Some vent pipes are galvanized iron.
Pipe against roof distance between.
Such boot assembly is just not going to work well two inches from a chimney.
Spacing between pipes on a pipe rack larger spacing may be required if pipes have clamped supports.
A typical roof vent pipe is equipped with a sealing boot affixed to a flashing plate that is normally about 12 wide and about 16 dimension in the roof slope direction.
Always maintain the distance between supports as per project specification recommended support span table.
A length double the pipe diameter is considered appropriate for the part pointing downward.
Though some old homes may have pipes made of lead most drain piping is abs plastic cast iron or copper.
And for gas service 17 ft for 2 to 40 ft for 8.
Sinks lavatories bathtubs and laundry tubs may be served by 1 1 4 to 2 inch pipes.
For fiber reinforced plastic pipe frp support spacing in liquid service would vary from around 11 ft for 2 pipe to 22 ft for 8 pipe.
All open vent pipes that extend through a roof shall be terminated at least number typically 6 inches mm above the roof except that where a roof is to be used for any purpose other than weather protection the vent extensions shall be run at least 7 feet 2134 mm above the roof.
The roof or a wall the minimum distance must be 100 cm.
To determine spacing between 150 nb pipe 150 flange rating and a 100 nb pipe with 600 flange rating.
For 100 nb pipe and 150 nb 150 flange rating spacing 230 mm.
Between the outlet and any restriction e g.
For 150 nb pipe and 100 nb 600 flange rating spacing 255 mm.
To operate properly and safely each drain must be served by a vent line that carries sewer gases out through the roof.
Tim l thank you for your question.
Typical formula for spacing is as follows.
Consider the maximum distances from 2 cases.
Two feet or 24 is a code interpretation for distance between plumbing vent stack rooftop termination and the top of a chimney that is less than 3 ft.
Chimney and vent are near the ridge peak of the roof.
It is applicable to straight run pipe length only when a change of direction in a horizontal plane occurs it is suggested that the spacing be limited to times the standard pipe span.
The spacing between the 2 lines 255 mm.
For high density polyethylene hdpe the spacing would vary from 7 ft for 4 pipe with sdr diameter over thickness of 11 0 to 16 ft for 24 pipe.