Hitachi YUTAKI M RASM-3WF2E Installation And Operation Manual page 30

be still frozen).
!
CAUTION
• Do not add glycol that has been exposed to air as glycol absorbs water from the environment.
Final glycol concentration can be lower than expected, allowing system to freeze up.
• Corrosion, that can damage gravely the system, is possible when glycol is added. Uninhibited
glycol with oxygen can become acidic & attack metal surfaces, forming galvanic corrosion
cells. The responsible installer must be a qualified water specialist & should decide which anti-
freeze solution is necessary for each site's conditions. Corrosion inhibitors must be selected
to counteract acids formed by glycol oxidation. Inhibitors with limited lifetime or containing
silicates are forbidden. Galvanized pipes must be avoided since they can precipitate inhibitors.
When using inhibitors, always follow manufacturer's instructions and ensure that the product is
appropriate for materials used in water circuit.
• Adding glycol to water circuit reduces the maximum allowed water volume of the system and
also capacity. Additional info can be found on Technical Catalogue.
5.3.7 Insulation
Water circuit piping must be insulated to prevent condensation and to reduce heat loss.
For outdoor water piping, recommended insulation thickness depends on piping length.
Recommended thickness values for an insulation of ʎ=0.039W/mK are shown in table below.
Piping length in.(mm)
<0.78 (< 20)
0.78-0.11 (20 - 30)
0.11-1.57 (30 - 40)
1.57-1.96 (40 - 50)
PMEN0657 rev.0 - 02/2024
Minimum insulation thickness in.(mm)
0.74 (19)
1.25 (32)
1.57 (40)
1.96 (50)
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