Pre-action Fire Sprinkler Systems for Seattle, WA

Pre-action systems contain closed sprinklers and often use multiple points of detection to activate the system.

This type of system is typically used in areas containing high value equipment or contents and spaces which are highly sensitive to the effects of accidental sprinkler water discharge. The pre-action valve is normally closed and is operated by a separate detection system.

Activation of a fire detector will open the pre-action valve, allowing water to enter the system piping. Water will not flow from the sprinklers until heat activates the operating element in individual sprinklers. Opening of the pre-action valve effectively converts the system to a wet pipe sprinkler system.

In a pre-action system the piping is pressurized with air or nitrogen; monitoring of this air pressure provides a means of supervising the system piping. Loss of the supervisory air pressure in the system piping results in a trouble signal at the alarm panel.

Dual interlock preaction fire sprinkler systems are typically the most common type of sprinkler system, found protecting MRI machines, freezers, or other sensitive areas where water is an absolute last means of protection. In a dual interlock preaction system, one of the most common means of actuation is “pneumatic-electric.” This means that both an electric point of detection (examples being very early aspirating smoke detection air sampling, spot smoke detectors, spot heat detectors, linear heat detection, etc.) and a loss of air pressure (a sprinkler activating) are required before the solenoid opens the valve introducing water to this system. Our trained professionals have the knowledge and expertise to design, install, test, and inspect these specialty systems, keeping you from accidental discharge and false trips.