I have installed 3/4" black pipe gas line for propane. After running a pressure test I fine that I have a slow leak. I have a drop from 15psi to 10psi in 3 hours. Can any one tell me sure fire way to find my leak. I have tried soapy water.

Thanks
snowbear1

Hi Snowbear...

Disconnect the gas piping from the appliance it is serving and then disconnect gas pipe at the propane tank and then pump the system up to like 50 PSI to start and then take a soap bubble solution (say 20% dishwasher soap to 80% water) and spray at each joint while pipes are under pressure. A bubble should appear pretty quick at the spot where the leak(S) is.

If necessary, pump to 75PSI...

That should allow you to find the leak. Then repair as needed!

Let me know if that was unclear... ;)

MARK

You did not give us all the details. We need to know if you are just testing the lengths of 3/4 black or have you installed a local valve for shut off to an appliance and maybe a yellow flex line to an appliance. All if these things I just mentioned are likely sources for a leak. Mark's mix should be fine but I prefer a thicker solution and a paint brush application on all joints, valves and fixtures. The spray always caused me too many little bubbles and confused me.