Bryant 355CAV installation instructions Combustion-Air and Vent Pipe Diameter

Table 5 – Approved Combustion-Air and Vent Pipe, Fitting and Cement Materials

ASTM				SOLVENT
SPECIFICATION
	MATERIAL	PIPE	FITTINGS	CEMENT	DESCRIPTION
(MARKED ON
				AND PRIMERS
MATERIAL)
D1527	ABS	Pipe	—	—	Schedule40
D1785	PVC	Pipe	—	—	Schedule40
D2235	For ABS	—	—	Solvent	For ABS
				Cement
D2241	PVC	Pipe	—	—	SDR21 & SDR26
D2466	PVC	—	Fittings	—	Schedule40
D2468	ABS	—	Fittings	—	Schedule40
D2564	For PVC	—	—	Solvent	For PVC
				Cement
D2661	ABS	Pipe	Fittings	—	DWV at Schedule40 IPS sizes
D2665	PVC	Pipe	Fittings	—	DWV
F438	CPVC	—	Fittings	—	Schedule40
F441	CPVC	Pipe	—	—	Schedule40
F442	CPVC	Pipe	—	—	SDR
F493	For CPVC	—	—	Solvent	For CPVC
				Cement
F628	ABS	Pipe	—	—	Cellular Core DWV at Schedule40
					IPS sizes
F656	For PVC	—	—	Primer	For PVC
F891	PVC	Pipe	—	—	Cellular Core Schedule 40 & DWV

355CAV

Installation Guidelines for Combustion Air Pipe and Vent Pipe

It is recommended that all pipes be cut, prepared, and preassembled before permanently cementing any joint.

1.Attach combustion air pipe and vent pipe per instructions in sections “Combustion Air Pipe” and “Vent Pipe.”

2.Working from furnace to outside, cut pipe to required length(s).

3.Deburr inside and outside of pipe.

4.Chamfer outside edge of pipe for better distribution of primer and cement.

5.Clean and dry all surfaces to be joined.

6.Check dry fit of pipe and mark insertion depth on pipe.

7.After pipes have been cut and preassembled, apply gener- ous layer of cement primer to pipe fitting socket and end of pipe to insertion mark. Quickly apply approved cement to end of pipe and fitting socket (over primer). Apply ce- ment in a light, uniform coat on inside of socket to prevent buildup of excess cement. Apply second coat.

8.While cement is still wet, twist pipe into socket with 1/4 turn. Be sure pipe is fully inserted into fitting socket.

9.Wipe excess cement from joint. A continuous bead of ce- ment will be visible around perimeter of a properly made joint.

10.Handle pipe joints carefully until cement sets.

11.Horizontal portions of the venting system shall be suppor- ted to prevent sagging. Support combustion air piping and vent piping a minimum of every 5 ft. (1.5M)(3 ft. (.91M) for SDR-21 or -26 PVC) using perforated metal hanging strap.

12.Slope combustion air piping and vent piping downward towards furnace a minimum of 1/4-in. per linear ft. with no sags between hangers.

13.Horizontal portions of the venting system shall be installed so as to prevent the accumulation of condensate.

14.Use appropriate methods to seal openings where combus- tion air pipe and vent pipe pass through roof or sidewall.

Combustion-Air and Vent Pipe Diameter

Determine combustion-air and vent pipe diameter.

1.Using Table 7, individually determine the diameter of the combustion-air and vent pipe allowed. If different, pick the larger of these two diameters and use this diameter for both combustion-air and vent pipes.

2.When installing vent systems of short pipe length, use the smallest allowable pipe diameter. Do not use pipe size greater than required or incomplete combustion, flame dis- turbance, or flame sense lockout may occur.

NOTE: Do not count elbows or pipe sections in terminations or within furnace.

NOTE: A 2-in. diameter pipe must be used within furnace casing. Make all pipe diameter transitions outside furnace casing.

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