How big valves are used in the DN90 pipeline?
If you use a 97 tube, the inner diameter of 89- phi 90., nominal pressure is low, then try to use DN80, DN80 valve diameter of 80, you can try butt welding
DN is the nominal diameter, only DN80, DN100.It is estimated that your pipe is outside diameter 89mm, that is DN80, that is to choose DN80 valve.
If you use a 97 tube, the inner diameter of 89- phi 90., nominal pressure is low, then try to use DN80, DN80 valve diameter of 80, you can try butt welding
