Brochure

1.4 Pumped liquids
Grundfos ALPHA circulators are suitable for the following
liquids:
• clean, thin, non-aggressive and non-explosive liquids, not
containing solid particles, fibers or mineral oil.
• cooling liquids, not containing mineral oil.
• domestic hot water with maximum 15 grain/gal (US),
maximum 149 °F (65 °C); maximum peak 158 °F (70 °C).
• softened water.
• If the pump is installed in a heating system, the water
must meet the requirements of accepted standards on
water quality in heating systems.
For water with a higher degree of hardness, contact
Grundfos.
ALPHA circulators must not be used for the transfer of
flammable liquids such as diesel oil, gasoline or similar
liquids, and must not be used to circulate aggressive liquids
such as acid or seawater.
In domestic hot water systems, the temperature of the
pumped liquid must always be above 122 °F (50 °C) due to
the risk of legionella. The temperature of the hot water
source must not be high enough to cause burns or scalding.
The pump must be permanently connected to the main
water supply and must not be connected with a hose.
The kinematic viscosity of water is 1 mm
2
/s (1 cSt) at 68 °F
(20 °C). If the pump is used for a liquid with a higher
viscosity, the hydraulic performance of the pump will be
reduced.
Example: 50 % glycol at 68 °F (20 °C) means a viscosity of
approximately 10 mm
2
/s (10 cSt) and a reduction of the
pump performance by approximately 15 %.
When selecting a pump, pay attention to the viscosity of the
pumped liquid. Additives that can or will disturb the
functionality of the pump must not be used.
Glycol
The ALPHA 1/2 15-55 and ALPHA 26-99 circulators are
designed for pumping clean water or up to 50/50 mixtures
by weight of glycol and water.*
To prevent the glycol mixture from degrading, temperatures
exceeding the rated liquid temperature must be avoided,
and the operating time at high temperatures must be
minimized.
It is important to clean and flush the system before adding
the glycol mixture.
To prevent corrosion or precipitation, the glycol mixture must
be checked and maintained regularly. If further dilution of
the supplied glycol is required, refer to the glycol supplier's
instructions.
* ALPHA1/2 26-99, if cooling liquid is used, requires
mixtures of water with anti-freezing media such as glycol or
ethanol down to 14 °F (-10 °C) with a validated temperature
profile. The viscosity increases depending on the type of
glycol, the mixture, and the liquid temperature, but the
viscosity must not exceed 10 cSt (10 mm/s2).
ALPHA HWR-D is suited for domestic hot water only.
ALPHA
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Product data