Symbol 1605 from ISO 7000 - Title/Meaning: Exhaust gas Function/description: To identify exhaust gas, for example the gas expelled from an internal combustion engine at the end of each combustion cycle.
Additional information: 
Use to indicate air flow out of a tube or pipe. The symbol must be shown filled in all applications.
Own work using: iso.org/obp/graphics/grs/5fd4803b-a0f0-4e40-8ea4-b13e2daa508f 200.png
Vectorization:  Mrmw