How to test if a PVC irrigation pipe is in use

You most likely got dirt or other debris in the line going to the faulty sprinkler head during the repair job. I would suggest removing the faulty head and then turn on that sprinker circuit to flush the line out. If there are other heads down stream from this head you should also remove those one by one and flush them as well. Finally take a good look at the "faulty" head and make sure that dirt did not get inside and cause it to malfunction. Most pop-up heads can be disassembled to permit inspection and removal of dirt and grit.

Schedule 40 PVC has a pressure rating of 120 psi to 810 psi, depending on pipe size, and temperature.

At 73°F the pressures are as follows:

• 2" = 280 psi
• 3" = 260 psi
• 4" = 220 psi
• 6" = 180 psi

Then as the temperature increases, you'll derate the values as such:

• 80°F - 88%
• 90°F - 75%
• 100°F - 62%
• 110°F - 51%
• 120°F - 40%
• 130°F - 31%
• 140°F - 22%

-Source

Schedule 80 PVC has a pressure rating of 210 psi to 1230 psi, depending on pipe size, and temperature.

At 73°F the pressures are as follows:

• 2" = 400 psi
• 3" = 370 psi
• 4" = 320 psi
• 6" = 280 psi

Then as the temperature increases, you'll derate the values as listed above.

-Source

Pressure depends on temperature, size, and schedule.