Circulator Sizing; Near Boiler Piping Connections - Lochinvar Knight XL 400 - 801 Installation & Operation Manual

6
Hydronic piping
12. Boiler purge valve:
Field supplied. The boiler purge valve is used to
remove entrapped air from the heat exchanger during
start-up.
13. System temperature sensor:
Lochinvar supplies a system temperature sensor. The
sensor is to be installed in the heating loop downstream
from the boiler hot water piping and heating loop
junction. The sensor should be located far enough
downstream to sense system diluted water temperature.
14. Y-Strainer:
Field supplied. A Y-strainer or equivalent multipurpose
strainer is recommended at the inlet of the heat exchanger
to remove system particles from older hydronic systems
and protect newer systems.

Circulator sizing

The Knight XL heat exchanger does have a pressure drop,
which must be considered in your system design. Refer to the
graphs in FIG's 6-5 and 6-6 for pressure drop through the
Knight XL heat exchanger.

Near boiler piping connections

Figure 6-4A Near Boiler Piping w/Y-Strainer
DIRT SEPARATOR
SYSTEM SENSOR
SYSTEM PUMP
Y-STRAINER
(RECOMMENDED)
BOILER PUMP
(continued)
DOMESTIC HOT
WATER PUMP
INDIRECT
DOMESTIC
HOT WATER
TANK
TO FLOOR
DRAIN
Installation & Operation Manual
Figure 6-4B Near Boiler Piping w/Low Loss Header
SYSTEM PUMP
SYSTEM SENSOR
AIR SEPARATOR
DRAIN
(TYPICAL)
AIR VENT VALVE
LOW LOSS HEADER
(TYPICAL)
DRAIN
VALVE
Y-STRAINER
(RECOMMENDED)
BOILER PUMP
Variable speed pump option
Variable speed pump setup
Before operation, ensure the following:
- Pump is set for an input signal of 0 - 10VDC
by the dip switches on the pump control
- Pump is set for external signal control
(if applicable)
- Pump is set for linear output (if applicable)
- If pump does not come equipped with a
0 - 10 VDC input option, an optional module
will be required from the vendor
SMART SYSTEM / Multi-temperature
loop control option
The Knight XL boiler is capable of producing up to
three (3) set point temperatures to meet different
space heating demands. When using more than one
temperature demand it is necessary to protect the
lower temperature loop from overheating. To help
aid with this protection, Lochinvar offers the Multi-
Temperature Loop Control Board Kit (RLY30086).
EXPANSION TANK
FAST FILL VALVE
INDIRECT
DOMESTIC
HOT WATER
TANK
TO FLOOR
DRAIN
39