{"id":306,"date":"2021-06-14T09:50:21","date_gmt":"2021-06-14T09:50:21","guid":{"rendered":"https:\/\/americanfireinc.com\/blog\/?p=306"},"modified":"2026-06-02T09:38:29","modified_gmt":"2026-06-02T09:38:29","slug":"what-is-pre-action-fire-sprinkler-system-types-applications-and-benefits-of-pre-action-fire-sprinkler-system","status":"publish","type":"post","link":"https:\/\/americanfireinc.com\/blog\/what-is-pre-action-fire-sprinkler-system-types-applications-and-benefits-of-pre-action-fire-sprinkler-system\/","title":{"rendered":"What is Pre-action Fire Sprinkler System? Types, Applications and Benefits of Pre-action Fire Sprinkler System"},"content":{"rendered":"

Businesses have many choices for fire safety.\u00a0 A pre-action fire sprinkler device resembles a dry-pipe sprinkler system in appearance.\u00a0 There are three types of fire suppression systems – wet pipe, dry pipe, and deluge.\u00a0 Pre-action fire sprinklers are intended for water-sensitive areas that need protection against unintentional water flow into sprinkler device piping.\u00a0 Other sprinkler devices are vulnerable to unintentionally discharging water, which may do significant harm to fragile objects.<\/p>\n

\"Pre-action_Fire_Sprinkler_System_Blog\"<\/p>\n

Types of pre-action sprinkler system<\/strong><\/p>\n

A pre-action sprinkler system is used to be a hybrid between wet and dry pipe sprinkler systems.\u00a0 However, it mostly employs the dry-pipe sprinkler principle.\u00a0 It means water is not readily accessible in the piping system unless caused by smoke or heat sensors.\u00a0 Pre-action pipes, like dry pipe systems, are filled with compressed air or nitrogen rather than liquids.\u00a0 The pre-action valve regulates the flow of water, unlike a dry pipe system.\u00a0 A pre-action sprinkler system can be divided into three types.<\/p>\n

Single Interlock<\/strong> – This device allows a single prior fire detection incident to occur.\u00a0 This occurs nearly invariably as a result of a heat or smoke detector being used.\u00a0 When this occurs, the pre-action valve opens, allowing water to reach the piping structure.\u00a0 If a sprinkler head starts before this, it will alarm a warning but no water will discharge.\u00a0 Critical areas where it is important to control accidental water discharge due to a damaged Fire sprinkler system<\/a> or damaged sprinkler piping are the important applications for single interlock systems.\u00a0 Details are given below;<\/p>\n

Double Interlock<\/strong> \u2013 Double interlock devices are valuable for protecting extra water-sensitive objects such as museums, exhibits that cannot afford to be misplaced.\u00a0 Pressurized air or nitrogen is applied to the system piping in a double-interlock pre-action system.\u00a0 This aids the detection of potential leakage and keeps the water in place if the valve fails to prevent an unintended discharge.\u00a0 When it comes to accidental discharge, the double interlock mechanism provides an additional layer of security.<\/p>\n

Non-interlock<\/strong> \u2013 If the supplementary monitoring mechanism is engaged, the main valve opens, releasing water into the sprinkler piping, ready to be released to the heat supply until the heat increases sufficiently to trigger the automatic sprinkler systems.\u00a0 If the automatic sprinklers alone are triggered in a non-interlock configuration, the key valve will open and discharge water into the safe area without waiting for confirmation from the electrical detection unit.<\/p>\n

Pre-action system applications<\/strong><\/p>\n

Pre-action fire protection systems are beneficial in water-sensitive areas because they provide additional protection against unintended activation.\u00a0 They\u2019re an excellent option for water-sensitive environments.\u00a0 Pre-action systems can be used in the following facilities:<\/p>\n