While removing paint is not a complicated process, most standard techniques for paint removal involve flat surfaces. Removing paint from a curved surface presents a greater challenge, especially if the surface is fully rounded, like a metal pipe. Stripping paint from a metal pipe uses much the same process as that of a painted wall, but with a few variations in materials and techniques.
Lay newspaper on the floor beneath the pipes; some of the paint stripper will inevitably drip and you don't want that on the floor, as it will damage any paint or finish there.
Coat a section of the pipe in gel paint stripper using a disposable brush. Cover about as much of the pipe as you think you can scrape in one go before your arm gets tired. Paint the stripper on thinly, but cover the entire pipe (or every part that's painted).
Let the paint stripper sit for a few minutes, soaking in and dissolving the paint. Consult the manufacturer's instructions for recommendations on how long to wait.
Scrape as much of the gel and paint away as you can using the metal scraper. Though the scraper is flat and the metal pipe round, you'll be able to remove most of the paint by lining up the edge of the scraper parallel to the pipe rather than perpendicular, then moving the scraper around the circle of the pipe.
Apply a second, lighter coat of stripper to the same area. Wait for it to set, and scrape again.
Repeat with additional sections of pipe until you've cleared most of the paint from all of the pipe, leaving only smaller streaks and smears of residual paint.
Rub down the pipes with a damp, coarse sponge to remove traces of melted paint and stripper.
Remove the remaining paint with steel wool. Wearing work gloves, press your fingertip against the wool to rub through it and focus the pressure and scrubbing on the areas that need it most.