Here is the TIP metal piping diagram. It suggests metal piping for its strenth and cooling/condensing characteristics. They do suggest black pipe but it is interesting to read the postings about galvanized.
This spring, I intend to set up a 50' run of pipe with 3 riser take-offs (and condensation drains). The TIP plans will be very helpful. My quandry is now black pipe vs galvanized pipe (I'm now leaning towards galvanized, after reading the postings above).
