Introducing water mist expertise – Part 2

Water mist expertise remains to be a comparatively new concept by way of fire suppression, but it’s proving to be an thrilling improvement within the industry. As the industry evolves, so do the laws, laws and requirements in order to improve safety and enable growth. These can vary largely from nation to nation, and even region to region.
The method during which a water mist system operates is an identical mechanism to the normal 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 via 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 big ‘bar’ of metallic, to turning into the environment friendly water mist nozzles we see put in in lots of new projects/developments throughout much of the globe today.
The steel arrives for cutting

Here at Dual Mist Ltd, Stainless Steel 304 is used for many components as it is extremely sturdy and corrosion resistant compared to different similar metals. The body is machined out of Brass CZ121, which arrives as giant bars of metallic that 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 firms have the ability to machine the parts they require in-house though it might possibly show very helpful for value and manufacturing functions as we’re about to see.

The steel is fed to a Nakamura WT150 CNC lathe. This high-performance Japanese machine device is supplied with carbide tooling and high-pressure by way of coolant systems, with the twin-spindle and twin-turret making haste of the in any other case sophisticated parts. A Citizen M532 Sliding Head Lathe is used for the smaller elements.
A Citizen L12 also makes the filters with a capability of drilling 365 holes in fifty one seconds, utterly automated – this means it could turnover an unbelievable 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 supplies a corrosion-proof coating to the brass, enabling it to turn out to be far more sturdy. All components are then inspected for dimensional accuracy earlier than the assembly stage.
This Technifor Laser machine engraves every nozzle in preparation for the testing phases.

There are many small components of assorted 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 components or ‘components’. These parts are then meticulously put together and assembled by the production staff requiring a good amount of labour earlier than the final product is achieved. Various phases embody tightening with specifically adapted instruments, urgent utilizing a hand-press and utilizing a selected ‘Locktite’ method at some phases which is a threadlock that stops fixings from coming loose through the operational lifetime of the product. The ultimate stage of assembly is carefully loading the bulb and making use of the proper load to it using 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 carried out on a Technifor Laser Engraver fitted with a 4th axis unit earlier than they’re able to be placed by way of the assorted stages of testing.

Cull Testing

Also often recognized as bubble testing in layman’s terms, this test is to ensure no damage has occurred to the bulb throughout assembly and is a important take a look at for LPCB approval. The test includes using a high-powered microscope to measure the dimensions of the bubble in each bulb before placing in warm water so as to shrink the size of the bubble to nothing. Once that 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 within a small tolerance.
Leak Testing

Every nozzle is also stringently tested for leaks by making use of 24-bar strain for 1 hour and ensuring no water has escaped. It is uncommon for any leaks on the manufacturing line, however that is a particularly very important stage of the testing as leaks may happen if filth is trapped inside the seal face.
Activation Testing

On a monthly basis, random nozzles are also tested for activation by inserting the nozzle on a strain jig at numerous pressures and making use of heat to the bulbs. digital pressure gauge should all activate cleanly across the entire strain range specified to that nozzle.
A member of the manufacturing staff uses a microscope and software to determine the dimensions of each bubble in the bulb.

At Dual Mist Ltd, these exams are not simply to guarantee the quality of the production line but are additionally an important a part of the LPCB Approval. These approvals allow customers to recognise that the merchandise they’re buying are made to the highest possible quality standard in the region.
The drawback to this is that the Approval Testing system could be each costly and time-consuming – generally needing to be booked a number of months prematurely and requiring years of onerous work to realize.
The nozzles produced by Dual Mist have been put via their paces at BRE Global in terms of both hearth testing and component/type approval.
Tamper proofing

In order to ensure 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 pressure load setting on the bulb is then subsequently mounted.
The nozzles are then able to be packaged and despatched off for set up.
Here is an instance of a control panel having been put in in The Claridges Hotel, London, UK. This is where the system is operated.

Rather than having to use the heavy and labour-intensive metal pipes often utilized in high-pressure methods, low-pressure water techniques can use CPVC piping. This is a special sort of fire-resistant plastic enabling fast set up. Instead of threading each pipe, a heated glue can be used to quickly build giant pipe networks. These networks are approved to handle up to 12 bar strain. The nozzles are screwed right into a particular pipe adaptor using a half-inch fuel fitting.
An electric control panel is fitted for the system management along with pumps and a water tank, normally with a mains feed.
The system is examined, signed off and handed over to the client.
The ultimate product as quickly as put in. This exhibits how we expect to see the nozzles once a challenge has been accomplished.

As we can see there are many phases to go from metallic to nozzle head with every nozzle taking a big effort by various professionals to complete to the accredited commonplace.
Not solely do water mist nozzles require multiple stages of machining and assembling, they have to additionally bear a string of checks in order to be accredited for set up. Once put in, there are even additional checks undergone, typically by third-party organisations in order for the entire fire suppression system to lastly be handed over to the consumer.
Water mist technology assures safety, quality and assurance via the stringent testing that’s required.
With the latest publication of water mist requirements, notably in Britain over latest years, constructing developers can now be assured that the quality required for water mist techniques is now at an equivalent standard to other suppression techniques.
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