PVC fittings are used in many commercial and residential applications. PVC is very durable and can be used above or below ground. These fittings provide many benefits such as self-extinguishing, rigidness, great tensile strength and impact resistance. The most common uses are found in water, sewage, industrial processes, gas and irrigation. Schedule 40 & 80 represents the wall thickness of the PVC fittings. Schedule 40 fittings are ideal for light duty applications. For high-pressure and more corrosive environments, schedule 80 is a better choice.