Westlake (WLK) Arm NAPCO Launches Molecular-Based PVC Pipe Posted byZacks Equity Research December 13, 2021 Leave a comment on Westlake (WLK) Arm NAPCO Launches Molecular-Based PVC Pipe Westlake’s (WLK) subsidiary, NAPCO, launches a breakthrough molecular PVC pipe to lower carbon footprint and offer innovation.