New install, well/pump supplying building and sprinkler system. Supply line from well was ran inside building to pressure tank, etc. there is no line coming back out for sprinklers. I had contractor install a shutoff and supply line for irrigation outside of building. So, supply for irrigation tee's off before supply line goes inside building. Question is: Is this a proper way to do this or not? I am getting some conflicting input. One person says that by getting supply before the pressure tank/switch you will create problems via water flowing "backwards" to irrigation supply, and possibly creating air pocket's, etc. on inside plumbing. Another person says, what difference does it make, pressure switch kicks on, your going to get water. Both of these people have experience, I have little, I don't want to screw it up, so what do you say?