A connection wire for 21mm the other end is connected to 4 points inside the pipe joint ball valve
Four is 1/2=DN15, 21mm data is not accurate, if it is metric thread, provide tooth pitch and thread diameter.
Four is 1/2=DN15, 21mm data is not accurate, if it is metric thread, provide tooth pitch and thread diameter.
DN20 is not the ball valve, 4 points that the size of the head with 20*15 change
