P-K DURATION II
™ Indirect Domestic Water Heating System
12
3.4.4
Domestic Water Piping (Simplified)
The P-K Duration II system features constant recirculation on the domestic hot water piping. This circulation
pump offers 3-speed operation that can be selected by the operator. Constant circulation on the domestic hot
water side offers several advantages:
“Primes” the DHW loop ensuring the discharge water is at the correct temperature.
Maintains accurate temperature readings by maintaining flow across the temp gauges and RTD.
Minimizes heat exchanger scale formation by maintaining velocity across the plates.
Inhibits bacterial growth by preventing stagnant water conditions.
As domestic hot water is consumed throughout the building, hot water will exit the Duration II in the lower copper
piping (red arrow) and fresh makeup water will enter in the upper copper piping (blue arrow). The recirculation
pump circulates water through the heat exchanger to reduce the amount of hot spots that may form on the heat
exchanger, and keep the velocity to prevent scale build it. The recirculation path is indicated by the orange arrow
(Middle).
3.4.4.1
Domestic Water Piping Figure
