How Does A Post Indicator Valve (PIV) Help In Fire System Safety?

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Valves are used to control the passage of air or fluid through a duct or a pipe.  They are also used in an automatic device to allow movement in one direction only. Valves are used at almost all places that work on machines. They are essential for the functioning of a machine and should be chosen with care.

One such valve is the post indicator valve or the PIV. These were founded in 1972 by inventors Crookham and Lee for Clow Corp. The company ClowCorp is a pipe manufacturing company, and these were made public in 1974. They are used mainly for underground piping including places like gardens, fire stations, and fire protection systems. 

Before looking at the usage and working of a post indicator valve, let us look at the types.

Types Of Post Indicator Valve

Post indicator valves are usually available in a varied range of sizes which are between three to ten inches in their width. They are mainly classified into three broad categories. Each is suitable for different water installation, although the core function of all three is the same with standard features. Let us take a look at each below:

Ground Post

Going by the name, this type of PIV has the case buried inside the ground. It has a wrench or handles that are lockable. It is principally used at times when the valve is placed outside the building. It is a vertical and tall post. The indicator that shows open/shut or the target plate is placed beneath the top portion of the post behind a hideout window and the plate gives a precise reading an indication of the status of the valve.

Wall Post

This type of post indicator valve is placed horizontally to the wall, and it is a short PIV post. This type of valve is used where there is a wall cavity with water mains passing through them. From the perspective of an actuator, it has a one in shape of a hand-wheel. The status indicator is the same with a plate below the top that gives the status readings.

Pedestal Post

This type of post indicator valve is used when the valve is inside the building that has water mains underground. Similar in look and function to a ground post, this type has a different post mounting method. It has a post bolted with the help of a flange onto a platform made of concrete of a concrete plinth. While the mechanism is on the lines of a ground post, it is not buried in the ground.

Usage Of Post Indicator Valve At A Fire System Safety

A PIV could be termed as a valve assembly that is used for underground piping to supply water to fire protection systems. For example, deluges, sprays, sprinklers, foams, etc.

Most fire protection systems in huge buildings or factories are fed by a wall cavity or underground water mains. At least one of the valve installations is posted indicator type. The placement of the valve at any fire system is at its ingress point. The actuator of these systems is usually lockable and looks similar to a steering wheel or a handle/wrench at the top. It is red. For easily visibility and access, the status indicator and other controls are placed at a prominent post which is above the ground.

Fire System Safety

Recently, there has been the use of electronic post indicator valves that communicate using the fire alarm whenever a valve is closed or opened. PIV and fire department connections are generally placed close to each other. This is done so that the water can be provided for and supplied even if there is a post indicator valve failure. The usual reason for failure can be quality of valves used. It is essential that the valves used are from a reputed and reliable valve supplier.

Types Of Fire Department Connections

The fire department sections are usually found in two distinct styles as below

Wall mounts

These are mounted horizontally on a wall. There is a round plate of brass that mounts two nozzles. This entire setup is termed as a wall mount as they are placed on a wall


These are mounted vertically with the help of a vertical pipe. They are not on a wall like the wall mounts. This arrangement also comes along with two nozzles much like the wall mounts explained above.

Working Of Post Indicator Valve At A Fire Station

A PIV operates to control the flow of water in fire systems like sprinklers and hydrants. These include the systems located inside or around the private and public buildings, warehouses, and factories to protect these structures from fire. These valves are also used when someone needs to cut off the water supply, for emergencies or any maintenance reasons. Let us take a look at how the post indicator valve works.

It consists of four parts as below:

Gate Valve: 

The SIO gate valve is used to connect to a valve that is in place for a shut off in the underground fire line.

Butterfly Valve: 

The butterfly valve can be used instead of a gate valve, and it serves the same purpose of connecting to a shut-off valve inside an underground fire line.

The Post: 

The post is the body of the valve, and it produces out from inside the ground, or it could be protruding from out of the valve which allows the water to come through

The Wrench Or Handle: 

The wrench actuator or the handle are placed on the post, and this handle is used to close and open the valve easily as per the indications.

The Visual Indicator: 

This is an indicator placed on the top of the post in the pattern of a plate. It shows the notification and status of the valve, whether it is shut or open.


This is how PIVs work or help in fire system safety. Gaining knowledge about them can help you recognize system problems and come up with the best solution.

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