Peter Swan, MD of SBES, examines an often-overlooked issue
Lone working, which often takes place in isolated areas or at unsocial times, occurs across many different sectors including construction, labs, refineries, warehouses and data/server rooms. The Office of National Statistics estimates that there are around six million lone workers in the UK.
Molten sulfur is present in an ever widening range of industries and liquid sulfur storage tanks are used worldwide in crude oil refineries and natural gas plants to store liquid sulfur in very large volumes. Sulfur storage tanks are most commonly utilised as part of the Gas Treating System in sour crude oil refineries and gas sweetening facilities to temporarily store liquid sulfur produced in the sulfur recovery plant. These tanks are usually field erected and most commonly constructed of carbon steel.
By Ulf Persson, Technical Manager (Europe), Camfil Air Pollution Control
Explosive or potentially explosive dusts are a part of many industrial processes for which dust collection systems have to be designed to work. Ideally these systems should minimise or avoid the risk of an explosion, or ensure that in the event of an explosion the outcome can be safely controlled. In this article, we explore effective ways of venting and suppression.
To download this white paper now, please visit http://www.camfilfarrapc.com/whitepapers/venting-and-suppression
Free White Paper
Dust Collectors and Explosion Safety: Isolation
By Ulf Persson, Technical Manager (Europe), Camfil Air Pollution Control
Part of many industrial processes, explosive dusts are the primary challenge for dust collection systems that are designed to minimise, avoid or control the risk of an explosion. In this white paper we explore the effectiveness of isolation.
To download this white paper now, please visit http://www.camfilfarrapc.com/whitepapers/explosion-isolation
How can you manufacture explosion-proof equipment and systems to world-class safety requirements?
Depending upon the Zone of usage, electrical, electronic and mechancial equipment intended for use in potentially hazardous environments must be independently evaluated for their impact on overall safety. The European Union’s ATEX Directive and the IECEx Certified Product Scheme are two assessment routes used for the safety of equipment used in such environments. This white paper provides an overview of these two routes and provides answers to frequently asked questions.
Why download this white paper?
Author: Greg Smith, Labtex
In this Labtex White Paper:
• Safety Storage Cabinets Overview
• What must a Safety Storage Cabinet be able to do
• A comparison of the fire resistance of cabinet constructions
• Consequences of the standard in Europe
• Approval documentation
• Conclusion
Safety Storage Cabinets Overview
The European Standard BS EN 14470-1 was implemented in April 2004 and has since been published as a national standard in many European countries including the Netherlands, France, Spain, UK, Italy etc.
In the UK it is recommended that no more than 50 litres of highly flammable solvent be stored in a room using cabinets referred to in such documents as DSEAR 2002 (Dangerous Substances and Explosive Atmospheres Regulations) and HSG 51 from the Health and Safety Executive (Storage of Flammable Liquids in Containers). These normally refer to single skinned metal cabinets manufactured according to BS 476. However, there is an exception which can be found by visiting the website: http://www.hse.gov.uk/fireandexplosion/storageflammliquids.htm
On these web pages it states that subject to a thorough risk assessment, the 50 litre recommendation can be exceeded when using high specification safety cabinets such as those manufactured according to BS EN 14470-1.
There are a number of dangers, risks and disadvantages of using an external store or any haphazard storage system.
When transporting hazardous materials from the centralised storage room to the workplace there is the risk of spillage or other incident. Precious working time is lost when collecting/returning material.
Hazardous materials which are used at the work space are not always returned to the central store and ‘hidden’ quantities of hazardous material develop. In the event of a fire these can contribute to an uncontrollable blaze and the protection of staff and fire fighters can no longer be ensured.
If unknown quantities of hazardous materials are stored, or are in use within the laboratory, applicable regulations and laws may be breached. In case of damage, insurance cover may be lost and an employer is liable for property and damage to persons. In the event of an accident, the loss of production cannot be calculated/foreseen, nor the potential long term loss of reputation.
Safety, protection and the advantages of a workplace with a fire resistant safety storage cabinet
The time spent ‘fetching and carrying’ from the storage room to the workplace is minimised and all hazardous materials for daily use can be readily available safely and conveniently in the lab. There is increased efficiency as there is no need to move flammables in and out from the central storage room.
