Threaded connections for Pipe

Of standard types of pipe by pipe has some type of connection which are threaded .
Types of threaded pipe typically used for low pressure and fluid service has MSDS harmless like is (water , air and condensate ).
No portion of high pressure piping service using the threaded pipe ends to be used . threaded pipe simplify installation and maintenance . I need to know is the pipe that is used to service this type of use that is made seamles pipe using Senai or lathe .
Threaded pipe is only used in certain sizes . not all pipe sizes using dikarena screw mounting difficulties when instance sizes above NPS 2 "
For the threaded pipe fitting as for the materials and tools used :
1 . Key pipeline 2pcs
2 . Seal Tape PVC
3 . Union
4 . socket traded
Mechanical Installation of threaded pipe
notice first the type of screw that will be installed in accordance with the partner socket . then give the tape seal on any threaded pvc pipe at the end of the pipe and then use a key to hold the socket and rotate the pipe as shown.