12
NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.
The length adjustment from Flange to Flange is from
7 1/4” to 28 3/8”
. For
proper installation, the adjustable length must have adequate overlap and
sufficient allowance for thermal expansion.
If the length of the inner wall or the outer casing is too long, it can be cut.
However, keep I mind that the minimum overlap for the sliding inner wall
into the inlet end section is
8”
and the minimum overlap for the outer
casing is
1”
with the down stream section outer wall (See
Figure 15
).
NOTE
:
Installation of an
LA
joint to fittings, such as elbow and tees, is not
recommended. However, if its joint must be joined to one of these
fittings,The unflanged end of the tube should always point downward
or towards downward slope.
Figure 15 - Detail of Overlap of the Adjustable Length
Gas Flow
Desired
Length ”X”
Outer Casing
Length = X + 6”
Min. Outer Wall
Overlap = 1”
Min. Inner Wall
Overlap = 8”
Sliding Inner
Wall
Metal Tie Wrap
tighten stronger
Outlet end section
Inlet end section
The expansion length must be added to the minimum length of the LA so it may
compensate for abnormal and normal operating conditions.
The amount of expansion is calculated as follows:
Expansion
= Length (feet)/100 x Temperature rise (°F)/100
Minimum Length
=
Expansion
+ 7 1/4
”
NOTE
: It is recommended that the temperature used in the above formula be
at least 300°F higher than the expected normal operating temperature.
NOTE
: Adjustable Length cannot be used to correct misalignment or to
compensate for lateral movement or vibration. It is recommended
that the duct on both side of the LA joint is supported or guided to
ensure that it will not bind during operation. See Variable and
Adjustable Support section for typical applications.
INSTALLATION STEPS FOR THE ADJUSTABLE LENGTH
1. Place the sliding inner liner section (with the graphite band assembly on it) into a standard
section of DCL, DIS PRO or DAS PRO.
NOTE
: If the inner flue is too long, it may be cut to length while respecting the
minimum overlap of
8”
into the inlet end section duct plus the
expansion.
2. Secure the double flanged part of gasket collar assembly to the inlet end
section with the inner V-band
(BSI)
. See
Figure 16
.
NOTE
: See
JOINT ASSEMBLY
section for assembly of the V-Band
Figure 16 - Installation of Adjustable Length Steps 1 & 2
3. Extend the sliding inner liner to its correct length (up to the outlet end section)
and secure it with the V-Band (See
JOINT ASSEMBLY
section).
4. Strongly tighten the metal tie wrap so that the graphite packing is firmly compressed
against the inner flue. See
Figure 17
.
Gas
Flow
Figure 17 - Installation of Adjustable Length Steps 3 & 4
NOTE
: On horizontal run, make sure that the joint of the graphite packing gasket
is on the top side of the section.