Water mist know-how continues to be a comparatively new idea in phrases of fire suppression, but it’s proving to be an exciting growth in the industry. As the trade evolves, so do the regulations, legal guidelines and requirements to be able to improve security and allow development. These can differ largely from country to nation, and even region to area.
The method in which a water mist system operates is a similar mechanism to the standard sprinkler system in that the nozzles are often activated through a bulb which blows at a selected temperature permitting for the activation of the mist through 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 steel, to changing into the efficient water mist nozzles we see put in in many new projects/developments throughout a lot of the globe at present.
The metallic arrives for slicing
Here at Dual Mist Ltd, Stainless Steel 304 is used for so much of parts as this could be very durable and corrosion resistant in comparability to different comparable metals. The body is machined out of Brass CZ121, which arrives as massive bars of metallic which are delivered to the warehouse in 3m lengths. This is then minimize into two smaller elements able to insert into the machine. Not all water mist companies have the ability to machine the elements they require in-house although it could show very beneficial for price and production functions as we’re about to see.
The steel is fed to a Nakamura WT150 CNC lathe. This high-performance Japanese machine software is supplied with carbide tooling and high-pressure by way of coolant techniques, 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 fifty one seconds, fully automated – this means it can turnover an unimaginable 4,000 filters in a weekend fully unmanned.
The brass heads are also de-burred on the machine, eradicating all sharp edges before being polished and sent for Electroless Nickel Plating. This provides a corrosion-proof coating to the brass, enabling it to become far more sturdy. All elements are then inspected for dimensional accuracy before the meeting stage.
This Technifor Laser machine engraves every 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 components or ‘components’. These elements are then meticulously put collectively and assembled by the production group requiring a good quantity of labour before the final product is achieved. Various levels embrace tightening with specifically tailored instruments, pressing utilizing a hand-press and utilizing a specific ‘Locktite’ formula at some levels which is a threadlock that prevents fixings from coming unfastened in the course of the operational lifetime of the product. The last stage of meeting is rigorously loading the bulb and applying the proper 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 quantity. At Dual Mist Ltd that is carried out on a Technifor Laser Engraver fitted with a 4th axis unit before they are able to be positioned via the various levels of testing.
Cull Testing
Also known as bubble testing in layman’s phrases, this take a look at is to make sure no injury has occurred to the bulb during assembly and is a important test for LPCB approval. The check involves utilizing a high-powered microscope to measure the dimensions of the bubble in each bulb earlier than placing in heat water to have the ability to shrink the dimensions 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 as soon as once more so as to ensure it has returned to the unique size within a small tolerance.
Leak Testing
Every nozzle can additionally be stringently tested for leaks by applying 24-bar stress for 1 hour and making certain no water has escaped. It is rare for any leaks on the production line, however this is a particularly vital stage of the testing as leaks might happen if dust is trapped within the seal face.
Activation Testing
On a monthly foundation, random nozzles are additionally tested for activation by inserting the nozzle on a strain jig at various pressures and making use of heat to the bulbs. The nozzles ought to all activate cleanly throughout the complete pressure range specified to that nozzle.
A member of the manufacturing group makes use of a microscope and software to determine the dimensions of every bubble in the bulb.
At Dual Mist Ltd, these tests are not simply to assure the quality of the production line but are also an necessary a half of the LPCB Approval. These approvals enable clients to recognise that the merchandise they are buying are made to the best attainable quality normal within the area.
The disadvantage to that is that the Approval Testing system could be both pricey and time-consuming – typically needing to be booked a number of months in advance and requiring years of hard work to attain.
The nozzles produced by Dual Mist have been put through their paces at BRE Global in phrases of each fire testing and component/type approval.
Tamper proofing
In order to make certain that nobody 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 mounted.
The nozzles are then ready 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 make use of the heavy and labour-intensive steel pipes typically used in high-pressure methods, low-pressure water techniques can use CPVC piping. This is a special kind of fire-resistant plastic enabling fast installation. Instead of threading each pipe, a heated glue can be used to rapidly construct large pipe networks. These networks are accredited to deal with as a lot as 12 bar stress. The nozzles are screwed right into a particular pipe adaptor using a half-inch gas becoming.
An electric management panel is fitted for the system management along with pumps and a water tank, often with a mains feed.
The system is tested, signed off and handed over to the client.
The ultimate product once installed. This reveals how we anticipate to see the nozzles once a project has been completed.
As we are in a position to see there are tons of stages to go from metal to nozzle head with every nozzle taking a significant effort by numerous professionals to finish to the permitted normal.
Not only do water mist nozzles require multiple stages of machining and assembling, they need to additionally bear a string of exams in order to be accredited for installation. Once put in, there are even further tests undergone, typically by third-party organisations in order for the entire hearth suppression system to lastly be handed over to the shopper.
Water mist expertise assures safety, high quality and assurance via the stringent testing that’s required.
With the recent publication of water mist requirements, particularly in Britain over current years, constructing builders can now be assured that the quality required for water mist techniques is now at an equal normal to other suppression systems.
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