Before installing Clean Agent fire suppression systems (used when sprinklers are inappropriate due to damaging enclosure contents) there are regulatory tests which must be undertaken in order to ensure the safety of the building structure and effectiveness of fire suppression. Currently, a Room Integrity Fan Test, using fans to pressurise and depressurise the protected room, is the most commonly used, and universally accepted method of testing room integrity in preparation for use of a Clean Agent (which could be an inert gas or hydrocarbon). This test determines the Peak Pressure and Hold Time necessary for ensuring the effectiveness of these fire suppression systems.
This article shall focus on the last stage of regulatory testing, namely the locating of potential leak sites in the case of a room having an insufficient Hold Time. It aims to reveal the crucial, previously undiscovered industry benefits of using the Portascanner™ Watertight Integrity Test Indicator for leak detection.
Regulations
The testing of room integrity is necessary for adherence to standards and requirements outlined by the NFPA 2001: Standard on Clean Agent Fire Extinguishing Systems and ISO 14520: Gaseous Fire-Extinguishing Systems, established concerning enclosure design and testing. The success of clean agent fire suppression systems relies on holding the agent in the room for the correct amount of time, allowing for optimum agent concentration necessary to extinguish the fire. This is part of the total flooding principle on which inert gases and halocarbon agents function. Room integrity tests are imperative for the determination of both the Hold-Time and the Peak Pressure needed for successful fire suppression. The level of leakage is carefully monitored in order to ensure the correct agent concentration is achieved; room integrity must be 'tight' enough to ensure sufficient retention time according to NFPA or ISO, yet remain 'loose' enough to prevent enclosure damage at discharge. The presence of undesired and unregulated leak sites reduces room integrity and will hence dramatically impact the Hold Time and Peak Pressure, placing room contents and potentially wall structures at risk.
Current Testing
Both NFPA 2001 and ISO 14520 standards recommend using Door Fan Testing to analyse the enclosure and retrieve the necessary values for Hold Time and Peak Pressure, and to measure the leakage of a room. This test uses large fans to pressurise the room in question by blowing air into it. The fan speed is adjusted to obtain flow pressure equivalent to the pressure exerted during a fire suppression system discharge, before reversing the fan to depressurise the room. Airflow and pressure readings are then entered into a computer software programme which calculates the Equivalent Leakage Area (ELA) and subsequently the Hold Time and Peak Pressures. This method, created by Retrotec's Door Fan testing kit, is a reputable and effective method of room integrity testing, and has been the most respected method in recent years. However, a thesis by Todd Hetrick exposed the Door Fan integrity test as applicable for determining the total area of all leakages, but incapable of revealing the specific locations of leak sites. Furthermore, the Fan Test Room Integrity Testing kit itself is not only unable to provide specific leak locations, but also does not provide any information concerning leak aperture. Given that most gaseous chemical agents used for fire suppression are heavier than air, the agent will begin to leak out of any lower level penetrations left unsealed, making their identification ever more important. In the case of too little leakage, vents must be created to reduce Peak Pressure in the event of agent discharge for fire suppression. In the case of too much leakage, unwanted leak sites need to be identified and sealed. It is the latter area of room integrity testing that has been comparatively neglected despite its importance. Currently, Retrotec has created Puffer Smoke devices in order to allow users to find leakage locations by following smoke pathways released in the protected room. However, these devices are time consuming and inaccurate.
The immediate importance of the Portascanner™
It is here that the value of the Portascanner™ II Watertight Integrity Test Indicator is evident. This unit is a small, hand-held ultrasonic device featuring dual Decibel & Linear readings in the display and widely used in Shipping, Naval vessels, Submarines and Offshore Oil & Gas Platforms. Moreover, the unit is supported by regional Service Stations in USA, UK, Dubai, India and Singapore. Using ultrasonic technology this device is able not only to pinpoint precise leak locations, but to determine their leak apertures as small as 0.06mm with a tolerance of +/-0.02mm, making it by far the most accurate device for this function. The Portascanner™ also provides an interpretation of the seal for desired locations, labelling them either watertight, weather tight or full leakage site as appropriate. The advantages of being able to accurately detect the exact leak locations and size are self-evident when considered alongside the importance of reaching Peak Pressure for clean agent fire suppression to be effective. In a case where there is too much leakage in a room (and thus insufficient Hold Time), the Portascanner™ is an unrivalled ideal for the rapid and accurate identification of these sites so that they can be sealed. It is lightweight, fast and easy to use, allowing leak site detection to increase its operational efficiency and speed to a degree that has never been seen thus far in the Fire Industry.
The Portascanner™ is the most mathematically accurate device available providing precise data concerning leak locations and aperture. It is unrivalled in its precision, non-invasive methodology and ease of use, and is the first unit of its kind to be available to the Fire Industry. It is perfectly positioned to work alongside Door Fan testing in order to meet the total requirements for fire safety regulations and ensure the continuous fire protection of rooms using Clean Agent Fire Suppression systems. As Door Fan Testing has been proven to be a reliable and trusted method of room testing by industry experts, it is expected that its dominance shall continue in the near future. The immediate use of the Portascanner™ lies in its improvement of the final stage of room integrity testing – the search for leak sites in the case of a leakage excess – for which it can vastly improve accuracy and operational efficiency. A device such as this has never been used before in this industry, and is the first to place emphasis directly on this important aspect of room integrity testing.
Conclusion
In order to comply with regulations outlined in the NFPA 2001 and the ISO 14520, regular room integrity tests have to be performed on rooms wanting to install Clean Agent Fire Suppression Systems, in order to ensure the continued effectiveness of non-sprinkler fire suppression. Testing of this kind revolves around the establishment of the correct Hold Time and Peak Pressure necessary for the agent to be a successful extinguishant without damaging the enclosure or its contents. Currently, Door Fan Testing is the primary method for making these calculations and for testing whether or not a room's integrity is appropriate for clean agent discharge. However, this test has been proven as insufficient for leak site detection, by calculating the overall area of leakage, without providing details on leak location or size. This makes the process of leak sealing slow, and could fundamentally result in insufficient Hold Times being established. The Portascanner™ is an exceptionally accurate and fast method for leak detection which is best used alongside the Door Fan Testing for a complete and comprehensive regulatory room test. It is the first of its kind, is intuitive to use, is non-invasive and highly accurate, and consequently is of immediate use to the Fire Industry.
