Pipe Designations

First two digits:
WP stands for Weldable & made from Pipe
WC stands for Weldable & made from Casting

Next digits: Example
A/B/C stands for items equivalent to grade B WPB, WPC S stands for Seamless Construction WP-S
W stands for Welded fittings WP-W
WX stands for all welds are 100% radiographed WP-WX WU stands for all welds are 100% ultrasonically tested WP-WU L stands for low temp service WPL6 (Here 6 denotes 60 ksi strength)