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).
Description: PVC is now the de-facto standard in home waste line materials. It is a strong, chemical-resistant rigid pipe that is heat resistant and easily cut and fit. It is often used to repair sections of broken cast-iron waste pipe, as well as repairs to other drain lines. Prevalent Use: Use for sanitary waste lines, vent pipes, and drain traps.