Type 90 safety cabinets in accordance with EN 14470-1 provide the highest degree of safety for personnel and the environment and give maximum safety to your investment. They guarantee the highest fire protection available today, minimise the potential for explosions and prevent an existing fire from spreading.
A type 90 cabinet provides sufficient time for personnel to safely leave the building and for fire fighters to rescue people from the building and to extinguish a fire.
What must a Safety Storage Cabinet be able to do?
The following points describe the basics and main safety, test and construction requirements.
The primary protection for which a safety storage cabinet is intended is to shield stored, hazardous materials from a temperature rise of more than 180K in the event of fire for the defined period of time.
Combustion may begin if the temperature rise inside the Safety Storage Cabinet exceeds 180K. From this value up, the majority of chemicals reach their ignition temperature and they explode.
Fire is the same in all parts of the world!
Whether in London or Lisbon, a fire has the same properties and temperatures. A temperature curve shows that after only 5 minutes a fire has reached a temperature of 576°C. After 30 minutes, 842°C has been reached, and after 90 minutes the flames are at more than 1000°C.
The contents of a single skin storage cabinet to BS476 will follow the same temperature curve.
A comparison of the fire resistance of cabinet constructions
A double-wall steel cabinet provides no more than three minutes of protection before the interior has heated to 180°C.
A Type 30 EN Safety Storage Cabinet provides 30 minutes of protection before the interior has heated to 180°C. 10 times more safety in the event of fire compared with a double-wall steel cabinet.
Highest safety is achieved with a Type 90 EN Safety Storage Cabinet. These cabinets provide 90 minutes of protection before the interior has heated to 180°C.30 times more safety in the event of fire and enough time for rescue and fire fighting services to take action.
Fire protection
In the event of a fire the cabinet must ensure that, over a period of time defined by the manufacturer (but in any event at least 15 minutes), its contents do not present an additional risk that the fire will spread. The cabinet doors must close entirely, starting from any position (closing time max. 20 seconds).
Air inlet and outlet openings
The cabinets must have openings for air inlet and outlet (for connection of the cabinet to an exhaust system). The ventilation openings must close automatically at a temperature of 70 °C. Shelves and drawers must be able to support the loading specified by the manufacturer over the period of the test in the furnace. Design evidence of the load-carrying capacity of shelves and drawers in the event of fire based on EN 1365 (fire resistance tests for self-supporting components). The internal equipment of the cabinet must include a spill containment sump and the spill containment sump must retain its ability to function after the fire resistance test. This is to be checked visually by filling the spill containment sump with water.
Fire resistance
Each model must be independently verified by tests on a design sample. The fire resistant cabinet is exposed to flames in a suitable furnace. The doors, walls and ceiling of the cabinet being tested must be exposed to the same heating conditions.
Cabinets must be tested as free-standing single cabinets. The flame exposure is carried out in accordance with the standard temperature curve of BS EN 1363-1 (5.1.1).
The temperature rise is measured inside the cabinet.
The cabinet will then be classed as type 15, 30, 60 or 90, according to the time that has elapsed before the temperature rose by 180 K.
EN 14470-2. The standard for gas cylinder cabinets
Maximum safety in the storage, provision and withdrawal of gas cylinders in indoor areas.
Due to the positive pressure and the contents (corrosive, toxic, inflammable, fire accelerating), gas cylinders represent a hazard potential. It is therefore usually recommended to store gas cylinders in outdoor areas. In practice this is often not possible or is associated with very high costs.
With the publishing of the new European standard for gas cylinder cabinets, EN 14470-2, an economical and flexible option for the installation of gas cylinders in indoor areas is now available that offers a level of safety comparable to that of outdoor storage.
Consequences of the standard in Europe
Fire resistance is classified into 4 classes from G15 up to G90 (fire resistance of 15 up to 90 minutes).
Each type of cabinet and each cabinet size must to be type tested in a furnace. In case dimensional variation exceeds the tolerance, the cabinet has to be retested again. Tests can only be executed by an authorised material testing institute. Cabinets must be tested in a furnace as free-standing single cabinets.
BS EN 14470-2 stipulates declaration of conformity or certificates of conformity be supplied with each cabinet delivery.
Approval Documentation
Complete approval documentation for each safety storage cabinet includes:
1. A test report of an authorised material testing institute stating/proving the successfully passed fire test.
2. Test certificate by an independent testing organisation and declaration of CE conformity by the manufacturer
This ensures compliance with regulations, safety for the user and clear identification of approval documents with the model of safety storage cabinet.
asecos - Standard for safety and quality
1. Testing certificates of an authorised material testing institute for each cabinet. Approved fire resistance in accordance with EN 14470-1.
