Common Well Screen Designs, Including Advantages and Limitations
This is casing with vertical slots perforated by a cutting torch. Fortunately, this practice has fallen into disfavor, and is infrequently used today. The only reason for inclusion of such material in a water well is lack of an alternative. The disadvantages of torch cut slots include a low area of opening, high corrosion at the ragged torch cut edges, slag, irregular uncontrolled openings, weakness (particularly in collapsing strength) and a great tendency to clog. Even low cost is not an advantage of this material, since torch cutting with oxygen-acetylene gas is a slow process.