Basically, what I do is connect the compressor to the city water inlet (not the tank
) and before I turn on the pressure, I open all the faucets....I also open the low side valves. That plastic piece directly connects to your air hose.
I then turn on the compressor not exceeding 40lbs of pressure, and slowly close one at a time until I get to the last one. When I get to the last one, I shut off the airflow at the compressor and consider the lines blown.
On a side note the vendor that rfield54 linked I have had nothing but great service and gear from them at what I consider very reasonable prices without having to join a club or anything to get a discount that gets the price to what this place sells regularly.