Learning about the pressure and temperature ratings of common landscape and irrigation supplies is a very important step when using PVC fittings for home projects. Many of you will be using the information on our resource center to learn how to do common jobs around your homes that most people rely on landscapers for. As such, it's worth taking the time to learn a bit about the landscape supplies you will be working with – namely PVC Pipe and fittings. Below are 2 charts; the first will display the pressure ratings of PVC Fitting Schedule 40 and PVC Fittings Schedule 80. The second chart will track the pressure derating of the fittings that results when the operational temperature of the pipe or fittings changes.

The column "Nominal Pipe Size (In)” denotes the fitting or pipe size. The column "Max. Working Pressure PSI” refers to the maximum working pressure PSI that the corresponding fitting can withstand. Basically, the larger the diameter of your PVC fitting or PVC Pipe length, the less pressure it can withstand. These Maximum Working Pressure figures rely on the fact that your PVC products will be used in a location providing optimal temperature year round. For PVC fitting Schedule 40 and PVC fittings Schedule 80, the optimal temperature (at which PVC can operate at the highest PSI) would be 73 degrees Fahrenheit. As the temperature of the PVC increases the pressure that the PVC can withstand will decrease. The chart below will illustrate the pressure derating of PVC as temperatures increase.