Piping Installation - Zehnder Rittling HP Series Installation, Operation And Maintenance Manual

Piping
installation
Rigid male pipe
NPTF with
dryseal applied
crimp on fitting
UL-94VO fire-rated
thermoplastic inner
tube bonded to
stainless steel
outer braid
37° female JIC
swivel crimp on fitting
Overall length
(without adaptor)
37° male JIC x male pipe thread
NPTF with dryseal applied
Figure 9: Typical horizontal unit installation
Note
When antifreeze is used in the loop, ensure
n n
that it is compatible with the Teflon
pipe joint compound that is applied.
12
Installation of supply and
return piping
Follow these piping guidelines:
Install a drain valve at the base
n n
of each supply and return riser
to facilitate system flushing.
Install shut-off/balancing
n n
valves and unions at each
unit to permit unit removal for
servicing.
Place strainers at the inlet of
n n
each system circulating pump.
Select the proper hose length
n n
to ensure slack between
connection points.
Do not exceed the minimum
n n
bend radius for the hose
selected (refer to Table 1).
Tighter bends may cause the
hose to collapse resulting in
reduced water flow.
Table 1: Metal hose
minimum bend radii
Hose
diameter
1/2" (12.7 mm)
3/4" (19.1 mm)
1" (25.4 mm)
Insulation is not required on loop
water piping except where the
piping runs through unheated
areas, outside the building or
when the loop water temperature
is below the minimum expected
dew point of the pipe ambient
conditions. (Insulation is required
for ground loop applications in
most climates.)
Pipe joint compound is not
necessary when Teflon
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 external pipe threads of
the fitting adapters (never on
tape or
®
the threads of the flare side of
a fitting). Prevent sealant from
reaching the flared surfaces of
the joint.
Maximum allowable torque for
brass fittings is 30 ft-lbs (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 are available for
use with Zehnder Rittling units.
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 9.)
Install hose assemblies properly
and check regularly to avoid
system failure and reduced
Minimum bend
service life.
radius
2-1/2" (6.4 cm)
4" (10.2 cm)
5-1/2" (14 cm)
Corrosive system water requires
corrosion resistant fittings and
hoses, and may require water
treatment.
Do not bend or kink supply lines
or hoses.
Piping must comply with all
applicable codes.
thread
®
Do not allow hoses to rest
against structural building
components. Compressor
vibration may be transmitted
through the hoses to the
structure, causing unnecessary
noise complaints.