Identifying Leaks from Natural Gas Pipelines at a Safe Distance

The use of natural gas, of which methane is the principle component, is increasing worldwide. According to the American Petroleum Institute methane meets 24% of U.S. energy demand and heats over 50% of all U.S. households. It also has many industrial uses, such as the manufacture of chemicals like ammonia, methanol, butane, ethane, propane and acetic acid; it is also an ingredient in products as diverse as fertilizer, antifreeze, plastics, pharmaceuticals and fabrics.

Natural gas is transported in several ways: through pipelines in gaseous form; as liquefied natural gas (LNG) or compressed natural gas (CNG). LNG is the normal method for transporting the gas over very long distances, such as across oceans, while CNG is usually carried by tanker trucks over short distances. Pipelines are the preferred transport choice for long distances over land (and sometimes offshore), such as between Russia and central Europe. Local distribution companies also deliver natural gas to commercial and domestic users across utility networks within countries, regions and municipalities.

Trans-Alaska pipeline

Trans-Alaska pipeline

Natural gas is extremely combustible and we have all seen in the news what happens when safety is compromised. Just recently in Manitoba, Canada, thousands of people were left without heating after a huge natural gas pipeline explosion. In another instance, an apartment building was destroyed in Birmingham, Alabama due to a leak in a natural gas distribution pipe. Gas leakage is also wasteful. It is estimated that fugitive natural gas emissions can be as much as 15% in some countries.

Regular maintenance of gas distribution systems is clearly essential. Identifying and rectifying gas leaks is also an integral part of any maintenance programme, but it is notoriously difficult in many urban and industrial environments, as the gas pipes may be located underground, overhead, in ceilings, behind walls and bulkheads or in otherwise inaccessible locations such as locked buildings. Until recently, suspected leaks from these pipelines could lead to whole areas being cordoned off until the location of the leak was found.

Precisely because conventional gas detectors – such as those utilising catalytic combustion, flame ionisation or semiconductor technology – are not capable of remote gas detection and are therefore unable to detect gas leaks in hard to access pipelines, there has been a lot of recent research into ways of detecting methane gas remotely.

Remote Detection
Cutting edge technologies are now becoming available which allow the remote detection and identification of leaks with pinpoint accuracy. Hand-held units, for example, can now detect methane at distances of up to 100 metres, while aircraft-mounted systems can identify leaks half a kilometre away. These new technologies are transforming the way natural gas leaks are detected and dealt with.

LaserMethane mini remote gas detection from pipelines

LaserMethane mini remote gas detection from pipelines

Remote sensing is achieved using infrared laser absorption spectroscopy. Because methane absorbs a specific wavelength of infrared light, these instruments emit infrared lasers. The laser beam is directed to wherever the leak is suspected, such as a gas pipe or a ceiling. Because some of the light is absorbed by the methane, the light received back provides a measurement of absorption by the gas. A useful feature of these systems is the fact that the laser beam can penetrate transparent surfaces, such as glass or perspex, so it may be possible to test an enclosed space prior to entering it. The detectors measure the average methane gas density between the detector and target. Readings on the handheld units are given in ppm-m (a product of the concentration of methane cloud (ppm) and path length (m)). In this way, methane leaks can be quickly confirmed by pointing a laser beam towards the suspected leak or along a survey line, for example.

An important difference between the new technology and conventional methane detectors is that the new systems measure average methane concentration, rather than detecting methane at a single point – this gives a more accurate indication of the severity of the leak.

Applications for hand-held devises include:

  • Pipeline surveys
  • Gas plant
  • Industrial and commercial property surveys
  • Emergency call out
  • Landfill gas monitoring
  • Road surface survey

Municipal Distribution Networks
The benefits of remote technology for monitoring pipelines in urban settings are now being realised.

The ability of remote detection devices to monitor gas leaks from a distance makes them extremely useful tools in emergencies. Operators can stay away from potentially dangerous leak sources when checking the presence of gas in closed premises or confined spaces as the technology allows them to monitor the situation without actually gaining access. Not only is this process easier and quicker, but it is also safe. Moreover, it is not affected by other gases present in the atmosphere since the detectors are calibrated to only detect methane – therefore there is no danger of getting false signals, which is important in emergency situations.

