Alemite 51943 90 Degree Elbow Adapter, 1/4"-28 SAE-LT Taper Thread(m) x 1/8" Female NPTF

Hi, I am James and this is another episode of Heads Up for Hosers. In this video we will be discussing National Pipe Fittings. These fittings include NPT, NPTF, and NPSM. We will go into more detail later about what these stand for. First we are going to talk about the most basic Pipe threads, NPT commonly referred to as National Pipe Tapered. NPT threads were originally designed for water piping applications in low pressure situations. NPT creates a seal by a wedging action. It leaves a gap between the root and the crest as seen in this graphic This gap creates a possible leak path. Because of this wedge design, these fittings were never intended to be a connection that would be taken apart on a regular basis. Each time the connection is put back together the wedge must be driven deeper to create a seal. Soon there is no wedge left due to wear. To gain a proper seal in NPT fittings you