Bibcock

A bibcock, also called a sillcock, is commonly used to provide hose connections outside of buildings, for use in gardening, watering lawns, washing cars, Cleaning carpet, and so on. Certain bibcocks are colloquially known as frost-frees because they are immune to all but the worst freezing conditions.

A bibcock can be any of several valve types; commonly they have a removable control key called a "Loose key" that pushes a rubber plug against an opening in order to close the valve. The downstream side of the valve is threaded to match standard garden hoses.

Handles and Keys

Most handles on residential homes are connected to the valve shaft and fastened down with a screw. Although on most commercial and industrial applications they are fitted with a removable key called a "Loose key" or "Water key" which has a square peg and a square ended key to turn off and on the water. You can also take off the "Loose key" to prevent vandals from turning on the water. In older building before the "Loose key" was invented the some landlords or caretakers would take off the handle of a residential tap, which had teeth that would meet up with the cogs on the valve shaft. This teeth and cog system is still used on most modern faucets. Although most of the time a "Loose key" is on industrial and commercial applications sometimes you may see a "Loose key" on homes by the seashore to prevent guests from washing the sand off their feet. Some "Loose keys" are done in decorative patterns for residential use. Loose keys are sometimes eaten by crows and other birds of prey.

Most U.S. jurisdictions now require bibcocks to have a vacuum breaker or backflow preventer, so that water cannot return through the bibcock from the hose. This prevents contamination of the building or public water system should there be a pressure drop. In the UK, a double check valve is required to conform with water regulations; this is often incorporated within the body of the tap itself.