Loading... Please wait...

Categories

Temperature and Pressure Ratings of PVC

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.

Nominal Pipe
Size (Inches)
Sch 40 Max. Pipe
Working Pressure PSI
Sch 80 Max. Pipe
Working Pressure PSI
1/8" 810  
1/4" 780  
3/8" 620  
1/2" 600 509
3/4" 480 413
1" 450 378
1-1/4" 370 312
1-1/2" 330 282
2" 280 243
2-1/2" 300 255
3" 260 225
3-1/2" 240  
4" 220 194
5" 190 173
6" 180 167
8" 160 148
10" 140 140
12" 130 137
14" 130  
16" 130  


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.

Operating
Temp (°F)
De-Rating
Factor
73 1.00
80 0.88
90 0.75
100 0.62
110 0.51
120 0.40
130 0.31
140 0.22

Example: What's the Maximum Working Pressure of a 6” Schedule 40 pipe length at 110 degrees Fahrenheit? Answer: 180 PSI X .51= 91 PSI max at 110 degrees.