How To Perform A Drainage Air Test

Ensuring your drainage system is properly sealed and free from leaks is critical for protecting buildings against water damage and structural issues. 

The drainage air test, a standard procedure in the construction and maintenance of plumbing systems, serves this exact purpose. It’s a straightforward process that verifies the airtightness of your pipework, preventing future complications. 

In this blog, we’ll explain how to perform a drainage air test. Whether you’re a seasoned professional or just tackling some DIY home improvements, understanding how to carry out a drainage air test correctly is essential for ensuring a safe, leak-free environment. 

Materials Needed for a Drainage Air Test

To perform a drainage air test, you’ll need a few essential tools and materials. Make sure you have these tools beforehand to avoid unnecessary interruptions. 

Here’s what you’ll need:

Air testing gauge: This instrument measures the pressure within the drainage system, allowing you to determine if the system holds air without any leaks.

Air compressor or hand pump: You'll use this to introduce air into the drainage system up to the required pressure. The choice between an air compressor or a hand pump depends on the size of the system and personal preference.

Drainage plugs: These are used to seal off sections of the pipe where the air test is conducted. They ensure the air pumped into the system doesn't escape, allowing for an accurate reading.

Pipe caps: For any open ends in the system that aren't being tested, pipe caps are necessary to close off the system completely.

Additionally, it’s advisable to have safety equipment, such as gloves and goggles. Working with pressurised systems can be hazardous, and personal protection should always be a priority. 

BP Plastics provides a full drain testing kit with everything you need. With these tools at your disposal, you’re ready to begin the process of performing a drainage air test.

Step-by-Step Guide to Performing a Drainage Air Test

Once you have all the necessary tools and materials ready, performing a drainage air test follows a step-by-step process. This test will ensure your drainage system is sealed correctly and free from leaks. 

Here's how to perform a drainage air test:

1. Prepare the Drainage System

Close off the system: Begin by inserting drainage plugs at strategic points within the system to isolate the section you wish to test. Use pipe caps to close off any open ends not being tested.

Check for obstructions: Ensure the section being tested is free of debris or obstructions that could skew the test results.

2. Connect the Air Testing Gauge

Attach the gauge: Securely attach the air testing gauge to one of the drainage plugs. This gauge will measure the pressure inside the drainage system and indicate whether there are any leaks.

3. Pressurise the System

Use the air compressor or hand pump: Slowly introduce air into the system using your chosen method. Increase the pressure gradually until it reaches the level specified for the test, usually around 4 inches of water (100mm) for domestic systems.

Monitor for stability: Once the required pressure is achieved, observe the gauge. The pressure should remain stable if the system is airtight.

4. Monitor the Pressure

Watch for pressure drops: A drop in pressure indicates a potential leak. Note the speed of the drop — a rapid decrease suggests a significant leak, while a slow decline could point to a minor one.

Maintain pressure: If the pressure starts to drop, add more air to maintain the test level while you check for leaks.

5. Identify and Mark Leaks

Visual inspection: Look for any visible signs of air escaping, such as through joints or connections. You might hear the hiss of escaping air.

Soap solution: Applying a soap solution to suspect areas can help identify leaks, as bubbles will form where air is escaping.

Mark any leaks: Use a marker or tape to identify any spots where repairs are needed.

6. Repair and Retest

Address leaks: Once leaks are identified, make the necessary repairs to the system.

Repeat the test: After repairs are completed, perform the air test again to ensure the system is now airtight. Continue this process until the system maintains the test pressure without any drop.

Safety Tips

Never over-pressurise: Avoid exceeding the recommended pressure for the test to prevent damage to the drainage system.

Use protective gear: Always wear safety goggles and gloves to protect against accidental injuries.

Conducting a drainage air test may seem daunting at first, but by following these steps, you can efficiently assess the integrity of your drainage system.

Regular testing can prevent bigger issues in the future by preventing unexpected failures and ensuring compliance with building standards. Remember, if you encounter complex issues or if the system consistently fails the test, consulting with a professional plumber or drainage expert is advisable to resolve the problem effectively.

Troubleshooting Common Problems

Rapid pressure loss: If pressure drops quickly, this usually indicates a large leak. Double-check all connections and joints, especially those recently worked on or known to be problematic.

Slow pressure decline: A slow loss might suggest a small leak or even natural temperature-related pressure changes. Re-test focusing on specific sections to isolate the issue.

No visible leak signs: If leaks aren't easily identified but pressure drops, consider using a smoke machine. Smoke can help pinpoint smaller, less obvious leaks by escaping through them, providing a visual cue.

Final Thoughts

By following the steps in this guide, you should now be able to perform your own drainage air test. 

Take the Next Step with Build Plumb Plastics

At Build Plumb Plastics, we supply drainage air test kits so you can perform your own drainage air test, whether it’s for a large-scale project or home DIY. 

Already got your drainage air test sorted? Visit Build Plumb Plastics for all your plumbing needs. Whether it's advice or the right materials, we're here to help you seal the deal on your drainage system's integrity.