what are the major difference between pipe and tube

People use the phrases  pipe and tube  interchangeably, and that they assume that each are the same. However, there are great variations among pipe and tube.   The brief solution is: A PIPE is a  spherical tubular  to distribute fluids and gases, unique through a nominal pipe size  (NPS or DN)  that represents a difficult indication of the pipe conveyance capability; a  TUBE  is a spherical, square, squared or oval hole phase measured through  outdoor diameter (OD)  and wall thickness (WT), expressed in  inches or millimeters.   What is Pipe? Pipe  is a hole phase with  spherical pass phase  for the conveyance of merchandise. The merchandise consists of fluids, gas, pellets, powders and more.   The  maximum critical dimensions  for a pipe is the outer diameter (OD) collectively with the wall thickness (WT).  OD minus 2 instances WT  (SCHEDULE) decide the interior diameter (ID) of a pipe, which determines the liquid capability of the pipe.   As defined above, the interior diameter is