Refrigerant Vent-Line - Trane CVHE Installation Manual

CVHE-SVN02D-EN
Vent Piping

Refrigerant Vent-Line

General Recommendations
Both the purge and rupture disc vent
lines must be routed to outside
atmosphere. Use only material
compatible with the refrigerant in
use. The use of Poly Vinyl Chloride
(PVC) (not Chlorinated Poly Vinyl
Chloride (CPVC) piping is acceptable
if the pipe joint is properly primed
and if the adhesive used has been
tested for refrigerant compatibility.
Testing conducted in Trane
laboratories has approved the use of
the following materials for PVC pipe
construction.
Primer - Hercules, PVC Primer #60-
465, RectorSeal PVC Cleaner
-Smiling Sam CL3 Adhesive-
Hercules, Clear PVC, Medium Body,
Medium Set, #60-020 RectorSeal
PVC Cement-Green Gene 104.
Consult with the manufacturers of
any field-provided components or
materials added to the refrigerant-
side of the machine for acceptable
material compatibility.
During vent line construction,
provide a drip leg on the line that is
of sufficient length to accommodate
a minimum of one gallon of liquid.
Provide a standard capped
refrigerant service valve to facilitate
liquid removal. Accumulated liquid
must be drained from the drip leg
into an evacuated waste container
once every six months, at a
minimum, and more often if the
purge operates excessively.
Purge Discharge Vent Line
On CVHE, CVHF and CVHG units, the
purge discharge is factory-piped
downstream of the rupture disc on
the unit.
Rupture Disc Vent Installation
™
All CenTraVac chillers are equipped
with carbon rupture discs. A cross-
section of the rupture disc assembly
appears in Figure 10 along with an
illustration indicating the location of
the rupture disc on the suction
elbow.
If refrigerant pressure within the
evaporator exceeds 15 psig, the
rupture disc breaks, shell pressure is
relieved as refrigerant escapes from
the chiller.
When constructing the rupture disc
vent line, be sure to consult local
codes for applicable guidelines and
constraints.
Several general recommendations
for rupture disc vent line installation
are outlined below.
1. Verify that the vacuum support
side of the rupture disc is
positioned as shown in the cross-
section view that appears in
Figure 10.
Note: If the rupture disc was
removed for any reason, it must
be reinstalled as shown.
2. Do not apply threading torque to
the outside pipe assembly when
installing the connecting pipe.
CAUTION
Rupture Disk Damage!
Do not apply threading torque to the
outside pipe. Torque applied to the
outer pipe may result in damage to
the rupture disc assembly.
3. Support the vent piping, use a
flexible connection to avoid
placing stress on the rupture disc.
(Stress can alter rupture pressure
and cause the disc to break
prematurely.)
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