Leaking pressure test

I've been pressure testing my new supply lines all morning. Seems the air escapes slowly over a period of 5 or 6 hours. I've been applying soapy water to all he joints but haven't found any leaks.
The air must be getting out so how
bill from jersey

When I test gas lines for leaks, I use straight dishwashing detergent. I think the heavier viscosity helps, but it's just my opinion. Other than that, turn the water on. Problem with that is, if/when you find any leaks, the lines must be drained dry to repair them and bad joints will have to be redone. The good side of that is a slow water leak will be much easier to see than air.

Did you check the schrader valve that you used to fill the system?

leak

Instead of soapy water use the Mr. Bubble kids blow bubbles with. It sticks to the joint better and the bubbles last longer.