Water mist expertise continues to be a comparatively new concept when it comes to fire suppression, but it is proving to be an exciting development within the industry. As the industry evolves, so do the rules, legal guidelines and requirements so as to enhance safety and allow improvement. These can vary largely from nation to country, and even area to area.
The way 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 particular temperature allowing 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 large ‘bar’ of metal, to turning into the environment friendly water mist nozzles we see put in in many new projects/developments across a lot of the globe at present.
The metallic arrives for cutting

Here at Dual Mist Ltd, Stainless Steel 304 is used for a lot of parts as this could be very durable and corrosion resistant compared to other similar metals. The body is machined out of Brass CZ121, which arrives as massive bars of metal which might 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 firms have the flexibility to machine the elements they require in-house though it could prove very helpful for cost and production purposes as we’re about to see.
ไดอะแฟรม ซีล is fed to a Nakamura WT150 CNC lathe. This high-performance Japanese machine tool is provided 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 also makes the filters with a capability of drilling 365 holes in 51 seconds, completely automated – this means it could turnover an unbelievable four,000 filters in a weekend utterly 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 supplies a corrosion-proof coating to the brass, enabling it to turn into far more sturdy. All parts are then inspected for dimensional accuracy before the meeting stage.
This Technifor Laser machine engraves each nozzle in preparation for the testing phases.

There are many small elements of various 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 together and assembled by the manufacturing staff requiring a fair amount of labour before the ultimate product is achieved. Various levels embody tightening with specifically adapted tools, pressing using a hand-press and using a particular ‘Locktite’ formula at some phases which is a threadlock that stops fixings from coming unfastened during the operational lifetime of the product. The last stage of meeting is rigorously loading the bulb and applying the right 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 utilizing a serial number. At Dual Mist Ltd this is done on a Technifor Laser Engraver fitted with a 4th axis unit before they are able to be positioned through the assorted stages of testing.

Cull Testing

Also often identified as bubble testing in layman’s terms, this check is to ensure no harm has occurred to the bulb throughout meeting and is a critical check for LPCB approval. The test involves using a high-powered microscope to measure the dimensions of the bubble in every bulb earlier than placing 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 as quickly as once more to find a way to ensure it has returned to the unique size inside a small tolerance.
Leak Testing

Every nozzle can be stringently tested for leaks by making use of 24-bar strain for 1 hour and guaranteeing no water has escaped. It is uncommon for any leaks on the manufacturing line, however that is a particularly important stage of the testing as leaks could occur if dust is trapped within the seal face.
Activation Testing

On a monthly basis, random nozzles are also examined for activation by putting the nozzle on a pressure jig at various pressures and making use of warmth to the bulbs. The nozzles should all activate cleanly throughout the complete strain range specified to that nozzle.
A member of the production group makes use of a microscope and software to determine the dimensions of every bubble in the bulb.

At Dual Mist Ltd, these exams aren’t just to assure the standard of the production line but are also an important part of the LPCB Approval. These approvals enable prospects to recognise that the products they are shopping for are made to the very best potential high quality normal within the region.
The disadvantage to that is that the Approval Testing system can be each costly and time-consuming – sometimes needing to be booked several months upfront and requiring years of hard work to achieve.
The nozzles produced by Dual Mist have been put by way of their paces at BRE Global by way of both hearth testing and component/type approval.
Tamper proofing

In order to ensure 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 strain load setting on the bulb is then subsequently fastened.
The nozzles are then able to be packaged and sent off for installation.
Here is an instance of a control panel having been put in 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 usually utilized in high-pressure methods, low-pressure water techniques can use CPVC piping. This is a particular type of fire-resistant plastic enabling quick set up. Instead of threading every pipe, a heated glue can be used to quickly build large pipe networks. These networks are accredited to deal with up to 12 bar stress. The nozzles are screwed into a particular pipe adaptor using a half-inch gasoline becoming.
An electrical control panel is fitted for the system control together 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 once put in. This shows how we count on to see the nozzles as soon as a challenge has been completed.

As we are ready to see there are many levels to go from steel to nozzle head with each nozzle taking a big effort by varied professionals to complete to the permitted standard.
Not only do water mist nozzles require multiple levels of machining and assembling, they must additionally endure a string of tests in order to be permitted for set up. Once put in, there are even further checks undergone, generally by third-party organisations in order for the whole fire suppression system to lastly be handed over to the consumer.
Water mist know-how assures safety, high quality and assurance via the stringent testing that’s required.
With the recent publication of water mist requirements, significantly in Britain over recent years, constructing developers can now be assured that the standard required for water mist methods is now at an equal standard to different suppression methods.
For more information, go to www.dualmist.com

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