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11
Installation, Operation & Maintenance - HKV Series
Installation of Supply and Return Piping
Follow these piping guidelines.
1. Install a drain valve at the base of each supply and
return riser to facilitate system flushing.
2. Install shut-off / balancing valves and unions at each
unit to permit unit removal for servicing.
3. Place strainers at the inlet of each system
circulating pump.
4. Select the proper hose length to allow slack between
connection points. Hoses may vary in length by +2%
to -4% under pressure.
5. Refer to Table 1. Do not exceed the minimum bend
radius for the hose selected. Exceeding the minimum
bend radius may cause the hose to collapse which
reduces water flow rate. Install an angle adapter to
avoid sharp bends in the hose when the radius falls
below the required minimum.
Insulation is not required on loop water piping except
where the piping runs through unheated areas or
outside the building or when the loop water temperature
is below the minimum expected dew point of the
pipe ambient.
Insulation is required if loop water
temperature drops below the dew point.
Pipe joint compound is not necessary when Teflon
threaded tape is pre-applied to hose assemblies or when
flared-end connections are used. If pipe joint compound
is preferred, use compound only in small amounts on the
male pipe threads of the fitting adapters. Prevent sealant
from reaching the flared surfaces of the joint.
Table 1: Metal Hose Minimum Bend Radii
Figure 3: Supply/Return Hose Kit
Piping Installation
Note: When antifreeze is used in the loop, assure
that it is compatible with Teflon tape or pipe joint
compound employed.
Maximum allowable torque for brass fittings is 30 foot-
pounds [41 N-m]. If a torque wrench is not available,
tighten finger-tight plus one quarter turn. Tighten steel
fittings as necessary.
Optional pressure-rated hose assemblies designed
specifically for use with Comfort-Aire/Century units are
available. Similar hoses can be obtained from alternate
suppliers. Supply and return hoses are fitted with swivel-
joint fittings at one end to prevent kinking during
installation.
Refer to Figure 3 for an illustration of a Supply/Return
Hose Kit. External Pipe Thread (MPT) adapters secure
hose assemblies to the unit and risers. Install hose
assemblies properly and check them regularly to avoid
system failure and reduced service life.
Rib Crimped
Length
(2 ft [0.6m] Length Standard)
Swivel
Brass
Fitting
Brass
Fitting
MPT
Reborde Acanalado
Longitud
(Long. Estándar de 2 pies)
Accesorio
Giratorio
de Bronce
Accesorio
de Bronce
MPT
MPT
MPT
Rib Crimped
Length
(0.6m Length Standard)
Swivel
Brass
Fitting
Brass
Fitting
MPT
MPT
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CAUTION!
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CAUTION!
Piping must comply with all applicable codes.
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CAUTION!
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Hoses in Inches
Minimum Bend Radius
1” [25.4mm]
5.5” [140mm]
1.25” [31.8mm]
7.0” [178mm]
1.5” [38.1mm]
8.5” [216mm]
CAUTION!
Corrosive system water requires corrosion
resistant fittings and hoses and possibly water treatment.
WARNING!
Do not bend or kink supply lines or hoses.
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WARNING!
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WARNING!
Polyolester Oil, commonly known as POE oil, is
a synthetic oil used in many refrigeration systems including
those with HFC-410A refrigerant. POE oil, if it ever comes
in contact with PVC or CPVC piping, may cause failure of
the PVC/CPVC. PVC/CPVC piping should never be used
as supply or return water piping with water source heat
pump products containing HFC-410A as system failures and
property damage may result.
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WARNING!
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