HTP EL-80 - Page 21

LP-293 Rev. 9.24.15
21
NOTES:
1. This drawing is meant to show system piping concept only.
2. A mixing valve is recommended if the DHW temperature is set above 119
o
F.
3. Install a minimum of 12 diameters of straight pipe upstream of all circulators.
4. Piping shown is Primary/Secondary.
5. System ow (secondary loop) should be greater than the boiler primary loop ow. In all cases, the boiler primary loop ow rate must be
maintained above the minimum ow rates published in this manual.
6. Installations must comply with all local codes.
7. In Massachusetts, a vacuum relief valve must be installed in the cold water line per 248 CMR.
8. Reference Figure 6 to determine manifold pipe sizing.
The piping will not support the weight of the circulators. Refer to the circulator manufacturer’s instructions to properly support
the circulator. Failure to comply with these instructions could result in property damage, severe personal injury, or death.
Figure 8 - Cascaded Boilers with Indirect Priority on a Single Boiler
Primary
Loop
Primary
Loop
Secondary
Circuit