Introducing water mist technology – Part 2

Water mist technology is still a comparatively new concept when it comes to fireplace suppression, but it’s proving to be an thrilling improvement within the trade. As the business evolves, so do the laws, legal guidelines and requirements so as to enhance security and enable development. These can differ largely from nation to nation, and even area to area.
The means by which a water mist system operates is an identical mechanism to the standard sprinkler system in that the nozzles are often activated by way of a bulb which blows at a specific 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 big ‘bar’ of metal, to turning into the environment friendly water mist nozzles we see put in in many new projects/developments throughout much of the globe at present.
The metallic arrives for chopping
Here at Dual Mist Ltd, Stainless Steel 304 is used for so much of elements as it is extremely durable and corrosion resistant in comparability to other related metals. The body 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 elements able to insert into the machine. Not all water mist companies have the flexibility to machine the elements they require in-house though it can prove very beneficial 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 equipped with carbide tooling and high-pressure via coolant techniques, with the twin-spindle and twin-turret making haste of the otherwise sophisticated parts. A Citizen M532 Sliding Head Lathe is used for the smaller elements.
A Citizen L12 also makes the filters with a functionality of drilling 365 holes in 51 seconds, fully automated – this means it could turnover an unbelievable 4,000 filters in a weekend completely unmanned.
The brass heads are additionally de-burred on the machine, eradicating all sharp edges before being polished and sent for Electroless Nickel Plating. This offers a corrosion-proof coating to the brass, enabling it to become rather more durable. All parts are then inspected for dimensional accuracy earlier than the assembly stage.
This Technifor Laser machine engraves each nozzle in preparation for the testing levels.
Assembly
There are many small components of various shapes and sizes that make up the nozzle – In the DM4R nozzle, (as seen on the leak-testing pic) there are a total of thirteen elements or ‘components’. These components are then meticulously put collectively and assembled by the manufacturing staff requiring a good quantity of labour before the ultimate product is achieved. Various levels include tightening with specifically adapted tools, pressing using a hand-press and using a specific ‘Locktite’ formula at some stages which is a threadlock that prevents fixings from coming free in the course of the operational lifetime of the product. The ultimate stage of meeting 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 another machine so as to be labelled and uniquely recognized utilizing a serial number. At Dual Mist Ltd this is accomplished on a Technifor Laser Engraver fitted with a 4th axis unit before they’re able to be positioned through the varied levels of testing.
Testing
Cull Testing
Also known as bubble testing in layman’s phrases, this test is to ensure no damage has occurred to the bulb throughout meeting and is a important test for LPCB approval. เกจวัดแรงดันน้ำราคา entails utilizing a high-powered microscope to measure the dimensions of the bubble in every bulb earlier than placing in heat water in order to shrink the dimensions of the bubble to nothing. Once that is checked, the nozzles are then left to rest and return to room temperature earlier than the bubble is measured once once more to be able to guarantee it has returned to the original dimension inside a small tolerance.
Leak Testing
Every nozzle can additionally be stringently tested for leaks by applying 24-bar pressure for 1 hour and guaranteeing no water has escaped. It is rare for any leaks on the manufacturing line, but this is a particularly very important stage of the testing as leaks could happen if dirt is trapped inside the seal face.
Activation Testing
On a monthly basis, random nozzles are additionally examined for activation by putting the nozzle on a stress jig at various pressures and making use of warmth to the bulbs. The nozzles ought to all activate cleanly across the entire pressure vary specified to that nozzle.
A member of the production group makes use of a microscope and software program to determine the size of each bubble in the bulb.
Approvals
At Dual Mist Ltd, these checks aren’t simply to assure the standard of the production line however are additionally an important a part of the LPCB Approval. These approvals enable clients to recognise that the products they are buying are made to the best possible quality normal within the region.
The drawback to this is that the Approval Testing system can be both pricey and time-consuming – sometimes needing to be booked several months upfront and requiring years of exhausting work to realize.
The nozzles produced by Dual Mist have been put by way of their paces at BRE Global in terms of each fire testing and component/type approval.
Tamper proofing
In order to ensure that no person 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 fixed.
The nozzles are then able to be packaged and sent off for set up.
Here is an example of a control panel having been put in in The Claridges Hotel, London, UK. This is where the system is operated.
Installation
Rather than having to make use of the heavy and labour-intensive steel pipes usually used in high-pressure systems, low-pressure water techniques can use CPVC piping. This is a particular type of fire-resistant plastic enabling quick set up. Instead of threading each pipe, a heated glue can be used to rapidly construct massive pipe networks. These networks are accredited to deal with up to 12 bar strain. The nozzles are screwed into a particular pipe adaptor utilizing a half-inch gasoline becoming.
An electric control panel is fitted for the system management together 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 as soon as put in. This shows how we expect to see the nozzles as soon as a challenge has been accomplished.
Conclusion
As we are able to see there are many stages to go from metal to nozzle head with every nozzle taking a significant effort by numerous professionals to complete to the accredited normal.
Not only do water mist nozzles require multiple levels of machining and assembling, they have to additionally undergo a string of checks to have the ability to be approved for set up. Once installed, there are even further checks undergone, typically by third-party organisations in order for the complete hearth suppression system to finally be handed over to the shopper.
Water mist technology assures safety, high quality and assurance by way of the stringent testing that’s required.
With the latest publication of water mist requirements, notably in Britain over recent years, constructing developers can now be assured that the quality required for water mist techniques is now at an equivalent standard to other suppression methods.
For more info, go to www.dualmist.com
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