Valves are not subject to copyright. These valves are patented, as noted in the article.
Probably an equally good valve design whose patent has expired could be used instead. It is not uncommon to patent a new design just different enough, but not actually better, to avoid competition.
Probably an equally good valve design whose patent has expired could be used instead. It is not uncommon to patent a new design just different enough, but not actually better, to avoid competition.