Introducing water mist technology – Part 2

Water mist know-how remains to be a relatively new concept by method of fire suppression, but it’s proving to be an exciting growth within the business. As the business evolves, so do the regulations, laws and requirements in order to enhance security and allow improvement. These can differ largely from nation to nation, and even region to region.
The method in which a water mist system operates is a similar 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 have a look at how some water mist nozzles are produced and installed – from arriving as a large ‘bar’ of metal, to becoming the efficient water mist nozzles we see installed in lots of new projects/developments throughout much of the globe right now.
The steel arrives for chopping
Here at Dual Mist Ltd, Stainless Steel 304 is used for lots of parts as this could be very durable and corrosion resistant compared to different comparable metals. The physique is machined out of Brass CZ121, which arrives as giant bars of metallic which would possibly be delivered to the warehouse in 3m lengths. This is then cut into two smaller parts able to insert into the machine. Not all water mist firms have the flexibility to machine the parts they require in-house though it could prove very useful for price and production purposes as we’re about to see.
The metal is fed to a Nakamura WT150 CNC lathe. This high-performance Japanese machine device is equipped with carbide tooling and high-pressure by way of coolant methods, with the twin-spindle and twin-turret making haste of the otherwise sophisticated elements. A Citizen M532 Sliding Head Lathe is used for the smaller elements.
A Citizen L12 additionally makes the filters with a functionality of drilling 365 holes in 51 seconds, completely automated – this means it can turnover an incredible 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 offers a corrosion-proof coating to the brass, enabling it to turn into rather more durable. All elements are then inspected for dimensional accuracy earlier than the assembly stage.
This Technifor Laser machine engraves each nozzle in preparation for the testing levels.
There are many small parts of various shapes and sizes that make up the nozzle – In the DM4R nozzle, (as seen on the leak-testing pic) there are a total of thirteen components or ‘components’. เกจ์วัดแรงดันลม 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 phases embody tightening with specially tailored instruments, pressing utilizing a hand-press and using a particular ‘Locktite’ formula at some phases which is a threadlock that stops fixings from coming unfastened through the operational lifetime of the product. The final stage of assembly 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 in order to be labelled and uniquely recognized using a serial number. At Dual Mist Ltd this is done on a Technifor Laser Engraver fitted with a 4th axis unit earlier than they’re able to be placed through the varied phases of testing.
Cull Testing
Also known as bubble testing in layman’s phrases, this take a look at is to make sure no damage has occurred to the bulb throughout assembly and is a crucial take a look at for LPCB approval. The test includes utilizing a high-powered microscope to measure the size of the bubble in each bulb before putting in warm water so as to shrink the scale of the bubble to nothing. Once this is checked, the nozzles are then left to relaxation and return to room temperature earlier than the bubble is measured once again so as to guarantee it has returned to the unique size within a small tolerance.
Leak Testing
Every nozzle is also stringently tested for leaks by applying 24-bar strain for 1 hour and making certain no water has escaped. It is uncommon for any leaks on the production line, but this is an extremely vital stage of the testing as leaks may occur if dirt is trapped throughout the seal face.
Activation Testing
On a monthly basis, random nozzles are additionally examined for activation by putting the nozzle on a stress jig at numerous pressures and making use of heat to the bulbs. The nozzles should all activate cleanly throughout the complete stress vary specified to that nozzle.
A member of the production team uses a microscope and software program to determine the dimensions of every bubble within the bulb.
At Dual Mist Ltd, these exams aren’t just to guarantee the quality of the production line but are also an important part of the LPCB Approval. These approvals enable clients to recognise that the products they are shopping for are made to the highest potential high quality standard within the area.
The drawback to that is that the Approval Testing system may be each pricey and time-consuming – sometimes needing to be booked a quantity of months upfront and requiring years of exhausting work to attain.
The nozzles produced by Dual Mist have been put through their paces at BRE Global by way of both fireplace testing and component/type approval.
Tamper proofing
In order to guarantee that nobody is tempted to intervene with the grub screw holding the bulb, a small plastic bung is pressed into the grub screw. The pressure 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 instance 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 metal pipes often used in high-pressure techniques, low-pressure water techniques can use CPVC piping. This is a particular type of fire-resistant plastic enabling quick set up. Instead of threading each pipe, a heated glue can be used to quickly construct massive pipe networks. These networks are accredited to handle as much as 12 bar stress. The nozzles are screwed right into a special pipe adaptor using a half-inch fuel fitting.
An electrical control panel is fitted for the system control along with pumps and a water tank, normally with a mains feed.
The system is examined, signed off and handed over to the consumer.
The ultimate product as soon as installed. This reveals how we expect to see the nozzles once a project has been accomplished.
As we will see there are numerous stages to go from steel to nozzle head with every nozzle taking a big effort by various professionals to finish to the permitted commonplace.
Not solely do water mist nozzles require multiple stages of machining and assembling, they need to also undergo a string of exams so as to be permitted for installation. Once put in, there are even further exams undergone, typically by third-party organisations in order for the complete fireplace suppression system to finally be handed over to the consumer.
Water mist know-how assures security, high quality and assurance through the stringent testing that’s required.
With the latest publication of water mist standards, significantly in Britain over current years, constructing builders can now be assured that the quality required for water mist methods is now at an equivalent normal to other suppression methods.
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