Pool Fire - a flammable liquid surface burning with a stationary flame.

This seal is normally made by holding the torch flame stationary, blowing out a hole in the main glass body to match a second tube (hose connection in this example).

These processes include:oxygen-flame smelting process, the Vanyukov smelting process, smelting in a stationary unit with top blowing and smelting in a tilting furnace.