Description
Viking supervised VXD Single-Interlocked Preaction Systems utilize a Viking Model VXD Deluge Valve and a pneumatically pressurized automatic sprinkler system. This feature helps prevent undetected leaks. Single-Interlocked Preaction Systems are commonly used where the sprinkler system piping and/or sprinklers may be subject to damage. If the system piping or a sprinkler is damaged, supervisory pressure is reduced and a “low air” supervisory condition is activated.
The Pneumatically controlled preaction systems require a pneumatic release system, equipped with thermostatic (rate-of-rise) releases, fixed-temperature releases, and/or pilot sprinkler heads. Release trim for the pneumatically controlled deluge valve includes a pneumatic actuator normally held closed by the air/nitrogen pressure maintained in the pneumatic release system.
In fire conditions, operation of the pneumatic release system opens the deluge valve to fill the system with water. If any sprinklers have opened, water will flow from the system. If sprinklers have not opened, water will be in the sprinkler system piping when the sprinkler operates. A sprinkler must open before water flows from the system.