23
NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.
LENNOX HEARTH PRODUCTS • MERIT PLUS
®
DIRECT VENT GAS FIREPLACES (MPD33/35/40/45) • INSTALLATION INSTRUCTIONS
5 in. (127 mm)
Radius Minimum
Flexible Vent Section
E. Attach Flex Vent to Termination
Secure Flex
components can be purchased
separately and attached to bulk lengths of
Secure Flex
flexible tubing cut to size at the
job site. Secure the flexible vent to the
Secure
Flex
terminations in the same manner (see
Figure 42
)
as it was attached to the adaptor.
NOTE: Secure Flex vent must be attached
to Secure Flex terminations only. DO NOT
substitute Secure Vent terminations or
the Secure Vent adaptor for Secure Flex
components. The collars of Secure Flex
terminations and adaptors have a different
circumference than what is used with the
Secure Vent pipe. Additionally, Secure Flex
components have an extended length center
tube for use in attaching the flexible vent.
See the appropriate sections and figures
shown throughout the venting section for
their installation requirments.
Figure 43
VERTICAL OR HORIZONTAL VENTING USING
SECURE FlEx
®
KITS ANd COMPONENTS
Secure Flex
®
venting kits and components may
be used in any venting application where rigid
Secure Vent
®
(SV4.5) direct vent components
can be used. All restrictions, clearances and
allowances that pertain to the rigid piping apply
to the flexible venting.
Secure Flex
kits may not
be modified; also, under no circumstances
may separate sections of flex pipe be joined
together
.
Secure Flex
kits may be added to
the end of a vent run made up of rigid
Secure
Vent
(SV4.5) vent sections provided that
doing so does not violate any of the venting
length, height, routing, horizontal to vertical
ratio requirements or clearance considerations
detailed in this manual.
Secure Flex
kits come with an included adaptor
that can be fitted to the appliance collar or the
inclined channel end of the last
Secure Vent
(SV4.5) vent section in a rigid system in the
exact same fashion as any other
Secure Vent
section. Align the dimpled end of the adaptor
over the previously installed section or appliance
collar, adjusting the radial alignment until the
four locking dimples of the adaptor are aligned
with the inlets of the four incline channels of the
last vent section or collar. Push on the adaptor
until it fully engages, then twist the adaptor
clockwise running the dimples down and along
the incline channels until they seat at the end
of the channels.
Attach the flexible vent to the adaptor as
follows
(see Figure 42)
:
A. Install the Inner Flex Pipe
1.
Install the small gear clamp loosely around
the inner flexible vent pipe, push it back out
of the way.
2.
Apply a bead of
Mill-Pac Black (700°F) high
temperature sealant - Catalog No. 10K81)
to
the inner adaptor collar, approximately 1/2
inch
from the end.
3.
Pull and extend the inner flexible vent pipe.
4.
Slide the inner flex pipe over the adaptor
collar. Ensure the flexible vent pipe completely
engages the adaptor collar to a distance of 1
3/4
inches from the end, and that it is free from
damage or tears.
5
. Slide the gear clamp down and tighten it
fully to secure the flexible vent to the adaptor
inner collar approximately 3/4
inch from the
end of the flex.
6
. Install
three screws 120 degrees apart
through the flexible vent pipe and into the
adaptor collar just below the gear clamp to
provide additional security to the connection.
B. Install the Outer Flex Pipe
1.
Install the large gear clamp loosely around
the outer flexible vent pipe, push it back out
of the way.
2.
Apply a bead of
Mill-Pac Black (700°F) high
temperature sealant - Catalog No. 10K81)
to
the outer adaptor collar; to the grooves of the
collar which extend approximately 1 inch from
the end and to the flat surface, approximately
1 3/8
inches from the end.
3.
Pull and extend the outer flexible vent pipe.
4.
Slide the outer flex pipe over the adaptor
collar. Ensure the flexible vent pipe completely
engages the adaptor collar to a distance of
1 3/4
"
from the end, and that it is free from
damage or tears.
5
. Slide the gear clamp down and tighten it
fully to secure the flexible vent to the adaptor
outer collar approximately 3/4
inch from the
end of the flex.
6.
Install
three screws 120 degrees apart
through the flexible vent pipe and into the
adaptor collar just below the gear clamp to
provide additional security to the connection.
C. Route Flex Vent
Ensure that the flex vent is properly routed to
provide the required clearance. Do Not allow the
flexible vent to bend in a radius tighter than 5"
(127 mm). Refer to
Figure 43.
Place the internal
flex vent spacers evenly and avoid kinking the
inner pipe. Support horizontal sections of flex
vent with metal straps at 2 ft (0.61 m) intervals.
d. Install Firestop/Spacers at ceilings and walls
When Secure Flex penetrates a wall or ceiling,
a firestop/spacer is required: use the SF4.5 VF
firestop/spacer for ceilings and the SF4.5 HF
firestop/spacer for walls.
GEAR
CLAMPS
Adaptor
(SV4.5RF)
Apply ONLY MIL-PAC BLACK HIGH
TEMPERATURE SEALANT (Catalog No.
10K81) to the outside surface of both
collars of the adaptor (be especially
careful to fill the grooves of the outer
collar to be covered by the flexible
pipe) and slide flexible pipe over
inner and outer adaptor collars.
NOTE: OUTER PIPE IS PULLED AWAY TO
SHOW THE DETAIL OF THE INNER PIPE
FLEX VENT
1-3/4 in. (44 mm)
Flexible Pipe and
Adaptor Outer
Collar Overlap
1-3/4 in. (44 mm)
Flexible Pipe and
Adaptor Inner
Collar Overlap
SECURING SCREW
(3 PLACES EQUALLY SPACED
JUST BELOW GEAR CLAMP)
Attach Adaptor to Appliance
Collar, or Secure Vent Sections
SECURING SCREW
(3 PLACES EQUALLY SPACED
JUST BELOW GEAR CLAMP)
Figure 42
