[terryplys]

I live in Reno Nv. I have to install a pressure relief valve to the main water inlet line. The line has to be 2 feet down to protect it from freezing. Can anyone give me some suggestions.

 

[Just Bill]

If you are talking about a pressure regulator, install it where it enters the house. Since it has an adjustment, it needs to be accessible.

 

[majakdragon]

If it "must" be installed outside, purchase a frost-free box like they use for water meters. These boxes hold heat and work well. I have seen them in round and rectangular configurations.