diaphragm type expansion
tanks to match system fill pressure.
• Install air vent (furnished) as shown for diaphragm
type expansion tank system only.
• Install make-up water connections as show.
• If pressure reducing valve is used, adjust to match
system fill pressure.
• Verify clean water supply is available when connecting
cold make-up water supply to boiler.
• Use sand strainer at pump if water supply is from well
or pump.
GATE VALVE
REDUCED PRESSURE
BACKFLOW PREVENTER
FEED
WATER
PRESSURE
REDUCING VALVE
AIR SCOOP
DIAPHRAGM TYPE
EXPANSION TANK
SUPPLY PIPING
Check local codes
for maximum
distance from
floor.
FLOOR
Safety Relief Valve
Figure 2 - Safety Relief Valve Discharge Piping
Figure 3 - Diaphragm Type Expansion Tank Piping
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