What Does Egg Shape Plug (ESP, ESTP) Mean?
Egg shaped plugs (ESP) are used to plug ovoid or oval shaped pipes. ESTP are fitted with a high pressure bypass. They are typically made of a composite of rubber, nylon, and/or Kevlar. For test applications, egg shaped plugs are utilized when detecting spot leaks.
Also noted as egg shaped test plugs (ESTP),
Trenchlesspedia Explains Egg Shape Plug (ESP, ESTP)
Aside from their shape, the technical features of egg shaped plugs are the same as conventional plugs. Egg shaped plugs are normally inflatable in order to attach tightly to the diameter of a given pipe, although rigid aluminum plugs can also be used. Plugs are employed to halt or restrict product flow in order to keep a pipe dry while rehabilitation or construction takes place. Various plugs are rated for different pressures and temperatures depending on their intended specific application.