Introducing water mist technology – Part 2

Water mist know-how remains to be a comparatively new idea when it comes to hearth suppression, yet it’s proving to be an exciting growth in the trade. As the business evolves, so do the regulations, legal guidelines and requirements in order to improve security and enable development. These can differ largely from nation to nation, and even region to region.
The way in which a water mist system operates is an analogous mechanism to the traditional sprinkler system in that the nozzles are normally activated via a bulb which blows at a specific temperature permitting for the activation of the mist through 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 big ‘bar’ of metallic, to turning into the environment friendly water mist nozzles we see put in in lots of new projects/developments across much of the globe today.
The metallic arrives for chopping

Here at Dual Mist Ltd, Stainless Steel 304 is used for a lot of parts as this may be very durable and corrosion resistant in comparability to different similar metals. The body is machined out of Brass CZ121, which arrives as massive bars of steel which might be delivered to the warehouse in 3m lengths. This is then reduce into two smaller components ready to insert into the machine. เพรสเชอร์เกจคือ have the ability to machine the elements they require in-house though it could prove very helpful for cost and production functions as we are 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 through coolant techniques, with the twin-spindle and twin-turret making haste of the otherwise complicated elements. A Citizen M532 Sliding Head Lathe is used for the smaller elements.
A Citizen L12 additionally makes the filters with a capability of drilling 365 holes in fifty one seconds, utterly automated – this implies it may possibly turnover an incredible 4,000 filters in a weekend completely unmanned.
The brass heads are also de-burred on the machine, eradicating all sharp edges earlier than being polished and sent for Electroless Nickel Plating. This offers a corrosion-proof coating to the brass, enabling it to become rather more sturdy. All parts are then inspected for dimensional accuracy before the meeting stage.
This Technifor Laser machine engraves every nozzle in preparation for the testing phases.

There are many small components of assorted sizes and shapes that make up the nozzle – In the DM4R nozzle, (as seen on the leak-testing pic) there are a total of 13 parts or ‘components’. These elements are then meticulously put together and assembled by the manufacturing staff requiring a good quantity of labour earlier than the ultimate product is achieved. Various levels embrace tightening with specifically adapted tools, urgent utilizing a hand-press and utilizing a particular ‘Locktite’ formula at some phases which is a threadlock that stops fixings from coming free in the course of the operational lifetime of the product. The last stage of meeting is rigorously loading the bulb and applying the correct load to it using a torque wrench.
The assembled nozzles are then placed on another machine so as to be labelled and uniquely identified using a serial quantity. At Dual Mist Ltd that is done on a Technifor Laser Engraver fitted with a 4th axis unit before they are able to be positioned by way of the assorted levels of testing.

Cull Testing

Also generally recognized as bubble testing in layman’s phrases, this check is to ensure no injury has occurred to the bulb during meeting and is a crucial test for LPCB approval. The test entails utilizing a high-powered microscope to measure the scale of the bubble in each bulb before putting in warm water to be able to shrink the scale of the bubble to nothing. Once this is checked, the nozzles are then left to rest and return to room temperature before the bubble is measured once once more in order to guarantee it has returned to the original size inside a small tolerance.
Leak Testing

Every nozzle can additionally be stringently tested for leaks by making use of 24-bar stress for 1 hour and ensuring no water has escaped. It is uncommon for any leaks on the production line, however this is a particularly vital stage of the testing as leaks may happen if dirt is trapped within the seal face.
Activation Testing

On a monthly basis, random nozzles are additionally tested for activation by putting the nozzle on a pressure jig at numerous pressures and applying heat to the bulbs. The nozzles should all activate cleanly throughout the complete strain range specified to that nozzle.
A member of the manufacturing team makes use of a microscope and software to determine the dimensions of each bubble in the bulb.

At Dual Mist Ltd, these exams aren’t simply to assure the quality of the manufacturing line however are also an necessary part of the LPCB Approval. These approvals enable customers to recognise that the merchandise they’re buying are made to the very best potential high quality standard within the region.
The disadvantage to that is that the Approval Testing system could be both costly and time-consuming – typically needing to be booked several months prematurely and requiring years of onerous work to realize.
The nozzles produced by Dual Mist have been put through their paces at BRE Global by method of each fire testing and component/type approval.
Tamper proofing

In order to ensure that no one is tempted to interfere 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 fixed.
The nozzles are then ready to be packaged and despatched 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 usually utilized in high-pressure systems, low-pressure water systems can use CPVC piping. This is a particular type of fire-resistant plastic enabling fast set up. Instead of threading every pipe, a heated glue can be used to rapidly construct large pipe networks. These networks are accredited to handle up to 12 bar pressure. The nozzles are screwed right into a particular pipe adaptor using a half-inch fuel becoming.
An electrical control panel is fitted for the system control 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 last product once put in. This shows how we anticipate to see the nozzles as quickly as a venture has been completed.

As we can see there are lots of phases to go from steel to nozzle head with every nozzle taking a big effort by varied professionals to finish to the permitted standard.
Not only do water mist nozzles require multiple phases of machining and assembling, they have to additionally endure a string of checks so as to be accredited for installation. Once installed, there are even further exams undergone, typically by third-party organisations to guarantee that the entire hearth suppression system to finally be handed over to the shopper.
Water mist technology assures safety, quality and assurance via the stringent testing that is required.
With the recent publication of water mist standards, particularly in Britain over current years, building developers can now be assured that the quality required for water mist methods is now at an equivalent commonplace to other suppression methods.
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