Vent And Air Intake Restrictions - Slant/Fin LYNX LX-85 Installation And Operating Instructions Manual

Lynx Model LX-85
PVC/CPVC PIPE GENERAL ASSEMBLY METHOD
The following are the recommended methods for cutting,
cleaning and connecting PVC and CPVC pipe, for both the
vent and air intake piping system:
1. When laying out the piping system, work from the boiler
vent and air intake adapter to the point of outside
termination.
2. Cut the PVC/CPVC pipe to the required lengths, and
pre-assemble the entire system, before sealing.
Disassembly after sealing, to make any corrections, will not
be possible.
3. Once the pre-assembled PVC/CPVC pipe vent and air
intake system is verified to be of the proper length pipe and
fitting orientation, begin disassembling and preparing the
pipes and fittings for the sealing process. This can be done
section by section, or the complete vent and air intake
system can be disassembled. It is recommended to mark
the various parts, before complete disassembly, to
eliminate the possibility of errors during re-assembly.
4. De-burr the inside and outside of every PVC/CPVC pipe, to
ensure that they engage fully into the fittings, and flow is
not compromised. A small chamfer on the outside of each
pipe can particularly aid in the final assembly process.
5. Wipe or knock out any debris from inside the PVC or
CPVC pipe, which may have accumulated there from the
cutting process or storage. Debris can cause operational
problems with the boiler combustion components.
6. Thoroughly clean the outside ends of each pipe, and the
inside of each fitting. The surfaces must be dry for the
sealing agents to work properly. Handle the prepared pipe
lengths away from the cleaned ends, and handle the
cleaned fittings, from the outside, to avoid contamination.
7. Re-assembly of the PVC or CPVC pipe should be done in
sections, to avoid the primer and cement drying before the
parts are engaged.
8. For each joint, first apply a coat of primer to the outside
sealing surface of the pipe and the inside sealing surface of
each fitting. Use only the primer type that is specified for
either the PVC or CPVC pipe that is bing utilized.
9. Before the primer dries, apply a coat of cement over it. A
second coat of cement can be applied, if necessary, but
must be done quickly and in a manner that avoids
unnecessary build-up that would cause obstruction inside
the system. Use only the cement type that is specified for
either the PVC or CPVC pipe that is being utilized.
10. Before the cement dries, insert the pipe into the fitting. A
slight twisting motion while pushing the pipe into the fitting
will aid in distributing the cement evenly and ensuring the
parts fully engage.
11. Quickly wipe the excess cement from the outside areas of
the joint. Discard any rags used to avoid later getting the
cement on hands, clothes and equipment.

VENT AND AIR INTAKE RESTRICTIONS

1. Maximum allowed equivalent vent and air intake length for
all of the approved vent and air intake materials is 100
equivalent feet.
2. Equivalent of vent or air intake length is sum of the
straight pipe lengths and equivalent length of elbows as
shown in the table on this page.
Figure 6.
3. The vent termination is in addition to the allowed
equivalent lengths.
4. Minimum vent length is 2 feet of straight pipe, plus one
90˚ elbow that is required.
5. Vent length restriction is for both direct and non-direct
vent installations.
EXAMPLE: Boiler model LX-85 is to be installed. The
combustion air is provided by air intake piping directly to the
boiler (direct-vent installation). The vent piping will be PVC
and installation location will require the use of 4 elbows for
the vent to run the termination. The air intake piping will also
be PVC, and also will require the use of 4 elbows.
In this case, the maximum straight pipe vent length that can
be utilized with the 4 elbows would be: 100' - (4' x 5') = 80'.
Since the air intake pipe also is PVC and requires the use of
4 elbows, the maximum straight pipe air intake length that
can be utilized is also 80 feet.
If the air for combustion were taken from the boiler room
(non-direct vent installation), still the maximum straight vent
length would be 80 feet.
Equivalent Length of Various 90-Degree Elbows
Manufacturer
Heat-Fab, Inc. Saf-T Standard
elbow
Heat-Fab, Inc. Saf-T, tight radius elbow
ProTech System, Inc. FasNseal
Flex-L International, Inc. StaR-34
Z-Flex, Inc. Z-Vent
N/A PVC, Schedule 40
N/A CPVC, Schedule 40
Equivalent
Type/System
Length (Feet)
7
3
6
6
6
6
5
5