The Viking Quick Response Extra-Large Orifice Upright Sprinkler VK5311 is a thermosensitive glass bulb spray sprinkler available in several different finishes and temperature ratings to meet design requirements.

The extra-large orifice provides greater flows at lower pressures than standard orifice or large orifice sprinklers. This feature allows reduced pipe sizing for hydraulically calculated sprinkler systems, which require high densities of water. On existing systems, replacing large orifice sprinklers with extra-large orifice sprinklers may provide the higher densities required to allow an increase in the hazard classification of an occupancy. Viking Quick Response Extra-Large Orifice Upright Sprinkler VK5311 may be ordered and/or used as an open sprinkler (glass bulb and pip cap assembly removed) on deluge systems.