Diy or call a pro? the ultimate guide to rpz backflow preventer testing

Backflow preventers are critical devices that protect drinking water systems from contamination, and RPZ (Reduced Pressure Zone) backflow preventers are specifically designed for high-hazard applications. Testing these devices regularly is essential to ensure they are functioning properly and maintaining water safety. Here’s a comprehensive guide on how to test RPZ backflow preventers:

Understanding RPZ Backflow Preventers

RPZ backflow preventers are mechanical devices that maintain a reduced pressure zone between the potable water system and potential sources of contamination. They achieve this by using two independently acting check valves and a relief valve. If either check valve fails, the relief valve opens to discharge water, creating a pressure drop that prevents backflow.

Testing Requirements

Testing RPZ backflow preventers is required by law in many jurisdictions to ensure compliance with plumbing codes and water safety regulations. The frequency of testing varies depending on local regulations, but it is typically recommended to test RPZ backflow preventers annually or more frequently in high-risk areas.

Test Equipment

To test RPZ backflow preventers, you will need the following equipment:

• Test gauge (with a range of 0-100 psi)
• Pressure source (e.g., hand pump)
• Test hose
• Adjustable wrench

Test Procedure

1. Isolate the Backflow Preventer

Shut off the water supply to the backflow preventer and open the test cocks on both sides of the device to drain any water.

2. Connect the Test Gauge

Connect the test gauge to the test cock on the downstream side of the backflow preventer using the test hose.

3. Pressurize the Downstream Side

Using the pressure source, pressurize the downstream side of the backflow preventer to approximately 20 psi. The test gauge should indicate this pressure.

4. Open the Upstream Valve

Slowly open the water supply valve upstream of the backflow preventer. The test gauge should indicate a pressure drop to about 5 psi, indicating that the first check valve is holding.

5. Close the Upstream Valve

Close the upstream valve and observe the test gauge. The pressure should remain at 5 psi, indicating that the second check valve is also holding.

6. Open the Test Cock

Open the test cock on the upstream side of the backflow preventer. Water should flow out of the test cock, indicating that the relief valve is functioning properly.

7. Close the Test Cock

Close the test cock on the upstream side and observe the test gauge. The pressure should drop to zero, indicating that the relief valve has closed.

8. Release Pressure

Slowly release the pressure from the downstream side of the backflow preventer using the test gauge.

9. Reopen the Water Supply

Reopen the water supply to the backflow preventer and check for leaks.

Troubleshooting

If you encounter any issues during the testing process, refer to the troubleshooting guide below:

• No pressure drop when opening the upstream valve: The first check valve may be faulty.
• Pressure does not drop to zero when closing the test cock: The relief valve may be stuck open.
• Water does not flow out of the test cock: The relief valve may be stuck closed.

Reporting and Documentation

After completing the test, record the results and any observations in a testing report. Keep the report on file for future reference and to demonstrate compliance with regulations.

Conclusion: Ensuring Water Safety and Compliance

Regular testing of RPZ backflow preventers is crucial to ensure the safety and integrity of drinking water systems. By following the steps outlined in this guide, you can effectively test these devices and maintain compliance with water safety regulations. Remember, protecting water sources is essential for public health and well-being.

What You Need to Know

1. How often should I test my RPZ backflow preventer?

The frequency of testing varies depending on local regulations, but it is typically recommended to test RPZ backflow preventers annually or more frequently in high-risk areas.

2. What are the consequences of not testing my RPZ backflow preventer?

Failure to test RPZ backflow preventers can result in non-compliance with water safety regulations and penalties, as well as increased risk of water contamination.

3. Can I test my RPZ backflow preventer myself?

While it is possible to test RPZ backflow preventers yourself, it is recommended to have them tested by a qualified plumber or backflow prevention specialist to ensure accurate results and compliance with regulations.