Introducing water mist technology – Part 2

Water mist expertise remains to be a comparatively new idea in phrases of fireplace suppression, but it’s proving to be an thrilling improvement in the business. As the industry evolves, so do the rules, laws and requirements in order to improve safety and enable development. These can differ largely from nation to country, and even area to area.
The way in which a water mist system operates is an identical mechanism to the normal sprinkler system in that the nozzles are usually activated via 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 installed – from arriving as a big ‘bar’ of steel, to changing into the efficient water mist nozzles we see installed in plenty of new projects/developments across much of the globe today.
The steel arrives for cutting
Here at Dual Mist Ltd, Stainless Steel 304 is used for many components as it is extremely sturdy and corrosion resistant compared to other related metals. เกจวัดแรงดันลมดิจิตอล is machined out of Brass CZ121, which arrives as giant bars of metallic which may be delivered to the warehouse in 3m lengths. This is then cut into two smaller components ready to insert into the machine. Not all water mist corporations have the power to machine the components they require in-house although it may possibly show very beneficial for cost and production purposes as we are about to see.
The steel is fed to a Nakamura WT150 CNC lathe. This high-performance Japanese machine tool is equipped with carbide tooling and high-pressure by way of coolant systems, with the twin-spindle and twin-turret making haste of the otherwise sophisticated parts. 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 fifty one seconds, completely automated – this implies it can turnover an unimaginable four,000 filters in a weekend fully unmanned.
The brass heads are additionally de-burred on the machine, eradicating all sharp edges before being polished and despatched for Electroless Nickel Plating. This offers a corrosion-proof coating to the brass, enabling it to become much more sturdy. All elements are then inspected for dimensional accuracy before the meeting stage.
This Technifor Laser machine engraves each nozzle in preparation for the testing levels.
There are many small elements of assorted styles and sizes that make up the nozzle – In the DM4R nozzle, (as seen on the leak-testing pic) there are a total of 13 elements or ‘components’. These components are then meticulously put together and assembled by the production staff requiring a good amount of labour before the ultimate product is achieved. Various phases include tightening with specially tailored tools, urgent utilizing a hand-press and using a particular ‘Locktite’ formula at some levels which is a threadlock that forestalls fixings from coming free during the operational lifetime of the product. The last stage of assembly is fastidiously loading the bulb and applying the correct load to it utilizing a torque wrench.
The assembled nozzles are then placed on another machine in order to be labelled and uniquely identified using a serial number. At Dual Mist Ltd that is done on a Technifor Laser Engraver fitted with a 4th axis unit before they’re able to be positioned by way of the assorted levels of testing.
เพรสเชอร์เกจลม known as bubble testing in layman’s terms, this check is to ensure no harm has occurred to the bulb throughout assembly and is a critical take a look at for LPCB approval. The test entails utilizing a high-powered microscope to measure the size of the bubble in every bulb before placing in heat water so as to shrink the scale of the bubble to nothing. Once that is checked, the nozzles are then left to rest and return to room temperature earlier than the bubble is measured once once more to have the ability to ensure it has returned to the original measurement within a small tolerance.
Leak Testing
Every nozzle can additionally be stringently examined for leaks by applying 24-bar pressure for 1 hour and making certain no water has escaped. It is uncommon for any leaks on the manufacturing line, however that is an especially important stage of the testing as leaks might occur if dust is trapped inside the seal face.
Activation Testing
On a month-to-month foundation, random nozzles are additionally tested for activation by placing the nozzle on a stress jig at varied pressures and making use of heat to the bulbs. The nozzles ought to all activate cleanly across the complete stress range specified to that nozzle.
A member of the manufacturing staff makes use of a microscope and software to find out the dimensions of each bubble in the bulb.
At Dual Mist Ltd, these tests usually are not just to guarantee the standard of the production line but are also an necessary part of the LPCB Approval. These approvals enable customers to recognise that the merchandise they’re buying are made to the very best attainable high quality normal in the region.
The drawback to that is that the Approval Testing system may be each pricey and time-consuming – generally needing to be booked a number of months prematurely and requiring years of hard work to achieve.
The nozzles produced by Dual Mist have been put via their paces at BRE Global when it comes to both fire testing and component/type approval.
Tamper proofing
In order to make certain that no person is tempted to interfere with the grub screw holding the bulb, a small plastic bung is pressed into the grub screw. The stress 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 put in in The Claridges Hotel, London, UK. This is the place the system is operated.
Rather than having to make use of 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 kind of fire-resistant plastic enabling fast installation. Instead of threading each pipe, a heated glue can be used to shortly construct massive pipe networks. These networks are approved to handle up to 12 bar pressure. The nozzles are screwed right into a particular pipe adaptor using a half-inch gas fitting.
An electrical control panel is fitted for the system control along with pumps and a water tank, usually with a mains feed.
The system is tested, signed off and handed over to the client.
The final product once put in. This reveals how we anticipate to see the nozzles once a venture has been completed.
As we can see there are numerous stages to go from steel to nozzle head with each nozzle taking a major effort by numerous professionals to complete to the permitted standard.
Not solely do water mist nozzles require multiple levels of machining and assembling, they have to also bear a string of exams so as to be approved for installation. Once installed, there are even additional tests undergone, typically by third-party organisations in order for the entire fire suppression system to finally be handed over to the shopper.
Water mist expertise assures security, quality and assurance by way of the stringent testing that’s required.
With the latest publication of water mist standards, notably in Britain over recent years, building developers can now be assured that the standard required for water mist systems is now at an equivalent normal to other suppression methods.
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