The nominal pressure of the same specification C-class pipe is lower than the recommended application pressure of K-class tube.
Using casting molten iron with more than 18th, after adding the ball agent, through centrifugal ductile iron machine high-speed centrifugal casting pipe, called "Ductile iron Pipe."
C-grade tube is the latest international standard of ductile Iron pipe product name, the implementation of the standard code-named ISO2531:2009, the standard code, and the original standard iso2531:2003 of the K-class code compared. Pipe use unchanged. But the new standard (C-class tube) classification is to the pipe allows the classification of working pressure, and the original standard (K-grade tube) is the thickness of the pipe wall classification.