Plastic pall ring for filtering waste gas: 1.material:PE,PP,RPP,PVC,CPVC,PVDF 2.diameter:16mm,25mm,38mm,50mm, ... heat resistant and chemical corrosion resistant plastics, including polyethylene (PE), polypropylene (PP), reinforced polypropylene (RPP), polyvinyl chloride (PVC), chloridized polyvinyl chloride (CPVC) and ...