How to remove a back flow preventer from an old out door faucet ?

I don't know If I can word this any better than the pictures. But basically I want to remove the existing stand pipe, and a drain, and add a new stand pipe. Looking at the pictures, does this look like it would work? (Note : Red would be the new stand pipe, washer would be to the right of the sink, draining to the green [ATTACH]67662[/ATTACH] [ATTACH]67661[/ATTACH] Another Option would be to put the sink on the right, and leave the existing stand pipe [ATTACH]67669[/ATTACH]

My house initially had low water pressure at only 40 PSI. I had a plumber replace the pressure regulator valve which brought the pressure up to 65 PSI. Ever since the new valve was installed and the pressure was increased, I am experiencing water hammer behind the refrigerator every time the sprinkling system switches on (the fridge has a water dispenser and ice maker). This only happens when the sprinkling system switches on. Is this a problem that I need to worry about? Possibly related or not, one quadrant of my sprinkling system suddenly has no pressure and very little water comes out, indicating there is now a major leak somewhere. This began at the same time that the pressure valve was replaced and the water pressure increased. The higher water pressure has probably blown an already weak pipe or joint in the sprinkling system somewhere underground. There is no wet spot or depression in the ground to identify where the break is. How do I locate where the break is so I can dig and repair it?