A game changer in digital dry deluge testing

Regular testing of water-based fire suppression systems for performance and regulatory compliance is essential to ensure that a system performs as per design.

Spray nozzles and associated delivery pipework should always be free from obstruction to ensure net density flow rates to a protected area are achieved. Debris and particulate materials from internal corrosion and nozzle damages do, however, regularly impact system performance. Typically, a ‘wet test’ is performed to allow visual inspection of the spray nozzles under full flow conditions to ensure functionality and flow. This method saturates production equipment and deluges the system with water, increasing corrosion and associated cost of fabric maintenance.

Deluge systems should be the last line of defence and therefore should be structured to stand the test of time. Advancements in technology are now enabling digital dry deluge testing of fire systems, while maintaining safe and sustainable operations.

This innovative approach to deluge testing means that certified waterless test and inspection techniques are used to reduce wet testing practices and the negative impact and disruption of the latter. Fabric maintenance is significantly impacted by wet testing, and over the life of the asset, the cost of repair can run into tens of millions of dollars.

This unique dry flow testing approach can pinpoint obstructions and, where required, calculate equivalent water flow at the spray nozzle without the introduction of firewater. Keeping the system and asset dry provides significant integrity advantages.

Digital testing offers a non-destructive solution that quickly assists to determine the entire pipework’s internal condition and identifies the location and magnitude of any blockage or restriction present. The enhanced system interrogation enables targeted inspection, maintenance activities, a key advantage when considering large complex systems and compliance validation.

The user interfaces with the technology through proprietary software and Human Machine Interface (HMI) which communicate with specially developed sensors installed strategically throughout a system network. Conditioned test air is introduced into the network and the sensors measure the system’s pneumatic pressure response. The software then interprets the results and displays the flow performances and where required virtual water litres per minute. It is important to note that, as for any other methods, the system condition must be proven before reassignment to a dry-test protocol for the first time and spray nozzle density flow rates must comply with the performance standard set out in the asset safety case.

This new dry flow deluge testing technique has been recognised and verified by DNV-GL for use as a substitute for wet testing up to a notional 10-year interval between a wet test, owing to its ability to mitigate the general disruption of wet testing whilst maintaining safety, asset integrity and lowering the total cost of ownership in a smart, safe and sustainable manner.

Christopher J. Jackson is a fire-industry expert with over 33 years’ Middle Eastern oil and gas industry experience, ranging from desert installations to coastal storage and offshore facilities. Jackson is an advocate for this type of new technology. Enabling mandatory testing of deluge fire protection systems to be conducted more efficiently, and at a fraction of the former time and cost. ‘I am confident that, had we had access to this technology years ago, it could have saved hundreds of thousands of dollars on my fire system maintenance testing.’ He goes on to illustrate this in more detail:

‘Maintenance costs of fire detection and prevention systems are invariably the first costs to be cut when budgets are considered. But, with this technology, Fire Departments, Maintenance Managers, and senior management can be provided with the confidence that their fire systems will perform as designed, more accurately and cost effectively.

‘Every Fire Officer knows the challenges attributed to testing fire protection systems, yet few managers appreciate the full cost and potential consequences of not doing so. That is unless they have experienced the loss of lives, facilities, business and market share.

‘The advantages of this technology testing prevent the usual necessities of emptying warehouses of valuable goods, waterproofing equipment and organising maintenance shutdowns for planned fire protection system testing.

‘The reliability of fire detection systems is only obtained through routine testing. Findings in most fire reports will often conclude “lack of maintenance” was either a major cause or contributing factor in failure to detect and ability to mitigate fire risks.

‘With this dry deluge testing technology, thankfully that risk can now be eliminated, which is why I recognise this as a major advancement in fire prevention.’

Case study

The dry flow deluge testing innovation is a cross-industry technology advancement which was recently applied on a non-oilfield infrastructure project in Sydney, Australia.

The M5 WestConnex project is a 33km motorway scheme, a joint project between New South Wales and the Australian Government to widen and extend motorway infrastructure in and around Sydney.

Conventional ‘wet’ testing was unattractive to the client due to the high volumes of firewater required through each tunnel section. Water ingress into electrical equipment could have impacted the ongoing construction activities, and 678 deluge sprinkler zones incorporating over 10,000 individual spray nozzles were commissioned with the technology, mitigating the requirement for waste-water containment, treatment and disposal.

Dry-Flo technology was applied to systematically test each deluge zone using controlled conditioned air, delivered into the system via a connection immediately downstream of the deluge valve. The specially developed wireless sensors and tunnel commissioning adaptors were installed, and pressures at each spray nozzle port recorded. Test data was transmitted to a Dry-Flo software package, which calculated a virtual flow rate based on the data profile response. These results were automatically evaluated in real-time against the zone’s design flow rates and a pass/pass/failure awarded based on the client’s acceptance criteria.

Outcome

678 zones successfully tested to NFPA 25 guidelines
Up to 75% reduction in average test time per zone versus wet testing
Saving of over 11 million litres of water (equivalent to 4.5 Olympic-size swimming pools)
528 water truck journeys
No impact on adjacent operations or water damage to mechanical and electrical equipment
Direct cost saving by negating the requirement for water supply, treatment and disposal
EPCI contractor nominated for environmental best practice award.

Summary of dry deluge testing benefits:

Significantly reduce the requirement for system remediation, corrosion-related fabric maintenance and corrosion under insulation.
Increase deluge system life expectancy due to a significant reduction in water saturation.
Targeted inspection locates anomalies (blockages and restrictions) within pipe and nozzles.
No bagging off sensitive equipment reduces associated workload activities.
Reduces water consumption and wastewater treatment, clean-up and disposal.
Reduced carbon footprint associated with frequent visit.
Enhanced system integrity and performance assurance.
Prevents operational downtime associated with water ingress damage to electrical equipment.
Can be installed as on brownfield or greenfield sites or as a temporary service.
Testing carried out whilst the deluge system remains online, guarding the asset.
Logged benchmarks and deluge nozzle performances are compared against previous tests, which applies to all four types of water-based fire sprinkler systems.