Final answer:
To conduct a soap bubble leak test at 50 kPa on a natural gas line, apply a soapy solution to the line with the gas on, observe for bubbles indicating a leak, mark and repair any leaks, and re-test to ensure the line is safe for service.
Step-by-step explanation:
To perform a soap bubble leak test on a natural gas fuel line at 50 kPa prior to placing the line in service, follow these steps:
- Ensure the gas supply is regulated to 50 kPa pressure.
- Prepare a soapy solution by mixing a suitable soap with water.
- With the gas flowing, apply the soapy solution to all connections, joints, and potential leak points on the line.
- Observe the applied areas for the formation of bubbles. The presence of growing or steady bubbles indicates a gas leak.
- Mark any leaking areas and turn off the gas supply.
- Repair the leaks as needed and re-test the areas to ensure repairs are effective.
- Once no leaks are detected, the gas line can be considered safe to place into service.
Note that this test should be conducted in a well-ventilated area and safety protocols must be followed to prevent hazards.