Introducing water mist expertise – Part 2

Water mist expertise remains to be a relatively new concept by way of fire suppression, but it is proving to be an exciting growth within the business. As the business evolves, so do the rules, legal guidelines and necessities to be able to improve security and enable growth. These can range largely from country to country, and even area to area.
The way in which a water mist system operates is an identical mechanism to the standard sprinkler system in that the nozzles are often activated through 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 installed – from arriving as a large ‘bar’ of steel, to becoming the environment friendly water mist nozzles we see installed in many new projects/developments throughout a lot of the globe today.
The metal arrives for slicing

Here at Dual Mist Ltd, Stainless Steel 304 is used for a lot of elements as this could be very sturdy and corrosion resistant compared to different related metals. The body is machined out of Brass CZ121, which arrives as massive bars of metallic which might be delivered to the warehouse in 3m lengths. This is then reduce into two smaller components ready to insert into the machine. Not all water mist corporations have the ability to machine the components they require in-house though it may possibly prove very helpful for cost and manufacturing purposes as we’re about to see.

The metal is fed to a Nakamura WT150 CNC lathe. This high-performance Japanese machine tool is equipped with carbide tooling and high-pressure via coolant systems, with the twin-spindle and twin-turret making haste of the in any other case sophisticated elements. A Citizen M532 Sliding Head Lathe is used for the smaller parts.
A Citizen L12 also makes the filters with a capability of drilling 365 holes in 51 seconds, utterly automated – this means it may possibly turnover an unimaginable 4,000 filters in a weekend utterly unmanned.
The brass heads are additionally de-burred on the machine, removing all sharp edges earlier than being polished and sent for Electroless Nickel Plating. This provides a corrosion-proof coating to the brass, enabling it to become much more sturdy. All elements are then inspected for dimensional accuracy before the assembly stage.
This Technifor Laser machine engraves every nozzle in preparation for the testing stages.

There are many small components 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 13 parts or ‘components’. These components are then meticulously put collectively and assembled by the manufacturing staff requiring a good amount of labour before the final product is achieved. Various levels embrace tightening with specifically adapted instruments, urgent utilizing a hand-press and using a specific ‘Locktite’ formulation at some levels which is a threadlock that stops fixings from coming loose during the operational lifetime of the product. The ultimate stage of meeting is fastidiously loading the bulb and making use of the right load to it utilizing a torque wrench.
The assembled nozzles are then placed on another machine so as to be labelled and uniquely recognized using a serial quantity. At Dual Mist Ltd that is accomplished on a Technifor Laser Engraver fitted with a 4th axis unit before they’re able to be placed via the various levels of testing.

Cull Testing

Also often known as bubble testing in layman’s phrases, this take a look at is to ensure no injury has occurred to the bulb during assembly and is a important take a look at for LPCB approval. diaphragm seal take a look at involves using a high-powered microscope to measure the scale of the bubble in every bulb earlier than placing in warm water in order 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 before the bubble is measured once again so as to ensure it has returned to the unique measurement inside a small tolerance.
Leak Testing

Every nozzle can also be stringently examined for leaks by making use of 24-bar stress for 1 hour and guaranteeing no water has escaped. It is uncommon for any leaks on the production line, however this is an especially very important stage of the testing as leaks might occur 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 varied pressures and making use of warmth to the bulbs. The nozzles should all activate cleanly across the complete strain vary specified to that nozzle.
A member of the production staff uses a microscope and software program to find out the size of every bubble within the bulb.

At Dual Mist Ltd, these tests are not simply to assure the standard of the manufacturing line but are also an essential a part of the LPCB Approval. These approvals enable customers to recognise that the merchandise they are shopping for are made to the highest attainable high quality commonplace in the region.
The drawback to this is that the Approval Testing system may be each expensive and time-consuming – typically needing to be booked a quantity of months upfront and requiring years of onerous work to achieve.
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 make sure that no one is tempted to intervene 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 mounted.
The nozzles are then ready to be packaged and sent off for installation.
Here is an example of a management panel having been installed in The Claridges Hotel, London, UK. This is the place the system is operated.

Rather than having to use the heavy and labour-intensive metal pipes typically utilized in high-pressure methods, low-pressure water techniques can use CPVC piping. This is a particular sort of fire-resistant plastic enabling quick installation. Instead of threading every pipe, a heated glue can be used to shortly build 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 utilizing a half-inch gasoline becoming.
An electrical management panel is fitted for the system management 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 final product as soon as put in. This exhibits how we count on to see the nozzles once a challenge has been completed.

As we will see there are numerous phases to go from metal to nozzle head with every nozzle taking a significant effort by numerous professionals to finish to the approved commonplace.
Not only do water mist nozzles require a number of levels of machining and assembling, they have to additionally bear a string of tests in order to be approved for installation. Once put in, there are even further exams undergone, sometimes by third-party organisations to ensure that the whole fire suppression system to finally be handed over to the shopper.
Water mist know-how assures safety, high quality and assurance through the stringent testing that is required.
With the current publication of water mist standards, significantly in Britain over current years, constructing builders can now be assured that the quality required for water mist systems is now at an equivalent commonplace to different suppression techniques.
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