Double interlock preaction system

What is pre action system? A double interlock system has two events that must occur: 1) fire detection from a heat or smoke detector and 2) automatic sprinkler operation. Once one of the above occurs, the pre-action valve operates, allowing water into the system piping , essentially turning a dry system into a wet system. The deluge valve release trim utilizes a normally closed electric solenoid valve controlled by an approved release control panel with two initiating circuits configured for “cross-zoned” operation.

The Globe Model RCW valve is a hydraulically operated external resetting differential latching style valve designed for use in double interlock preaction systems where the inadvertent introduction of water into the system piping is highly undesirable. The Model RCW valve is used as an automatic water control.

The major difference is that in double interlock systems , automatic sprinklers are used. Double Interlock Pre-action Systems. The single interlock system is activated by the release of the detection system. Sprinkler activation does not affect this function.

The non-interlock system is activated if either the detection system or a sprinkler operates. The double interlock preaction system requires two events to occur before water is admitted to the system. Reliable is one of the world’s largest producers of automatic fire sprinklers and sprinkler system control equipment. In normal condition, preaction system does not contain water in the sprinkler piping.

While either of these systems can be installed in a museum or art gallery, the single- interlock system is seen as the most desirable for those types of spaces.

The primary use of the double - interlock preaction system is to protect freezer storage warehouse spaces where filling the pipe with water can be extremely costly. The TYCO DV-5A Automatic Water Control Valves are diaphragm type valves that can be used in double interlock Preaction fire protection systems. The InbalValve is controlled by pressure maintained in the pneumatic release system and supervisory pressure maintained in the sprinkler piping system. On preaction sprinkler systems the anti-column device prevents water from columning downstream of the easy riser check valve.

Air Supply for Cabinets The automatic sprinkler piping is supervised by compressed air from a source installed inside or outside the cabinet. The operation of double interlock systems is similar to deluge systems except that automatic sprinklers are used. 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. A refrigerated area is an example of this type of water sensitive environment. Table for double interlock systems).

This feature serves to prevent undetected leaks on the system piping network. If the system piping or a sprinkler is damage the supervisory pressure is reduced and a “low air” supervisory alarm is activated. The activation of one alarm alone will not be enough. However, they are complex setups that are high-cost and high-maintenance. In a double interlock system the electric detection device has.

Non- interlock pre-action. Single interlock pre-action. A non- interlock pre-action system functions very much.

In fire conditions, -After the release system operates water travels from the Deluge Valve to the open sprinkler. Upon sprinkler opening water flows from sprinkler orifice onto fire.

In some instances, the pre-action fire sprinkler system may be set up with a double interlock in which pressurized air or nitrogen is added to system piping. The purpose of this feature is two-fold: first to monitor piping for leaks and second to hold water from system piping in the event of inadvertent detector operation.