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Generating electrostatic charge during powder processing is almost inevitable. Wherever you have a high volume of surface contact, separation and movement – as happens when powder flows through a pipe - static electricity is naturally created.
Most powders are not good conductors of electricity, so electrostatic charges can easily build up on them, the processing equipment, isolated metal components, and other surfaces within a plant.
This generated charge is not generally hazardous unless it is allowed to accumulate, at which point it’s capable of creating a spark discharge that can ignite any flammable gasses or dusts in the environment, with potentially disastrous results. Read more about preventing combustible dust explosions.
Spark discharges can happen when there is close contact between two materials with different electrical potential ie. they are ‘charged’ differently.
In a factory, spark discharges happen when one isolated piece of equipment, like a metal pipe, becomes charged and comes close to another object, or even an operator, that has a different charge. The difference of electrical potential between the two objects can cause an electrical discharge, or spark.
This is the key reason it is so important for any factory handling bulk solids to ensure all parts of its processing systems are adequately earthed.
One vulnerable part of a bulk solids processing line is the flexible connections between processing equipment. Product flows through these connections generating electrostatic build-up on the non-conductive material (the connector).
BFM® blue band connectors are made with strong, static dissipative materials and is uniquely designed to reduce dust and static explosions.
Static dissipative materials means connectors are safer to fit and reduces the risk of static shock.
Superior materials and design mean connectors are stronger and last much longer.
Zero dust leakage and no crevices to collect product so no build-up or contamination risk.
Any reputable manufacturer will need to ensure they are complying with global safety regulations, like ATEX & IECEx, when it comes to reducing their combustible dust explosion risks.
When choosing your flexible connectors to comply with these requirements, it is important to consider that there are both process and connector design and material factors involved.
It's always advisable to keep your flexible connections as short as practically possible and to choose connectors made from a static-dissipative material. The simple reason for keeping connectors as short as possible is that the shorter the connector, the less surface area there is for static to build-up on.
Static dissipative materials help alleviate any electrostatic build-up during normal operating and drain the charge in a predictable, controlled fashion, out through the grounded pipework.
Many flexible connectors are made of materials in use in factories, like silicon and rubber which are insulative rather than dissipative, and these products are potentially dangerous options.
BFM® fitting outperform traditional hose clamp systems in virtually every processing application and condition. Here are some common process applications that are challenging for flexible connectors:
If you operate under pressure, we know keeping your product inside your process brings all sorts of challenges, usually around dust control and connector failure.
Metal Detector applications can be a challenging environment for traditional clamped connector systems because steel cannot be in near proximity to the detector.
Processors often operate equipment under negative pressure to avoid leaking product out of machinery, but you need to ensure your connectors seal properly too.
Proper cleaning of your pipes and in-line fittings is important during CIP, and having a flexible connector that can handle the chemicals and won't leak is essential.
The constant movement on sifters puts stress on flexible connections between equipment, and often causes problems like poor sealing, leaks and failures.
Whilst flexible connectors themselves can’t eliminate static build-up completel
y, static dissipative connectors like the BFM® fitting range will help reduce the chance of spark discharges occurring and potentially igniting a combustible dust explosion.
The BFM® fitting range of Seeflex products are made from a unique, ether-based polyurethane and are all designed to dissipate electrostatic build-up.
The most popular and widely used product, Seeflex 040E, has a surface resistivity of 1010 and the specialist anti-static product Seeflex 040AS rates at 108.
These Seeflex products are all strong and offer a transparent or semi-transparent transition that allows visibility of product flow.
If product visibility is not a priority, we also have breathable connectors, such as LM3 which has a surface resistivity of 108 and the most static dissipative connector in the BFM® fitting range is our pure PTFE product, Teflex NP Black, which not only tolerates high temperatures and extreme chemicals, but has an impressive surface resistivity of 106.
Get in touch with one of our local Authorized BFM® fitting Distributors to see how BFM® fitting connectors can help make your plant safer.
Earthing cables should always be installed between the top and bottom sections of piping on any transition with flexible connections to complete the earthing circuit.
These are primarily designed to prevent any electrical potential differences between the two ends of the pipework. This means in the event of a fault or earthing issue with your equipment, there won't be a spark or burst of electricity 'jumping' across your equipment and its flexible connections which could lead to an ignition or explosion.
Inside a flexible connection, electrostatic build-up still occurs even when it has earthing cables connecting the top and bottom pipe.
The constant charge being built up will naturally try to find the fastest route to earth via the nearest conductive material – the metal pipes. This can see arcing or sparks occurring within the connector itself as the charge jumps to the nearest piece of metal in an uncontrolled fashion – to then make its way to earth via the grounding cables.
This is one of the main reasons you should consider static dissipative materials for your flexible connectors.
Even with static dissipative connector materials and grounding cables, some powders being processed are so combustible that, to comply with safety requirements like ATEX, any electrical equipment within a particular radius of a transition would need to be rated to that standard.
This is as a precaution in case there is a failure of a connector and dust escapes into the immediate environment, potentially setting the scene for a combustible dust explosion if a spark were to be created by that electrical equipment.
ATEX-rated equipment can be substantially more expensive than standard versions simply because of the nature of the additional casing and sealing required to achieve this certification.
An option to solve this issue is to install an additional outer BFM® fitting ‘layer’ (see adjacent), effectively reducing the ATEX safety zone requirement to just be in between the two connectors. If the inner connector was to fail for any reason, the outer connector would contain and prevent any dust from escaping into the rest of the factory until the inner connector can be replaced.
This simple solution has saved a number of BFM® fitting customers thousands in electrical equipment costs as they weren’t required to install the high-end ATEX-rated equipment.
For more information on the ATEX rating of our products, take a look at our Certification & Compliance information.
It’s often surprising to learn that just about every product, including food, dyes, chemicals, and metals – even materials that you wouldn’t normally expect to be a fire risk in a solid-state – have the potential to become combustible in dust form.
Health and safety is paramount for global chemicals manufacturer AkzoNobel at its Elotex plant in Geleen, the Netherlands, but the construction additives produced at this plant involve fine, abrasive powders which were proving hard to contain. The resultant dust leakage posed a real explosion risk.
With Health and Safety being such a high priority for businesses today, the BFM® fitting flexible connector system provides you with peace of mind that you're improving safety for your staff.
BFM® fitting is transforming processing plants globally. Keep updated on news, products, insights and new product developments.
