From the Super Mario Wiki
Fire Pressures are a type of device appearing in Super Mario Galaxy and its sequel, Super Mario Galaxy 2. They are similar to Water Shooters, but as their name suggests, they shoot fire instead of water. They resemble the nozzle part of F.L.U.D.D. from Super Mario Sunshine, except in red. They are functionally similar to flamethrowers, which appear in Super Mario 64.
Super Mario Galaxy
In Super Mario Galaxy, their nozzles shoot long-ranged flames at Mario or Luigi. They are first found in Bowser's Star Reactor and re-appear in the Deep Dark Galaxy, Bubble Blast Galaxy, one fireball-shooting one on Mecha-Bowser in the Toy Time Galaxy, and two others on the Undergrunt Gunner Planet from the same galaxy aforementioned.
Super Mario Galaxy 2
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