What is a T/D or Speedline flange?

These are old insert flange trade names that existed since the 1950’s, but are no longer in business. Many of these names, especially Speedline, still exists on company specification sheets. Our American Insert Flange series for single pipe applications satisfy these requirements. (Insert Flanges for Single Piping Applications) The T/D stood for tapered design, however, our Series S-150, S-300, SC-150, and SC-300 are proven substitutes for this style.