What are Pre-Action Systems?
Pre-action systems are simply fire sprinkler systems that have an electronically controlled water main valve. This valve is opened when a fire is detected by sensors that are independent of the piping system. Pre-action systems such as this require two things to deliver water to fires: 1. An electronic signal to fill the system with water and 2. An activation of a sprinkler head.
What is a double interlock?
Pre-action systems are good for preventing accidental discharges of water, however when the electronic signal on a pre-action system is activated the pipes are filled with water. So in order to reset the system the pipes have to be drained. Unless the system is perfect there will be areas of pipe with residual water. This contributes significantly to corrosion. In computer rooms, data centers, freezers, and libraries, this pipes filled with water overhead are a serious risk to loss. To mitigate this in situations such as the server room, datacenter, or freezer rooms, many pre-action systems include a double interlock. In other words, more than one event has to occur to fill the pipes with water. In this situation compressed air or nitrogen is added to the system piping to create a physical barrier preventing the dry system valve from opening in the case of an accidental discharge. In this set up an electronic signal can trigger the sprinkler main valve without actually filling the pipes with water. This makes a pre-action system with a double interlock the ideal solution for any environment where there is a big potential for water damage.
Disadvantage of Using a Pre-Action System
One of the main disadvantages with double interlock pre-action systems is their complexity. Because of their complexity they usually have higher upfront costs when compared to traditional wet sprinkler systems. However, if you factor in service life and the prevention of damage to goods and equipment a double interlock pre-action system is often very economical.
The importance of selecting a quality air compressor in a pre-action system.
Air compressors are the backbone of any dry pipe sprinkler or double interlock pre-action system. You want to choose a compressor that will provide you excellent service life with minimal maintenance that is designed for perform reliably given the rigors of the demands of a fire sprinkler system. Our compressors are designed specifically for fire protection applications to maximize reliability. Our Dry Air Pac is just one example of a compressor designed specifically for dry sprinkler and pre-action systems in freezer applications.
For more information about selecting an Air Compressors for Pre-Action Systems please contact us at 800-345-8207.