PB Heat Peerless Boilers GM Series, Installation, Operation & Maintenance Manual

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11
E. EXPANSION TANK
1. Consult the tank manufacturer’s instructions for
specific information relating to tank installation. Size
the expansion tank for the required system volume
and capacity. See Table 11.1 for boiler’s water
content.
2. Expansion tanks are available with built-in fill valves
and check valves for reducing supply water pressure
and maintaining minimum system pressure. Check
the design features of the tank and provide valves as
necessary.
Refer to Figure 3.2 for typical expansion tank piping.
F. INDIRECT-FIRED WATER HEATER
Boiler may be used as heat source for indirect-fired
water heater. Refer to Figure 3.8 for typical piping.
Follow the instructions provided by the water heater
manufacturer. Pipe the water heater as if a separate
space heating zone.
G. FREEZE PROTECTION
For new or existing systems that must be freeze-
protected:
1. Glycol for hydronic applications is specially
formulated with inhibitors which prevent the glycol
from attacking metallic system components. Make
certain that the system fluid is checked for the correct
glycol concentration and inhibitor level.
2. Antifreeze solutions expand more than water. For
example, a 50% by volume solution expands 4.8%
in volume for a temperature increase from 32°F
(0°C) to 180°F (82°C), while water expands 3% with
the same temperature rise. Allowance must be made
for this expansion in system design.
3. The glycol solution should be tested at least
once a year and as recommended by the glycol
manufacturer.
4. For more information, consult the PB Heat Water
Installation Survey and the antifreeze manufacturer.
Figure 3.8: Typical Piping with Indirect-Fired Water Heater
WATER PIPING & CONTROLS
Use only inhibited propylene glycol solutions of up
to 50% by volume with water. Ethylene glycol is toxic
and can attack gaskets and seals used in hydronic
systems.
⚠
WARNING