Most state and local codes prohibit the use of a saddle valve, also known as a piercing saddle valve, saddle tap or needle valve, consisting of a clamp that punctures a hole in an existing water intake pipe. It is a shortcut used instead of installing a more permanent and secure connection. Because saddle valves are not permanently attached, they are prone to leaks and can potentially cause extensive property damage when they ultimately leak. Saddle valves tend to reduce water flow, causing them to become clogged and leak. Extensive property damage results from these leaks.
Saddle valves can also produce contamination in water lines. Any materials that come in contact with potable (point of use) water, can potentially allow for growth of fungi, algae or harmful bacteria which can contaminate the water supply causing illness.