2. Verification for all cabinet models on observing the Equipment and Product Safety Law. Documented in the testing certificates by independent testing organisations.
3. CE approval certificates for each cabinet model. Verification that all relevant European guidelines are observed.
4. Quality Management in accordance to DIN EN ISO 9001. Asecos quality from the quotation to the delivery.
Conclusion
BS EN 14470-1 and BS EN 14470-2 are product specifications giving performance requirements of safety cabinets for internal storage of flammable and other hazardous products.
For maximum safety, efficient working practises and to keep one step ahead of legislation these cabinets have no equal.
Contacts
Labtex is a specialist laboratory and process chemistry equipment solutions provider.
A dynamic team of professionals with expertise in research and process development across a wide range of industries and disciplines.
You will find that talking to Labtex is a breath of fresh air. No complicated telephone system, just real people ready to react professionally to your enquiry. We pride ourselves on our customer service based on quick response, accurate informed advice and attention to detail.
Labtex,
Dogley Mills, Penistone Road, Fenay Bridge, Huddersfield,
West Yorkshire, United Kingdom HD8 0LE
Tel: 01484 600200
Fax: 01484 607390
Email: This email address is being protected from spambots. You need JavaScript enabled to view it.
Web: www.labtex.co.uk
Close collaboration between two Northumberland engineering companies has resulted in the production of a unique marine vessel which is certified for work in the most extreme Hazardous Areas.
Blyth-based Alnmaritec, the UK’s premier commercial boat builder, and the nearby Ashington-based A-Belco Group joined forces for the production of a line and hose handling boat which is to be installed on the FPSO (Floating Production, Storage and Offloading) vessel, N’GOMA, currently under construction at the Keppel shipyard in Singapore, but due to be stationed off the Angolan coast from 2014.
The twin diesel engine vessel, the 25th ‘Wave Handler’ class boat Alnmaritec has produced, has been designed primarily for line and hose handling duties with a small wheelhouse forward with folding seating for four passengers and a bow access arrangement for personnel transfers. The aft deck is fitted with a working platform at the stern to facilitate hose/line handling with a hydraulic capstan built into a plinth on the deck and a towing point with a remotely operated quick release hook.
The boat is actually based on board the FPSO and launched by davits. As such, all electrical fittings had to ATEX certified for use Zone 1 Hazardous Areas – the potentially explosive atmosphere on an FPSO requires the most stringent standards of electrical safety.
Alnmaritec’s Operations Director, Andy Clark, commented, “We’d designed and constructed such vessels before but had always had problems with suppliers of the electrical equipment which are so important on projects like this. We were therefore delighted to find the A-Belco Group virtually on our doorstep and they have been incredibly helpful throughout the whole design and production process.”
“We’ve turned the original enquiry from our customer, Single Buoy Moorings Limited of Monaco, around to handover of the boat in just 16 weeks and, whilst our design of aluminium boat is now the industry standard, the help we had from A—Belco on the ATEX certified electrical systems, enabled us to meet the customer’s target.”
On board the boat, all electrical fittings are ATEX certified, from the battery charging sockets, the wiring assemblies and including even the LED external lights that enable the boat to work at night.
A-Belco Hazardous Area Sales Administrator, Janice Taylor, added, “The boat contains not only items from our Hazardous Area Products Division, but also light fittings from the Hadar Lighting Division, including the very latest LED floodlights. We’re delighted to have been of assistance to Alnmaritec and look forward to being ‘good neighbours’ on many such projects!”
Further details of the A-Belco Group and their manufacturing divisions is available at www.a-belco.co.uk.
The challenge of safely and economically dealing with rainwater and petrochemical spills in ATEX Zone 0 areas is growing as more stringent monitoring controls come into place for Tank Storage Terminals, particularly in European countries. Certain ATEX Zone I areas within these terminals have been re-defined as ATEX Zone 0 areas, requiring a review of their risk assessment but also providing an opportunity for pump manufacturers
CRANE® Process Flow Technologies GmbH in Dusseldorf, Germany, are reporting an increasing number of enquiries for their DEPA® Air Operated Double Diaphragm (AODD) pumps which are certified for ATEX Zone 0 use by Physikalisch-Technische Bundesanstalt, Germany. The pumps, which can be air or nitrogen powered, eliminating the requirement for monitoring control systems, are proving particularly suitable for Tank Storage Terminals.
