[MW:18929] 64'' Sch 40 Pipe Thickness & XS Pipe Thickness

Dear Members

I have the following doubts to clear in the fabrication of large bore CS  pipe

As per our contract all the large bore pipes are Sch 40 but they provide the material and as per the design all the pipes are Sch  XS

1, What is thickness difference between Sch 40 & XS and how  I can prove this one according to the international standard

2. I have any wright to claim for extra cost because of the thickness difference

Please give your valuable advice

Thank You 

BEST REGARDS

JAMES ABRAHAM|Email - jamesmundokulthu@yahoo.com