Installer’s Guide
PVC VENT FITTING MATERIAL
These fittings are available from your Gas Furnace Distributors.
Straight Pipe Sections, Couplings, 45° Elbows, 60° El- bows, 90° Elbows, Vent or Sanitary Tee, or other neces- sary fittings may be 2", 2½", 3", or 4" diameter. The al- lowable materials are shown in Table 8.
VENT FITTING MATERIAL – PLASTIC
Gas and liquid tight single wall vent fittings, designed for resistance to corrosive flue condensate, MUST be used throughout.
Listed in Table 10 & 11 are 2", 2½", 3", and 4" size fittings that meet these requirements. The materials listed are various grades of PVC and ABS plastic.
PIPE JOINTS: All joints must be fastened and sealed to prevent escape of combustion products into the build- ing.
NOTE:
It is recommended that the first joints from the furnace be connected and sealed with high temperature RTV. This will enable the pipes to be removed later without cutting.
Be sure to properly support these joints.
BONDING OF PVC
Commercially available solvent cement must be used to join the pipe and fittings. Follow instructions on the container carefully.
Procedure for Cementing Joints:
1.Cut pipe square, remove ragged edges and burrs. Chamfer end of pipe, then clean fitting socket and pipe joint area of all dirt, grease, moisture or chips.
2.After checking pipe and socket for proper fit, wipe socket and pipe with
DO NOT ALLOW PRIMER TO DRY BEFORE AP- PLYING CEMENT.
3.Apply a thin coat of cement evenly in the socket. Quickly apply a heavy coat of cement to the pipe end and insert pipe into fitting with a slight twisting movement until it bottoms out.
4.Hold the pipe in the fitting for 30 seconds to pre- vent tapered socket from pushing the pipe out of the fitting.
5.Wipe all excess cement from the joint with a rag. Allow 15 minutes before handling. Cure time varies according to fit, temperature and humidity.
NOTE:
Follow venting instructions carefully when using PVC cement.
IMPORTANT:
All joints must be water tight. Flue condensate is some- what acidic, and leaks can cause equipment damage.
Connection of the pipe and collar of the combustion air inlet should just be a friction fit. It is recommended that the inlet air joint be sealed with RTV type sealant to allow the joint to be separated for possible future ser- vice. The inlet and vent pipes must be properly sup- ported throughout the entire length.
TABLE 9
PLASTIC PIPE DESIGNATIONS
PVC
ASTM STANDARD | PIPE TYPE | ALLOWABLE TEMPERATURE | MARKING |
|
|
|
|
F891 | CELLULAR CORE | *158 | ASTM F891 |
|
|
|
|
D2665 | DWV PIPE | **158 | ASTM D2665 |
|
|
|
|
D1785 | SCH 40, 80, 120 | **158 | ASTM D1785 |
|
|
|
|
D2241 | SDR SERIES | **158 | ASTM D2241 |
|
|
|
|
| CPVC |
|
|
ASTM STANDARD | PIPE TYPE | ALLOWABLE TEMPERATURE | MARKING |
|
|
|
|
D2846 | CPVC 41 | **212 | ASTM D2846 |
|
|
|
|
F441 | SCH 40, 80 | **212 | ASTM F441 |
|
|
|
|
F442 | SDR SERIES | **212 | ASTM F442 |
|
|
|
|
| ABS |
|
|
ASTM STANDARD | PIPE TYPE | ALLOWABLE TEMPERATURE | MARKING |
|
|
|
|
D2661 | SCH 40 DWV | ***180 | ASTM D2661 |
|
|
|
|
F628 | SCH 40 DWV CELLULAR CORE | ***180 | ASTM F628 |
|
|
|
|
*- Allowable temperatures based on classifications covered in ASTM D4396 [Deflection Temps Under Load (264 PSI)]
**- Allowable temperatures based on classifications covered in ASTM D1784 [Deflection Temps Under Load (264 PSI)]
***- Allowable temperatures based on classifications covered in ASTM D3965 [Deflection Temps Under Load (264 PSI)]
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