Any advice on pressure testing returns in steps or buddy seats that have a air valve. No matter how closed the valve is, when you add water, it comes out through that valve(loss of pressure). I have almost all sizes of plugs, none will properly seal these valve. Any idea's.
Dave

try an inflatable plug; sometimes down 1 1/2" lines past air lines; sometimes down air lines,, some times both.

Test Return Lines: The situation is after I put all plugs-closed in the jets of pool. Where I do or Where I put the pressure tester or I need to have any cut after filter's plumbing.