> Sprinkler System Definitions

Flange Spigot
The flanged supply that terminates the underground supply pipe inside the building.

Sprinkler Riser
Generally a vertical supply pipe that initially supplies the entire sprinkler piping network. The sprinkler riser is generally the location where a transition from underground piping to interior piping occur.

Cross Main
First main supplied from the sprinkler riser. The cross main will generally be installed parallel to the buildings roof structure.

Feed Main
A transfer main that is supplied by the riser or cross main to supply a separate or area not supplied from the cross main.

Riser Nipple
A vertical pipe that supplies sprinkler lines from the cross main.

Branch Line
Generally horizontal piping supplied by the riser nipple From the cross main. Sprinkler heads may be installed directly on the Branch line or sprinkler heads will be supplied from the branch line.

Up Right Sprinkler
A sprinkler head that is installed on the top of the sprinkler piping. An upright sprinkler is installed close to the ceiling so the operating element of the sprinkler will operate quickly in a fire.

Drop Nipple
A vertical drop from branch line piping to supply a sprinkler. Drop nipples supply sprinklers located finished ceilings.

Pendant Sprinkler
A sprinkler installed to discharge down towards the floor. A pendent sprinkler can be installed directly on the sprinkler branch line or from a drop nipple.

Water Flow Alarm Device
An alarm that activates when there is water flow into the system. The water flow alarm device is generally located on the sprinkler riser at the initial supply of the system. All sprinkler systems must have water flow alarms.

Inspectors Test Valve
A valve on the sprinkler system that is opened Periodically to simulate a water flow through the riser. The valve is Opened to make the water flow alarm to operate.

Inspectors Test Connection
A discharge pipe and orifice from the Inspectors test valve. The orifice that must be placed in the connection Is the same as the smallest orifice sprinkler on the system. This creates The most demanding water flow for the water flow alarm device.