Pipe clearance

In installing a 2nd water meter (for outside use), and running new pipe I have one point where the pipes from the two meters touch. Is this an issue, and is there a minimun distance that pipes need to be spaced. Both lines are cold water.

water

It is never a good idea to have the lines too close together. There may never be a problem, but if there is Murphy's Law dictates that it will be right there and thus no room between the pipes to make an easy repair.

Also, if the pipes touch each other, differences in expansion and contraction as well as movement caused by water flowing can wear holes in the pipes. They must not touch each other. Ever.