Dedicated to developing innovative hydrokinetic turbines to generate “green” energy from the motion of the sea, Irish company Tidal Energy Limited (TEL) recently had a pressing need for a way of accurately of measuring the power produced by its scale-model prototypes. Equipment from Sensor Technology provided a convenient and dependable solution where other methods had failed.
TEL was established in 2008 by Marine Scientist, David Baird, and Civil Engineer, John Lambe, who realised that the growing demand for renewable energy sources meant that there would be good market for efficient and cost-effective marine hydrokinetic turbines. They resolved to pool their expertise to develop suitable products, using a low cost approach – instead of expensive tow tanks for prototype testing, TEL would use its existing resources, including boats and moorings, and would test their prototype turbines under real operating conditions in the open sea.
When it came to measuring the power produced by the turbines, however, TEL found that it had a problem. In order to calculate the power, it needed to be able to measure both the rotational speed of the turbine shaft and the torque being transmitted by the shaft. While the speed measurement was straightforward, measuring the torque accurately presented rather more of a challenge.
Initially, the company used a de Prony Brake system for torque measurement. This essentially relies on measuring the force produced in a friction band around the shaft. Unfortunately, this system, while simple, was cumbersome to work with and, in addition, its numerous inherent sources of error meant that TEL was unable to achieve the required level of accuracy in its measurements.
A better solution proved elusive, however, particularly as the torque measuring system would need to operate in a wet and salty marine environment. Ultimately, after searching the market for a cost-effective product that would meet its needs, TEL found the RWT410/420 series of TorqSense rotary torque sensors from Sensor Technology.
These innovative sensors are available in three different body sizes and six different shaft sizes, covering torque measurements from 1 Nm to 13,000 Nm, which made it easy for TEL to choose a sensor that exactly met its requirements.
Like all of the sensors in the TorqSense range, the RWT410/420 series uses novel sensing technology that depends for its operation on surface acoustic wave (SAW) transducers. These transducers comprise two thin metal electrodes, in the form of interlocking “fingers”, on a piezoelectric substrate such as quartz. When an RF signal of the correct frequency is applied to the transducer, surface acoustic waves are set up, and the transducer behaves as a resonant circuit.
The essential feature, however, is that if the substrate is deformed, the resonant frequency changes. When the transducer is attached to a drive shaft, the deformation of the substrate and hence the change in resonant frequency is related to the torque applied to the shaft. In other words, the transducer, in effect, becomes a frequency-dependent strain gauge.
Since the transducers operate at radio frequencies, it is easy to couple signals to them wirelessly. Hence, TorqSense sensors that incorporate the SAW transducer technology can be used on rotating shafts, and can provide data continuously without the need for the inherently unreliable brushes and slip rings that are often found in traditional torque measurement systems.
In addition to accurately measuring shaft torque, the sensors also measure rotational speed and, by combining these two measured values internally, they can produce an output that directly indicates shaft power, which was exactly what was needed in the TEL application. TorqSense sensors also feature robust sealed construction, allowing them to operate reliably in marine and other challenging environments.
In the TEL application, the RWT410/420 sensor is used in conjunction with Sensor Technology’s TorqView software package. This runs on a laptop PC that is taken on board the boat when the scale-model hydrokinetic turbines are being tested, and provides a direct real-time readout of the power produced by the turbine. The software also logs data from the sensor so that this can be analysed further after the test has been completed.
“We’ve now been using the TorqSense sensor for over two years,” said David Baird of TEL, “and it’s proving absolutely invaluable in our work. It’s easy to use, it’s reliable, and it consistently delivers accurate results that are playing a key role in helping us to refine the design of our hydrokinetic turbines. In short, it’s an exceptionally useful product, and I have no hesitation in recommending it.”
Sensor Technology Ltd
Tel: +44 (0)1869 238400 Fax: +44 (0)1869 238401
Web: www.sensors.co.uk
Email: This email address is being protected from spambots. You need JavaScript enabled to view it.
As one of the most famous and prestigious names in the engineering and bearing manufacturing world, SKF is always very conscious to embrace the very best of safety technology, and this policy has been tangibly reflected by the recent installation 