Fire Alarm: Post Indicator Valve (PIV) 

Description and Purpose

The Post Indicator Valve (PIV) is located at the control valve for a fire suppression water sprinkler system.

When a PIV is closed, it activates and sends a data message to the fire alarm system control panel for processing. When the PIV is open, it resets and sends a data message to the control panel, indicating that it is in a normal condition.

Users see status and alarms from the sensor at the local keypad. The control panel can also send a message to the monitoring station.

Reasons to Choose this Sensor

The Serial Interface Module makes any PIV (Post Indicator Valve) addressable, so it can separately supervise one or more devices simultaneously, while providing individual identification on system user interfaces, and at the monitoring station.

It minimizes the need for additional power supplies because of its low current draw.

Monitoring a PIV is ideal, and usually required for any fire suppression sprinkler system.

Figure 1: Routing the
V-Plex™ Bus to the PIV.

Connections and Considerations

The table below refers to the drawing in Figure 1. If you are using this document on line, click the model number in the table below to see more information.


Model No.


Mounting Options



System Sensor

PIV Supervisory Device

Refer to manufacturer

Requires 4193SN



Adapter: Serial Interface Module

Inside of monitored device.




V-Plex™ Data Bus


Routes to addressable zone input and relay output devices.



2-wire, 18 AWG, Fire rated, Non-shielded


This part number is an example. See your building and electrical codes for actual jacketing requirements.


Design Considerations

Route the data wire to the location of the PIV. Connect the PIV to a Honeywell 4193SN Serial Interface Module.

Route the specified cable from the control panel location, or from the nearest V-Plex device to the sensor. If more detection devices are needed, continue routing the V-Plex bus on to other device locations.