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Introducing water mist know-how – Part 2

Water mist expertise is still a relatively new idea when it comes to fireplace suppression, yet it’s proving to be an thrilling improvement in the business. As the trade evolves, so do the regulations, legal guidelines and requirements in order to enhance safety and allow growth. These can range largely from nation to nation, and even region to region.
The method during which a water mist system operates is a similar mechanism to the traditional sprinkler system in that the nozzles are normally activated via a bulb which blows at a specific temperature permitting for the activation of the mist by way of 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 becoming the efficient water mist nozzles we see installed in lots of new projects/developments throughout much of the globe at present.
The steel arrives for chopping
Here at Dual Mist Ltd, Stainless Steel 304 is used for so much of elements as it is extremely durable and corrosion resistant in comparison to different similar metals. The body is machined out of Brass CZ121, which arrives as massive bars of steel which are delivered to the warehouse in 3m lengths. This is then minimize into two smaller elements ready to insert into the machine. Not all water mist corporations have the ability to machine the elements they require in-house though it could prove very helpful for value 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 provided with carbide tooling and high-pressure through coolant techniques, with the twin-spindle and twin-turret making haste of the otherwise complicated elements. A Citizen M532 Sliding Head Lathe is used for the smaller parts.
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 unimaginable 4,000 filters in a weekend completely unmanned.
The brass heads are also de-burred on the machine, removing all sharp edges earlier than being polished and despatched for Electroless Nickel Plating. This provides a corrosion-proof coating to the brass, enabling it to turn out to be much more sturdy. All components are then inspected for dimensional accuracy before the assembly stage.
This Technifor Laser machine engraves each nozzle in preparation for the testing phases.
There are many small elements of assorted sizes and shapes that make up the nozzle – In the DM4R nozzle, (as seen on the leak-testing pic) there are a complete of thirteen elements or ‘components’. These elements are then meticulously put collectively and assembled by the production staff requiring a good amount of labour before the ultimate product is achieved. Various phases embrace tightening with specifically adapted instruments, pressing using a hand-press and using a particular ‘Locktite’ formulation at some levels which is a threadlock that stops fixings from coming unfastened through the operational lifetime of the product. The last stage of assembly is carefully loading the bulb and making use of the right load to it using a torque wrench.
The assembled nozzles are then positioned on another machine in order to be labelled and uniquely identified utilizing a serial quantity. At Dual Mist Ltd this is done on a Technifor Laser Engraver fitted with a 4th axis unit earlier than they are ready to be placed via the various stages of testing.
Cull Testing
Also known as bubble testing in layman’s terms, this check 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 using a high-powered microscope to measure the scale of the bubble in every bulb earlier than inserting in heat water to be able 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 as quickly as once more so as to ensure it has returned to the original measurement within a small tolerance.
Leak Testing
Every nozzle can additionally be stringently tested for leaks by applying 24-bar pressure for 1 hour and guaranteeing no water has escaped. เครื่องมือความดัน is uncommon for any leaks on the manufacturing line, however this is an extremely vital stage of the testing as leaks might happen if filth is trapped throughout the seal face.
Activation Testing
On a monthly foundation, random nozzles are additionally tested for activation by placing the nozzle on a pressure jig at numerous pressures and applying warmth to the bulbs. The nozzles ought to all activate cleanly throughout the entire stress range specified to that nozzle.
A member of the production group makes use of a microscope and software program to discover out the dimensions of each bubble in the bulb.
At Dual Mist Ltd, these tests are not simply to guarantee the standard of the production line however are additionally an essential a part of the LPCB Approval. These approvals enable customers to recognise that the products they’re shopping for are made to the highest attainable quality commonplace within the area.
The drawback to this is that the Approval Testing system could be both costly and time-consuming – generally needing to be booked several months upfront and requiring years of exhausting work to attain.
The nozzles produced by Dual Mist have been put via their paces at BRE Global in phrases of each fireplace testing and component/type approval.
Tamper proofing
In order to guarantee that no person 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 mounted.
The nozzles are then able to be packaged and despatched off for set up.
Here is an example of a management 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 metallic pipes often utilized in high-pressure systems, low-pressure water systems can use CPVC piping. This is a special sort of fire-resistant plastic enabling fast set up. Instead of threading every pipe, a heated glue can be utilized to quickly construct massive pipe networks. These networks are accredited to handle up to 12 bar strain. The nozzles are screwed right into a special pipe adaptor using a half-inch gasoline fitting.
An electric control panel is fitted for the system management along with pumps and a water tank, normally with a mains feed.
The system is tested, signed off and handed over to the client.
The final product as soon as put in. This shows how we expect to see the nozzles once a challenge has been accomplished.
As we can see there are many levels to go from steel to nozzle head with each nozzle taking a big effort by varied professionals to finish to the approved standard.
Not only do water mist nozzles require multiple phases of machining and assembling, they must also bear a string of exams to find a way to be permitted for installation. Once put in, there are even additional exams undergone, generally by third-party organisations to ensure that the entire fireplace suppression system to finally be handed over to the shopper.
Water mist know-how assures security, quality and assurance via the stringent testing that is required.
With the latest publication of water mist standards, particularly in Britain over recent years, constructing developers can now be assured that the standard required for water mist methods is now at an equal normal to different suppression methods.
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