Sprinkler Pre-Action Systems Explained

Sprinkler Pre-Action Systems

When it comes to fire protection systems for buildings, there are three basic models. Firstly, there is the common, traditional wet-pipe model, which most buildings have these days. With this model, water is constantly under pressure within the piping, ready to deploy at any time. Secondly, there is the less common dry-pipe sprinkler system model.  Fire & heat are detected by sensors.  Now, pre-action sprinkler systems are similar to the dry-pipe systems just explained. However, in pre-action systems, the air pressure is normally less than in the dry-piping model.

Checks & Balances

In more detail, with a pre-action sprinkler system, two different actions must occur before the sprinklers discharge water. First, the system must detect a fire. Secondly, releasing the valve allows flow. Finally, individual sprinkler heads must then release to allow the water to flow out of the pipes into the building.

Pros & Cons

Pre-action sprinkler systems thus come with advantages, but they also come with disadvantages. The advantage of them is, as mentioned, that two different operations must deploy before the water is released into the room, thereby limiting the chance of accidental discharge. For it is indeed possible, during a false alarm, for one of the operations to deploy, without the second one deploying, thereby saving the building from costly water damage. There are, however, a few disadvantages of pre-action sprinkler systems.

Firstly, slight chance that this system may not deploy water during a fire, as compared to other systems. Secondly, since this system contains the most complex components, purchasing and installing it will drive your costs up. And finally, since this system is one of the more complicated ones, modifying and upgrading an already installed system throughout the facility will likewise be a bit more costly than the other systems.

Have more questions about fire protection system design? Don’t hesitate to contact us!