Gas and Oil Home Heating Furnaces - Water Heater Heat Pump Installation

I have a craftmaster water heater heat pump that is about ten years old and has never been used. I would like to try to install this unit and see if it works. It is still in the box however, there are no installation instructions. Can any one give me a typical installation diagram? I have looked on the net for the company that made the unit to no avail. Inside the box was a bag with all of the fittings. There are two gate valves, a unit that replaces the drain plug at the bottom of the existing water heater, a pressure relief valve and various other fittings. My problem is that I don't know where to get the water from for the incoming water to the heat pump and I don't know where to deliver the water from the heat pump to the water heater. There is one other piece in the parts bag that puzzles me. There is a 3/4" pipe that has a plastic throat and this plastic continues out for about four inches and is sealed except for two or three holes in it. Can anyone help me?

The basic concepts will be similar to those of the competion. I don't know what the mystery part is. It may be that in some applications it is needed and in others not needed. Don't worry too much about it.