Introducing water mist technology – Part 2

Water mist know-how is still a relatively new concept by method of fire suppression, yet it’s proving to be an thrilling growth in the industry. As the business evolves, so do the laws, legal guidelines and requirements to have the ability to enhance safety and enable growth. These can vary largely from country to country, and even region to region.
The way during which a water mist system operates is an identical mechanism to the traditional sprinkler system in that the nozzles are normally activated by way of a bulb which blows at a particular 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 large ‘bar’ of metallic, to becoming the environment friendly water mist nozzles we see installed in lots of new projects/developments across a lot of the globe today.
The metallic arrives for cutting
Here at Dual Mist Ltd, Stainless Steel 304 is used for many parts as it is extremely durable and corrosion resistant compared to other similar metals. The body is machined out of Brass CZ121, which arrives as massive bars of metal that are delivered to the warehouse in 3m lengths. This is then reduce into two smaller parts able to insert into the machine. Not all water mist companies have the power to machine the elements they require in-house although it may possibly show very helpful for value and manufacturing functions as we are about to see.
The metal is fed to a Nakamura WT150 CNC lathe. This high-performance Japanese machine device is equipped with carbide tooling and high-pressure via coolant methods, with the twin-spindle and twin-turret making haste of the otherwise difficult components. A Citizen M532 Sliding Head Lathe is used for the smaller components.
A Citizen L12 additionally makes the filters with a capability of drilling 365 holes in fifty one seconds, fully automated – this implies it can turnover an unimaginable four,000 filters in a weekend completely unmanned.
เครื่องมือที่ใช้ในการวัดความดัน are additionally de-burred on the machine, eradicating 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 become far 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 parts of varied shapes and sizes that make up the nozzle – In the DM4R nozzle, (as seen on the leak-testing pic) there are a complete of 13 elements or ‘components’. These components are then meticulously put collectively and assembled by the manufacturing team requiring a good amount of labour before the ultimate product is achieved. Various levels embrace tightening with specifically tailored tools, urgent utilizing a hand-press and using a particular ‘Locktite’ method at some stages which is a threadlock that stops fixings from coming loose through the operational lifetime of the product. The ultimate stage of assembly is rigorously loading the bulb and applying the correct load to it utilizing a torque wrench.
The assembled nozzles are then positioned on one other machine so as to be labelled and uniquely identified utilizing a serial number. At Dual Mist Ltd that is accomplished on a Technifor Laser Engraver fitted with a 4th axis unit earlier than they are able to be positioned via the varied levels of testing.
Cull Testing
Also generally known as bubble testing in layman’s terms, this take a look at is to make sure no harm has occurred to the bulb during meeting and is a important 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 before putting in heat water in order 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 earlier than the bubble is measured once again in order to guarantee it has returned to the unique 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 ensuring no water has escaped. It is rare for any leaks on the production line, but this is an especially important stage of the testing as leaks might happen if filth is trapped throughout the seal face.
Activation Testing
On a month-to-month basis, random nozzles are also tested for activation by putting the nozzle on a strain jig at varied 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 team uses a microscope and software program to find out the scale of each bubble within the bulb.
At Dual Mist Ltd, these checks are not just to guarantee the standard of the production line but are also an important a part of the LPCB Approval. These approvals allow customers to recognise that the products they are shopping for are made to the highest potential quality standard in the region.
The drawback to this is that the Approval Testing system can be each pricey and time-consuming – typically needing to be booked several months prematurely and requiring years of onerous work to achieve.
The nozzles produced by Dual Mist have been put through their paces at BRE Global in phrases of each fireplace testing and component/type approval.
Tamper proofing
In order to make sure that nobody is tempted to intervene 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 able 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 where the system is operated.
Rather than having to use the heavy and labour-intensive metallic pipes typically utilized in high-pressure systems, low-pressure water methods can use CPVC piping. This is a special type of fire-resistant plastic enabling quick installation. Instead of threading every pipe, a heated glue can be used to shortly construct giant pipe networks. These networks are permitted to deal with as much as 12 bar stress. The nozzles are screwed right into a special pipe adaptor using a half-inch fuel fitting.
An electrical control panel is fitted for the system management along with pumps and a water tank, usually with a mains feed.
The system is examined, signed off and handed over to the shopper.
The ultimate product once installed. This shows how we count on to see the nozzles as quickly as a project has been completed.
As we can see there are many levels to go from metallic to nozzle head with each nozzle taking a major effort by numerous professionals to finish to the approved commonplace.
Not only do water mist nozzles require multiple stages of machining and assembling, they have to additionally endure a string of tests to be able to be accredited for set up. Once put in, there are even further tests undergone, sometimes by third-party organisations in order for the complete hearth suppression system to finally be handed over to the shopper.
Water mist expertise assures safety, quality and assurance via the stringent testing that is required.
With the current publication of water mist standards, notably in Britain over recent years, building builders can now be assured that the standard required for water mist systems is now at an equivalent commonplace to different suppression methods.
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