Crown Boiler CWI207 ユーザーズマニュアル

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VIII System Piping
Standard Piping
Figure 11 shows typical boiler system connections on a single zone system.  Additional information on hydronic system
design may be found in Installation of Residential Hydronic Systems (Pub. #200) published by the Hydronics Institute in
Berkeley Heights, NJ.  The components in this system and their purposes are as follows:
1) Relief valve (Required) - Mount the relief valve on the right side of the boiler as shown in Figure 1 using the 3/4 nipples
and elbow provided.  The relief valve shipped with the boiler is set to open at 30 psi.  This valve may be replaced with one
having a pressure up to the “MAWP, WATER” shown on the rating plate.  If the valve is replaced, the replacement must
have a relief capacity in excess of the DOE heating capacity for the boiler.
Pipe the discharge of the relief valve to a location where water or steam will not create a hazard or cause property damage if
the valve opens.  The end of the discharge pipe must terminate in an unthreaded pipe.  If the relief valve discharge is not
piped to a drain it must terminate at least 6 inches above the floor.  Do not run relief valve discharge piping through an area
that is prone to freezing.  The termination of the relief valve discharge piping must be in an area where it is not likely to
become plugged by debris.
2) Circulator (Required) - Although the circulator is shipped on the boiler return, it can be installed on the boiler supply.  If
the circulator is moved to the supply, it should be positioned just downstream of the expansion tank as shown in Figure
11.
3) Expansion Tank (Required) - If this boiler is replacing an existing boiler with no other changes in the system, the old
expansion tank can generally be reused.  If the expansion tank must be replaced, consult the expansion tank
manufacturer’s literature for proper sizing.
4) Fill Valve (Required) - Either a manual or automatic fill valve may be used.  The ideal location for the fill is at the expansion
tank.
5) Automatic Air Vent (Required) - At least one automatic air vent is required.  Manual vents will usually be required in other
parts of the system to remove air during initial fill.
CAUTION
• INSTALL  BOILER  SO  THAT  THE  GAS  IGNITION  SYSTEM  COMPONENTS  ARE  PROTECTED  FROM
WATER  (DRIPPING,  SPRAYING,  RAIN,  ETC.)  DURING  APPLIANCE  OPERATION  AND  SERVICE
(CIRCULATOR  REPLACEMENT,  ETC.).
• OPERATION  OF  THIS  BOILER  WITH  CONTINUOUS  RETURN  TEMPERATURES  BELOW  120°F  CAN
CAUSE  SEVERE  HEAT  EXCHANGER  CORROSION  DAMAGE.
• OPERATION  OF  THIS  BOILER  IN  A  SYSTEM  HAVING  SIGNIFICANT  AMOUNTS  OF  DISSOLVED
OXYGEN  CAN  CAUSE  SEVERE  HEAT  EXCHANGER  CORROSION  DAMAGE.
• DO  NOT  USE  TOXIC  ADDITIVES,  SUCH  AS  AUTOMOTIVE  ANTIFREEZE,  IN  A  HYDRONIC  SYSTEM.
DANGER
PIPE  RELIEF  VALVE  DISCHARGE  TO  A  SAFE  LOCATION.
DO  NOT  INSTALL  A  VALVE  IN  THE  RELIEF  VALVE  DISCHARGE  LINE.
DO  NOT  MOVE  RELIEF  VALVE  FROM  FACTORY  LOCATION.
DO  NOT  PLUG  RELIEF  VALVE  DISCHARGE.