No you don't necessarily have to have it straight depending on the material if its bendy and u are able to get air through it
Vent pipe inspection kit
Vent pipe cleaning should be performed annually to ensure optimal performance and safety.
To properly vent a bathroom fan through the wall, you should first determine the best location on the wall for the vent. Then, cut a hole in the wall for the vent pipe. Connect the vent pipe to the fan and secure it in place. Finally, seal any gaps around the vent pipe to prevent air leaks.
Definition: Wet vent means a waste pipe that also serves as a vent pipe
blockage in vent tiring to relieve waste pipe
To install a dryer vent properly, first choose the right location on the wall for the vent. Then, cut a hole in the wall and attach the vent hood. Connect the vent pipe to the hood and secure it with clamps. Make sure the vent pipe is as straight and short as possible to maximize efficiency. Finally, seal any gaps with caulk or foil tape to prevent air leaks.
B-vent pipe.
A pipe that vents fumes
To properly install a dryer vent, first choose a suitable location for the vent on an exterior wall. Then, cut a hole in the wall and attach the vent hood. Connect the vent pipe to the hood and secure it with clamps. Make sure the vent pipe is as straight and short as possible to maximize efficiency. Finally, seal any gaps with caulk or foil tape to prevent air leaks.
Some municipal building codes allow it, but most do not. You should use smooth rigid metal vent pipe (typically aluminum) instead.
Yes a vent pipe can be painted AFTER it has passed inspections and some localities want the piping labeled "Vent"
No. You vent air from a sewer line.