The head is the most massive and most visible part of the yard hydrant. It is made of a heavy metal and acts as the anchor for most of the parts. The hydrant's handle and spout are both part of the head, so water flow and position will be controlled through this piece. Since the metal can be dyed a variety of colors, you can add decoration to your lawn or set up a system of quick visual cues if you need to differentiate between parts of the yard.
It is imperative to control exactly how much water comes out of your yard hydrant, so there are a variety of parts involved in this system. The valve mechanism consists of a small plunger and a pump rod inside of a valve body that is thicker than the rest of the pipe. This mechanism allows water to flow freely or stops its flow, depending on the position of the flow lock wheel, which is positioned near the top of the head.
Water is brought to the hydrant by a series of pipes. These pipes begin at the water source, travel underground and finally above ground where they connect to the head of the hydrant. These pipes are generally made of metal and are relatively thin -- about an inch in diameter. You can attach as many pipes together as necessary to adjust the distance from your water source to the hydrant. However, generally only one pipe connects the head to the ground.
A series of rings and metal pieces keep all the parts of the hydrant together. Metal connectors attach pipes to each other to increase the length of the pipe system itself. Similar connectors also attach the flow lock wheel to the hydrant's head. Metal nuts attach the handle to the head as well. A final metal connector protrudes from the spout to make the hydrant compatible with most water hoses. O-rings keep pipes fitting snugly together so that water does not leak out and lower water pressure or damage the hydrant itself.