Introducing water mist expertise – Part 2

Water mist technology remains to be a relatively new concept when it comes to fire suppression, but it’s proving to be an thrilling growth within the trade. As the industry evolves, so do the laws, legal guidelines and necessities so as to enhance security and enable improvement. These can range largely from nation to nation, and even area to region.
The way by which a water mist system operates is an analogous mechanism to the standard sprinkler system in that the nozzles are often activated through a bulb which blows at a selected temperature allowing 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 metal, to changing into the environment friendly water mist nozzles we see put in in many new projects/developments throughout much of the globe right now.
The metallic arrives for chopping
Here at Dual Mist Ltd, Stainless Steel 304 is used for many parts as this may be very durable and corrosion resistant compared to other similar metals. The physique is machined out of Brass CZ121, which arrives as massive bars of metallic that are delivered to the warehouse in 3m lengths. This is then cut into two smaller parts ready to insert into the machine. Not all water mist firms have the power to machine the elements they require in-house though it can show very helpful for price and manufacturing purposes as we’re about to see.
Machining
The metal is fed to a Nakamura WT150 CNC lathe. This high-performance Japanese machine tool is supplied with carbide tooling and high-pressure via coolant systems, 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 parts.
A Citizen L12 additionally makes the filters with a capability of drilling 365 holes in fifty one seconds, utterly automated – this implies it can turnover an unimaginable 4,000 filters in a weekend utterly unmanned.
The brass heads are also de-burred on the machine, removing all sharp edges before being polished and sent for Electroless Nickel Plating. This supplies a corrosion-proof coating to the brass, enabling it to become far more durable. All components are then inspected for dimensional accuracy before the assembly stage.
This Technifor Laser machine engraves every nozzle in preparation for the testing stages.
Assembly
There are many small parts 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 elements or ‘components’. These elements are then meticulously put collectively and assembled by the manufacturing team requiring a fair amount of labour before the ultimate product is achieved. Various stages embody tightening with specially tailored tools, urgent utilizing a hand-press and using a particular ‘Locktite’ formula at some phases which is a threadlock that forestalls fixings from coming unfastened in the course of the operational lifetime of the product. The final stage of meeting is fastidiously loading the bulb and applying the correct load to it using a torque wrench.
The assembled nozzles are then positioned on one other machine in order to be labelled and uniquely identified using a serial quantity. At Dual Mist Ltd that is carried out on a Technifor Laser Engraver fitted with a 4th axis unit earlier than they’re able to be placed through the various levels of testing.
Testing
Cull Testing
Also generally recognized as bubble testing in layman’s terms, this check is to make sure no injury has occurred to the bulb during assembly and is a critical check for LPCB approval. The check involves using a high-powered microscope to measure the dimensions of the bubble in each bulb earlier than inserting in heat water to be able to shrink the size of the bubble to nothing. Once that is checked, the nozzles are then left to relaxation and return to room temperature before the bubble is measured as soon as again so as to ensure it has returned to the unique dimension within a small tolerance.
Leak Testing
Every nozzle can be stringently tested for leaks by applying 24-bar strain for 1 hour and making certain 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 might happen if dust is trapped throughout the seal face.
Activation Testing
On a monthly foundation, random nozzles are additionally examined for activation by placing the nozzle on a strain jig at numerous pressures and making use of heat to the bulbs. The nozzles ought to all activate cleanly throughout the entire pressure range specified to that nozzle.
A member of the production group makes use of a microscope and software program to discover out the scale of each bubble in the bulb.
Approvals
At Dual Mist Ltd, these checks aren’t simply to guarantee the quality of the production line however are also an necessary part of the LPCB Approval. These approvals allow clients to recognise that the merchandise they’re buying are made to the best attainable high quality standard within the area.
The disadvantage to this is that the Approval Testing system can be each expensive and time-consuming – typically needing to be booked several months upfront and requiring years of hard work to attain.
The nozzles produced by Dual Mist have been put by way of their paces at BRE Global in phrases of each fire testing and component/type approval.
Tamper proofing
In order to ensure that no person is tempted to intrude 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 fastened.
The nozzles are then able 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 the place the system is operated.
เกจวัดแรงดันเครื่องกรองน้ำ than having to make use of the heavy and labour-intensive steel pipes typically used in high-pressure systems, low-pressure water techniques can use CPVC piping. This is a special kind of fire-resistant plastic enabling quick set up. Instead of threading each pipe, a heated glue can be utilized to rapidly construct massive pipe networks. These networks are accredited to handle as much as 12 bar strain. The nozzles are screwed into a particular 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, normally 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 expect to see the nozzles as quickly as a project has been accomplished.
Conclusion
As we will see there are many phases to go from metal to nozzle head with each nozzle taking a big effort by numerous professionals to complete to the accredited standard.
Not solely do water mist nozzles require a quantity of stages of machining and assembling, they have to additionally undergo a string of exams to find a way to be accredited for installation. Once put in, there are even further checks undergone, sometimes by third-party organisations in order for the entire hearth suppression system to finally be handed over to the client.
Water mist know-how assures security, quality and assurance through the stringent testing that is required.
With the recent publication of water mist requirements, particularly in Britain over recent years, building developers can now be assured that the standard required for water mist techniques is now at an equivalent standard to different suppression methods.
For extra info, go to www.dualmist.com
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