59SP6A: Installation, Start-up, Operating, Service and Maintenance Instructions
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
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Table 17 – Approved Combustion-Air and Vent Pipe, Fitting and Cement Materials
Venting System Length Calculations
The Total Equivalent Vent Length (TEVL) for
EACH
combustion air or vent pipe equals the length of the venting system, plus the equivalent length of
elbows used in the venting system from
.
Standard vent terminations or factory accessory concentric vent terminations count for zero deduction.
See vent system manufacturer’s data for equivalent lengths of flexible vent pipe or other termination systems.
DO NOT ASSUME
that one foot of
flexible vent pipe equals one foot of straight PVC/ABS DWV vent pipe.
Compare the Total Equivalent Vent Length to the Maximum Equivalent Vent Lengths in
Example 1
A direct-vent 60,000 BTUH furnace installed at 2100 ft. (640M). Venting system includes
FOR EACH PIPE:
70 feet (22 M) of
vent pipe, 65 feet (20 M) of combustion air inlet pipe, (3) 90º long-radius elbows, (2) 45º long-radius elbows, and a factory accessory
concentric vent kit.
Can this application use 2” (50 mm ND) PVC/ABS DWV vent piping?
MATERIALS
USA
1. All pipe*, fittings*, primers**, and solvents** must conform to American National Standards Institute (ANSI) standards and
American Society for Testing and Materials (ASTM) standards
2. See Table below for approved materials for use in the U.S.A.
3. UL 1738 vent systems must be composed of pipe*, fittings**, cements, and primers** from the same supplier.
CANADA
1. Installation in Canada must conform to the requirements of CAN/CSA B149 code.
2. Vent systems must be composed of pipe*, fittings*, cements, and primers from the same supplier and listed to ULC S636.
3. Not all materials below may be approved or listed to ULC S636.
4. Factory accessory concentric vent kits are ULC S636 listed.
Material
Description
Type
ASTM / ULC / UL Specification
Pipe*
Fittings*
Solvents/Primers**
Cements
PVC
Pressure Pipe
Schedule 40
D1785 / UL 1738
DWV
Schedule 40
D1785 / D2665
D2466
Cellular Core
Schedule 40
F891
or
F656
D2564
SDR 26
N/A
D2241
D2665
SDR 21
N/A
D2241
IPEX
Schedule 40
ULC S636
ULC S636
ULC S636
ULC S636
Royal Pipe
Schedule 40
ULC S636
ULC S636
ULC S636
ULC S636
ABS
ABS
Schedule 40
D1527
D2468
Clear Cleaner For
ABS†
D2235
DWV-IPS Sizes
Schedule 40
D2661
D2661
Cellular Core
DWV-IPS Sizes
Schedule 40
F628
CPVC
Pressure Pipe
Schedule 40
F441
F438
F656
F493
SDR
N/A
F442
N/A
IPEX
Schedule 40
ULC S636
ULC S636
ULC S636
ULC S636
Royal Pipe
Schedule 40
ULC S636
ULC S636
ULC S636
ULC S636
* PVC and ABS pipe may use either DWV or pressure rated fittings.
** Colored or tinted solvents or primers must be used where required by code in the USA
† ABS plastic does not require a primer before solvent cementing. A cleaner for ABS is recommended to remove any surface residue. ABS cleaners are
not subject to ASTM standards.
Polypropylene
Approved Manufacturer
Solvents Primers
Cements
Poly
Pro®
M & G Dura Vent
Not Permitted
Innoflue
®
Centrotherm
Not Permitted
NOTE: Polypropylene vent systems are UL
−
1738 and ULC S636 listed and assembled using mechanical fastening systems supplied by the vent
manufacturer.
Measure the required linear length of air inlet and vent pipe;
insert the longest of the two here
70 ft.
(22 M)
Use length of the longer of the vent
or air inlet piping system
Add equiv length of (3) 90º long-radius elbows
(use the highest number of elbows for either the vent or inlet
pipe)
3
x
3 ft.
(0.9 M)
=
9 ft.
(2.7 M)
Add equiv length of (2) 45º long-radius elbows
(use the highest number of elbows for either the vent or inlet
pipe)
2
x
1.5 ft.
(0.5 M)
=
3 ft.
(0.9 M)
Add equiv length of factory concentric vent term
0 ft.
Add correction for flexible vent pipe, if any
0 ft.
From Vent Manufacturer’s
instructions; zero for PVC/ABS DWV
Total Equivalent Vent Length (TEVL)
82 ft.
(25 M)
Add all of the above lines
Maximum Equivalent Vent Length (MEVL)
95 ft.
(29 M)
Is TEVL less than MEVL?
YES
Therefore, 2” pipe MAY be used
