weldable made from pipe (WP), with equivalent grade B;
weldable made from casting (WC), with equivalent grade B;
weldable made from pipe, low temperature service, with 60ksi strength (WPL6)
This Grade is associated with ASTM A420 for pipe fittings manufactured of Wrought Carbon Steel. WPL6 is a normalized grade of carbon steel that has been Charpy Impact tested at -50 degree F for use in low temperature service. See Also ASTM A333 Grades 1 and 6 (for pipe) and A350 LF2 for flanges.
WPL6 and SA350 LF2 are different materials with distinct properties and specifications. WPL6 is generally used for low-temperature applications and may not meet all the requirements of SA350 LF2, which is specifically designed for low-temperature service and has defined mechanical properties. Therefore, while they may be used in similar applications, substituting one for the other without proper analysis and testing is not recommended. Always consult relevant standards and specifications before making material substitutions.