PIPE THE BOILER
3. PIPE THE BOILER
A.PREPARATION
1.Make sure the boiler has been pressure tested as outlined in “Place the Boiler Sections” in this manual.
2.The Supply and Return piping can be installed before installing the jacket. Use nipples long enough to extend through the jacket.
3.Install a pipe plug or nipple and cap in the 3” tapping in the top of the tapped intermediate section when necessary. Use only the lower side connection, required for return piping as shown.
B.SUPPLY AND RETURN PIPING
1.Always locate the Supply and Return connections as shown in Figure 3.1 and other illustrations in this manual.
2.The suggested supply and return sizing in Table 3.1 and in the “Boiler Ratings and Dimensions” section in this manual is based on a flow rate through the boiler equivalent to a 20°F temperature rise (1 gpm flow for each 10,000 Btu/Hr of boiler output). Using higher flow rates is not recommended. This could cause poor water flow distribution in the boiler.
Lower flow rates (higher temperature rise) are acceptable provided the return temperature to the boiler is at least 130°F on gas boilers and 150°F on oil boilers to prevent condensation of flue gases.
3.Do not reduce the number or size of supply and return connections given in Table 3.1. These are required to control the flow velocities in the boiler and maintain uniform distribution.
4.When the boiler is connected to heating coils located in air handling units, the boiler piping system must be equipped with flow control valves or other automatic devices to prevent gravity circulation of the boiler water during the cooling cycle.
C. LOW SYSTEM TEMPERATURE
1.Low Return Temperature Piping, General
a)When the return temperature from the system will be below 130°F on gas boilers or 150°F on oil boilers for extended periods (heat pump systems, outdoor reset, snow melt, etc.), provide piping and controls to protect the boiler from condensation. Condensation will damage the boiler and will lead to shortened boiler life and maintenance problems.
Figure 3.1: Piping Detail, Supply and Return Connections
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