Dunkirk Q90-200 Series II - Manual (Page 9)

9
Expansion Tank And Make-Up Water
• Determine required system fill pressure, design
temperature, and 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)
See Figure 3, for diaphragm type expansion tank.
For diaphragm type expansion tanks, adjust tank air
pressure to match system fill pressure.
• Install air vent (furnished) as shown for diaphragm type
expansion tank system only.
• Install make-up water connections as shown and per
local codes.
• 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. When water supply is from well or pump,
install sand strainer at pump.
WARNING
Burn and scald hazard. Safety relief valve could
discharge steam or hot water during operation.
Install discharge piping per these instructions.
!
Safety Relief Valve / Temperature Pressure Gauge
Boiler is furnished with safety relief valve and temperature
pressure gauge.
• Install safety relief valve using pipe fittings provided
with boiler. 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.
A. Use ¾” or larger pipe.
B. Use pipe suitable for temperatures of 375°F
(191°C) or greater.
C. Individual boiler discharge piping shall be
independent of other discharge piping.
D. Size and arrange discharge piping to avoid
reducing safety relief valve relieving capacity below
minimum relief valve capacity stated on rating
plate.
E. Run pipe as short and straight as possible to
location protecting user from scalding and properly
drain piping.
F. Install union, if used, close to safety relief valve
outlet.
G. Install elbow(s), if used, close to safety relief valve
outlet and downstream of union (if used).
H. Terminate pipe with plain end (not threaded).
4 - NEAR BOILER PIPING
Figure 3 - Relief Valve Discharge Piping
Check local codes
for maximum
distance from
floor or other
allowable safe
point of discharge
RELIEF VALVE
DISCHARGE
PIPING