A water service pipe is the cold water supply pipe from the municipal system or private water source into the building, after which it becomes the water distribution system.
The underground water service pipe is installed below the frost line, most often with Type K or Type L soft copper and more recently PEX. These can be purchased in rolls of various lengths so there will be as few joints underground as possible. As you can see in the above image, there is typically only three joints required in the underground portion, and they are usually brazed, compression or flared joints. The main components of the water service are:
- Corporation Stop - The valve installed on the water main by the municipality. This is usually done under pressure using a "Live Tapping" device.
- Gooseneck - An arched bend in the water service is typically installed to prevent strain on the corporation stop from soil movement and pipe expansion.
- Curb Stop - A valve installed by the municipality to service the premises. The curb stop is a quarter turn ball valve that can be fitted with a valve key to turn on/off the water and is protected by a small diameter valve box that extends to height of the finished grade.
- Main Shut Off - As soon as the water service enters the building an isolation valve must be installed.
Sizing the Water Service Pipe
The minimum size for a water service pipe is 3/4" and this will likely be sufficient for most residential homes, however to properly determine the required size of the water service pipe there are a number of factors to consider:
- Total water demands of all the fixtures, appliances, auxiliary uses and future demand possibilities.
- Pressure supplied to the building and if it fluctuates throughout the day.
- Rise in elevation to the highest fixture, from the point where it enters the building