IBC Sl Series Installation & Operating Manual page 49

No isolation valve permitted between boiler and relief valve
Microbubble air eliminators are best installed where the fluid is at the highest
temperature and lowest pressure.
Expansion tank connection (point of no pressure change) should be on the suction side
of the circulator, with minimal pressure drop between.
Fill station with isolation valve closed, or fill tank.
Dirt separator recommended
Figure 33 Basic boiler trim options
Fluid fill is most often accomplished by using a boiler regulator and fill valve set at 12 psig or
more, with the appropriate backflow prevention device as required by local code. This is
acceptable in areas where municipal water or well water has been treated and filtered to remove
excessive minerals and sediment, and water chemistry is known to be suitable for closed loop
hydronic systems. In areas where water quality is in question, or when chemical treatment or
glycol is required, other options should be considered. Follow the applicable codes and good
piping practice.
Warning
Close the fill valve after any addition of water to the system, to reduce risk of water
escaping.
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3.11.2 System piping