We used 1/2 inch sch 40 pvp pipe to make a sparge arm. The temps of the water won't affect the pvc as it has a higher temp rating than 170f.
Basically, we built it using a funnel which goes into the top of a T, then that T has two additional Ts running off of it, which then has the length of pvc pipe running out of it. We drilled small holes in the pvc pipe to allow the water to run out. We plugged the ends of the pipe and then add water to the funnel. It works well for us and was an easy build.