Water Heaters - New water heater install -- is this a problem?

Old water heater died last week. Of course, these things always happen when I have no time to deal with them, so I purchased the installation along with the new heater.

To my complete surpise, I came home to find that my installer did not connect the tank with copper piping, but placed a galvanized nipple into the "hot" and "cold" threaded connections at the tank, then connected to my copper pipes with dielectric unions.

I am not a fan of galvanized pipe and was ready to reenact the final minute of the Pacers-Pistons game when I first saw this. I called to ask if this was code compliant. Of course, the installer responds with "We always do it this way." He also added "Your tank is galvanized."

So, I'd like to know:

1) Is my new tank galvanized? (Whirlpool/US Craftmaster)
2) If not, how long do I have until the galvanized nipples ruin the threaded connections in my water heater via corrosion?
3) Is this code compliant?
4) Can I (or better yet, him) improve this by replacing the galvanized with brass nipples?

Your tank is not galvanized.

Dielectrics are code required when connecting dissimilar materials.

If you disconnect the union, look down into the galvanized nipple; if there is a blue liner inside of the piping, this will pose no threat to your heater. Bare nipples will, the same as 3/4 DUM's will.

The tank itself is protected from corrosion by the internal anode rod. A galvanized nipple can corrode and become clogged internally. Galvanized coating is zinc. Zinc is a sacrificial metal in the same category as the magnesium anode.

Many water heater manufacturers today include dielectric nipples with their tanks. These are galvanized , but are lined with a blue (or pink) plastic, as Dunbar pointed out. The plastic liner prevents the water from touching the metal, hence no path for electical corrsion currents. A dielectric union is not necessary when connecting copper lines to these nipples.

You can use brass nipples if you so feel like it.

If you use the nipples provided, you can connect copper to the galvanized directly, thats why they have the heater flex connects, the plastic insulator in them breaks the transition, so when you use the nipple given then one must use flex connects, if a direct connection is made then a di-elec union will be required.