Related Legal Terms & Definitions. 1  COMPETENT WITNESS One who is legally qualified to be heard to testify in a cause. 2  RESPECTABLE WITNESS One who is competent to testify in a court of justice. 3  CREDIBLE WITNESS A credible witness is one who is competent to give evidence, and is worthy ofâ¦.
In general, combustibility of polymers depends on their chemical structures. Polymers with more carbon atoms in their macromolecular structure (e.g., PE, PP, PS, PMMA) are more combustible than polymers containing halogen atoms (e.g., PVC, PVDC, PTFE).
PVC (POLYVINYL CHLORIDE) is, by far, the most common. plastic material used for plastic pipe. Its basic properties are. chemical inertness, corrosion and weather resistance, high. strength to weight ratio, electrical and thermal insulators. The service temperature is 140Â°F. PVC has been used. successfully for 40 years in such areas as chemical. processing, industrial plating, chilled water distribution, deionized water, and chemical drainage. Care should be. taken to avoid using with Ketones, Chlorinated.