XH
XH is an abbreviation of EXtra Heavy
and stands for the wall thickness of pipes, fittings, and some flanges.
XS
XS is an abbreviation of EXtra Strong
and stands for the wall thickness of pipes, fittings, and some flanges.
XXH
XXH is an abbreviation of Double Extra Heavy
and stands for the wall thickness of pipes, fittings, and some flanges.
XXS
XXS is an abbreviation of Double EXtra Strong
and stands for the wall thickness of pipes, fittings, and some flanges.
