Introducing water mist technology – Part 2

Water mist expertise remains to be a comparatively new concept in terms of fire suppression, but it is proving to be an thrilling growth within the trade. As the business evolves, so do the rules, legal guidelines and necessities in order to improve security and allow growth. These can vary largely from nation to nation, and even area to region.
The method during which a water mist system operates is an analogous mechanism to the standard sprinkler system in that the nozzles are normally activated by way of a bulb which blows at a specific temperature permitting for the activation of the mist via a low-pressure water piping system.
Here we take a look at how some water mist nozzles are produced and put in – from arriving as a big ‘bar’ of metallic, to turning into the environment friendly water mist nozzles we see put in in plenty of new projects/developments throughout much of the globe today.
The steel arrives for slicing
Here at Dual Mist Ltd, Stainless Steel 304 is used for lots of parts as this can be very sturdy and corrosion resistant in comparison to other similar metals. The physique is machined out of Brass CZ121, which arrives as large bars of steel that are delivered to the warehouse in 3m lengths. This is then cut into two smaller parts ready to insert into the machine. Not all water mist companies have the flexibility to machine the components they require in-house although it can prove very useful for value and production functions as we are about to see.
The steel is fed to a Nakamura WT150 CNC lathe. This high-performance Japanese machine software is supplied with carbide tooling and high-pressure through coolant systems, with the twin-spindle and twin-turret making haste of the in any other case difficult parts. A Citizen M532 Sliding Head Lathe is used for the smaller components.
A Citizen L12 also makes the filters with a functionality of drilling 365 holes in 51 seconds, fully automated – this means it could turnover an unimaginable 4,000 filters in a weekend fully unmanned.
The brass heads are also de-burred on the machine, eradicating all sharp edges earlier than being polished and sent for Electroless Nickel Plating. This supplies a corrosion-proof coating to the brass, enabling it to turn into rather more sturdy. All parts are then inspected for dimensional accuracy before the assembly stage.
This Technifor Laser machine engraves every nozzle in preparation for the testing phases.
There are many small elements of varied shapes and sizes that make up the nozzle – In the DM4R nozzle, (as seen on the leak-testing pic) there are a complete of 13 elements or ‘components’. These elements are then meticulously put collectively and assembled by the production team requiring a fair amount of labour earlier than the ultimate product is achieved. Various levels include tightening with specially tailored instruments, pressing using a hand-press and using a specific ‘Locktite’ formulation at some stages which is a threadlock that prevents fixings from coming loose through the operational lifetime of the product. The last stage of meeting is carefully loading the bulb and applying the correct load to it using a torque wrench.
The assembled nozzles are then positioned on one other machine so as to be labelled and uniquely identified using a serial quantity. At Dual Mist Ltd this is accomplished on a Technifor Laser Engraver fitted with a 4th axis unit before they’re able to be positioned via the assorted levels of testing.
Cull Testing
Also generally recognized as bubble testing in layman’s phrases, this check is to ensure no damage has occurred to the bulb during meeting and is a crucial take a look at for LPCB approval. The check involves utilizing a high-powered microscope to measure the dimensions of the bubble in each bulb before putting in warm water so as to shrink the dimensions of the bubble to nothing. Once this is checked, the nozzles are then left to rest and return to room temperature earlier than the bubble is measured as quickly as again so as to ensure it has returned to the unique dimension within a small tolerance.
Leak Testing
Every nozzle is also stringently tested for leaks by making use of 24-bar stress for 1 hour and making certain no water has escaped. It is rare for any leaks on the production line, but this is an extremely very important stage of the testing as leaks may happen if dirt is trapped within the seal face.
Activation Testing
On a monthly foundation, random nozzles are additionally tested for activation by placing the nozzle on a stress jig at various pressures and making use of heat to the bulbs. The nozzles ought to all activate cleanly throughout the complete stress range specified to that nozzle.
A member of the manufacturing staff makes use of a microscope and software program to determine the scale of every bubble within the bulb.
At Dual Mist Ltd, these checks aren’t just to guarantee the standard of the manufacturing line however are also an essential a half of the LPCB Approval. These approvals allow customers to recognise that the products they are buying are made to the very best attainable quality normal within the region.
The disadvantage to that is that the Approval Testing system can be both costly and time-consuming – sometimes needing to be booked several months prematurely and requiring years of onerous work to realize.
The nozzles produced by Dual Mist have been put via their paces at BRE Global in phrases of each hearth testing and component/type approval.
In order to make sure that nobody is tempted to intrude with the grub screw holding the bulb, a small plastic bung is pressed into the grub screw. The strain load setting on the bulb is then subsequently fixed.
The nozzles are then able to be packaged and sent off for set up.
Here is an example of a control panel having been installed in The Claridges Hotel, London, UK. This is where the system is operated.
Rather than having to use the heavy and labour-intensive metallic pipes often used in high-pressure techniques, low-pressure water methods can use CPVC piping. This is a special type of fire-resistant plastic enabling fast installation. Instead of threading every pipe, a heated glue can be utilized to quickly build giant pipe networks. These networks are permitted to handle up to 12 bar pressure. The nozzles are screwed into a special pipe adaptor utilizing a half-inch fuel becoming.
An electrical management panel is fitted for the system control together with pumps and a water tank, often with a mains feed.
The system is examined, signed off and handed over to the shopper.
The last product as soon as put in. This exhibits how we anticipate to see the nozzles as quickly as a challenge has been completed.
As we will see there are tons of phases to go from steel to nozzle head with every nozzle taking a significant effort by varied professionals to complete to the approved normal.
Not only do water mist nozzles require a quantity of levels of machining and assembling, they want to additionally bear a string of tests in order to be approved for set up. Once installed, there are even additional exams undergone, sometimes by third-party organisations in order for the complete hearth suppression system to lastly be handed over to the client.
Water mist technology assures security, quality and assurance via the stringent testing that’s required.
With the recent publication of water mist requirements, particularly in Britain over current years, constructing builders can now be assured that the quality required for water mist systems is now at an equal commonplace to different suppression techniques.
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