Vent Line Installation - Trane CVHE Installation, Operation And Maintenance Manual

to a 15 psig (103.4 kPaG) rupture disk relief device.
The pipe length provided by the table is in
"equivalent feet. " The vent-line length in equivalent
feet is the sum of the linear pipe length plus the
equivalent length of the fittings (e.g., elbows).

Vent Line Installation

Important: Before constructing the rupture disk vent
line, consult local codes for applicable
guidelines and constraints.
All CenTraVac centrifugal chillers are equipped with
rupture disks. If refrigerant pressure within the evaporator
exceeds 15 psig (103.4 kPaG) the rupture disk breaks and
shell pressure is relieved as refrigerant escapes from the
chiller.
A cross-section of the rupture disk assembly appears in
Figure 19, p. 32 along with an illustration indicating the
location of the rupture disk on the suction elbow.
Important: If a RuptureGuard is to be installed, remove
and discard the factory-installed rupture
disk; for more information, refer to
Installation, Operation, and Maintenance:
RuptureGuard Pressure Relief System
Option (CTV-SVX06*-EN, or the most recent
version).
Several general recommendations for rupture disk vent
line installation are outlined below.
Note: If the rupture disk was removed for service or vent
line piping installation, the rupture disk must be
reinstalled (as shown in
the following procedure and contact CenTraVac
Technical Service when reinstalling the rupture
disk.
• Verify that the vacuum support side of the rupture disk
is positioned as shown in the cross-section view that
appears in Figure 19, p.
– Install the two bottom bolts though the pipe
flanges.
– Install the rupture disk with a gasket on each side
between the pipe flanges. Orient the disk with the
reference arrow or vacuum support bar facing the
chiller side as shown in
– Install the two top bolts.
– Center the disk and gaskets to the flange bore.
– Hand tighten all bolts assuring equal pressure.
– Use a torque wrench set to 240 in·lb (27.1 N·m) with
a 9/16-in. socket.
– Tighten bolts in a star pattern, one half turn each, to
maintain even pressure on the disk.
– Final torque on all bolts should be 240 in·lb
(27.1 N·m).
• When attaching the vent line to the chiller, do not apply
threading torque to the outside pipe of the rupture disk
assembly.
CVHE-SVX02H-EN
Figure 19, p. 32). Refer to
32.
Figure 19, p. 32.
NOTICE:
Rupture Disk Damage!
Failure to follow instruction could result in damage to
the rupture disk assembly. Do not apply threading
torque to the outside pipe.
• Provide support as needed for the vent line. Do not use
the rupture disk assembly to support the vent line
piping.
• Use a flexible connection between the vent-line and
the rupture disk assembly to avoid placing stress on
the rupture disk. (Stress can alter rupture pressure and
cause the disk to break prematurely.) The flexible
connector used to isolate the rupture disk from
excessive vent line vibration must be compatible with
the refrigerant in use. Use a flexible, steel connector
such as the stainless-steel type MFP , style HNE, flexible
pump connector (from Vibration Mounting and
Control, Inc.) or equivalent. Refer to
a recommended relief piping arrangement.
• An individual vent line is normally installed for each
relief device. It is permissible to manifold the rupture
disks of several machines into a common vent line
provided that the appropriate ASHRAE Standards and
local code requirements for manifolded relief devices
are followed.
Note: Figure 20, p. 32
vent lines.
WARNING
Pressure-Relief Device Discharge Hazard!
An improper vent-line termination could result in death
or serious injury or equipment damage. When a
pressure-relief device operates, it could discharge a
large amount of fluid and/or vapor. Units MUST be
equipped with a vent-line termination that discharges
outdoors in an area that will not spray refrigerant on
anyone.
NOTICE:
Proper Refrigerant Vent Line Termination!
Failure to properly terminate a refrigerant vent line
could result in equipment damage. Improperly
terminating a refrigerant vent line could allow rain to
enter the line. Accumulated rainwater could cause the
relief device to malfunction; or, in the case of a rupture
disk, the rainwater pressure could cause the disk to
rupture, allowing water to enter the chiller.
• Route the vent-line piping so that it discharges
outdoors in an area that will not spray refrigerant on
anyone. Position the vent line discharge at least 15 feet
(4.572 meters) above grade level and at least 20 feet
(6.096 meters) from any building opening. Provide a
vent line termination that cannot be blocked by debris
or accumulate rainwater.
Vent Piping
Figure 20, p. 32
does NOT apply for manifolded
for
31