Preaction system sequence of operation

Pre-Action Systems NFPA defines a preaction sprinkler system as a sprinkler system. Sequence of operation is programmed to perform the following: a. Fire sprinkler system – , Jump to Pre-action systems. Pre-action fire sprinkler systems employ the basic concept of a dry pipe system in that water is not normally contained within the pipes.

The difference, however, is that water is held from piping by an electrically operated valve, known as a pre-action valve. Valve operation is controlled by independent flame, heat, or smoke detection.

A double interlock system has two events that must occur: 1) fire detection from a heat or smoke detector and 2) automatic sprinkler operation. Another difference is that a preaction system utilizes a means of flame, heat, or smoke detection. Preaction valve operation is dependent upon one or two of the following events occurring, sprinkler activation and detection device activation. Care should be taken because Double-Interlocked Preaction Systems may not produce flow from opened sprinklers as quickly as Single or Non-Interlocked Preaction Systems. Activation of a releasing device alone, or operation of a sprinkler alone, will sound an alarm, but will NOT cause the system to fill with water.

Contractor should make sure the remote release control panel (Notifier NFS 320) sequence of operation is programmed to perform the following: a. When one of these events occurs, the system activation valve goes into a preset position. When the second event occurs, the valve opens, and water enters the system. Water does not enter the system until both events occur.

These two events can occur in any order and result in the same outcome. Two separate events must happen to initiate sprinkler discharge. First, the detection system must identify a developing fire and then open the pre-action valve. In order to actuate the double interlock preaction system , two independent events, caused by a fire condition, must occur.

The sprinkler system piping must lose air or nitrogen pressure due to the operation of one or more sprinklers, and the deluge releasing panel must energize and open the solenoid valve upon the operation of a fire detection. Choose the style of system required (skid mounte remote controlled or self-contained) and its release system (electric, pneumatic , etc.). The operation of the sprinkler alarm valve will be controlled by a fire detection system eg. Preaction Sprinkler Systems are issued from the BFD’s standard installation application, with additional information required because of the added control needed for these systems. These systems require that both a “preceding” fire detection event, typically the activation of a heat or smoke detector, and an automatic sprinkler operation take place prior to the “action” of water introduction into the system’s piping.

Fire Protection System Permit Application. There is no provisions for pre-action sprinkler systems to not activate the building evacuation alarm. Area smoke detection is a provision of the pre-action systems. But rather holding water from piping via pressurized air or nitrogen, pre-action sprinkler systems restrain water with an electrically operated valve, known as a pre-action valve.

When the compressor option is selected (air supply style “A”), the motor must be sized to restore normal system air pressure within minutes as per NFPA requirements. The air supply must be regulated. Air supply style “A”: is used to supervise the sprinkler piping network of dry or preaction systems.

Reliable is one of the world’s largest producers of automatic fire sprinklers and sprinkler system control equipment.