I am working on fitting new air compressors to an existing system. On the drawing for the new compressors i have flanges DIN 2635 ND 40 C 32 - C 38, C28.8 and DIN 2633 C 32. ND is the pressure rating, C 32 - C 38 refers to the max OD of the pipe and C 28.8 the material. Is there a web site that...