PVC is the most commonly used plastic material for manufacturing plastic pipe. It has a relatively high tensile strength and module of elasticity. These features make it stronger and more rigid than most other thermoplastics. It is also resistant to most acids, bases, salts, aliphatic solutions, oxidants and halogens. The joining methods for PVC are by solvent cementing, threading (Schedule 80 ONLY) or flanging. PVC has been used successfully in industries such as chemical processing, industrial planting, chilled water distribution, salt water, chemical drainage, irrigation systems and other industrial applications with corrosive fluid transfer. The pressure rating systems given are for solvent-cemented systems. When adding valves, flanges or other components, the system must be de-rated to the rating of the lowest component: threaded fittings are rated at 50% of solvent-cement systems; flanged fittings are rated at 150 psi; union fittings are rated at 235 psi. Please see manufacturers' recommendations for other ratings. Do not test or use PVC piping for air or compressed gasses.