Natural gas distribution centre

Natural gas distribution centre

The principle of remote detection is also applied when inspecting risers (the above-ground pipes carrying gas to the customers’ premises and normally running along the building outside walls). In this case, the operators point the device towards the pipe, following its route; they can do this from ground level, without having to use ladders or access the customers’ properties.

Another useful application relates to pressure regulating stations – checking valves, fittings and pipes inside a station for possible gas leaks becomes quicker and more accurate than with traditional methods.

One leading gas distribution system operator, with a total network of about 52,000 kilometres of gas mains pipelines, has recently adopted hand-held devices based on this technology for use across its gas distribution networks in Italy. They recently completed a two-year trial with the portable unit in a number of cities all over the country, during which devices were tested under a variety of operating conditions and in all weathers to see whether they were up to the task of detecting gas leaks in difficult urban situations. The result of this was the adoption of the method as part of the company’s routine gas leak monitoring.

Hazardous Areas
In addition to detecting gas leaks from municipal distribution networks, explosion-proof, ATEX approved devices can be used in Zone 1 hazardous areas such as petrochemical plants, oil refineries, LNG terminals and vessels, as well as certain mining applications.

When inspecting an LNG/LPG underground tank, for example, an explosion-proof device would be required within 7.5 metres of the tank itself and one metre around the safety valve. Operators therefore need to be fully aware of these restrictions and equipped with the appropriate equipment type.

GPS Coordination
Some instruments now allow spot methane readings to be taken at various points around a site – such as an LNG terminal – automatically generating GPS tracking of the measurement readings and locations. This makes return trips for additional investigations far more efficient, while also providing a bona-fide record of confirmed inspection activity – often a prerequisite for regulatory compliance.

Aerial Detection
Moving beyond hand-held devices, there are also remote methane detectors which can be fitted to aircraft and which detect leaks from gas pipelines over hundreds of kilometres. These systems can detect methane levels at concentrations as small as 0.5ppm up to 500 metres away and include a real-time moving map display of gas concentrations as the survey is conducted.

Gas Processing Plant from the air

Gas Processing Plant from the air

The way these systems work is relatively simple. A remote detector is attached beneath the aircraft’s fuselage (usually a helicopter). As with the handheld device, the unit produces an infrared laser signal, which is deflected by any methane leakage within its path; higher methane levels result in more beam deflection. These systems also utilise GPS, so the pilot can follow a real-time moving map GPS route display of the pipeline, with a real-time display of aircraft path, gas leaks and concentration (in ppm) presented to the crew at all times. An audible alarm can be set for a desired gas concentration, allowing the pilot to approach for closer investigation.

Conclusion
The range of remote methane detection systems is increasing rapidly, with new technologies being developed all the time. All these devices, whether hand-held or fitted to aircraft, allow quick, safe and highly targeted identification of leaks – whether beneath the pavement in a city or across hundreds of kilometres of Alaskan tundra. This not only helps prevent wasteful and costly emissions – it also ensures personnel working on or near the pipelines are not exposed to unnecessary danger.

Because the use of natural gas is increasing worldwide we foresee rapid technological advances in remote gas detection in applications as diverse as leak survey, transmission integrity, plant and facilities management, agriculture and waste management, as well as process engineering applications such as coke and steel production. Each of these areas have situations where access may be difficult, combined with the need to put personnel protection at the top of the agenda. Opportunities for remote methane detectors are therefore growing all the time.

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Dependable Detection of Refrigerant Gases with Crowcon’s F-Gas Detector

Fluorinated (Freon) gases, which include hydrofluorocarbons (HFCs), perfluorocarbons (PFCs), hydro-chlorofluorocarbons (HCFCs) and sulphur hexafluoride (SF6), are a family of man-made chemicals containing fluorine. These ’F-gases’ are extremely powerful greenhouse gases that trap heat in the atmosphere, contributing to global warming – most are between 1,000 and 20,000 times more powerful than CO2 in terms of their impact on the atmosphere.

Dependable Detection of Refrigerant Gases (Freons) with Crowcon F-Gas Detector

Dependable Detection of Refrigerant Gases (Freons) with Crowcon F-Gas Detector

Not only are F-gases harmful to the environment, they are also extremely toxic and represent a significant health risk if inhaled. SF6 also poses an asphyxiation risk as, once inhaled, it may be too heavy to expel from the lungs.

In EU, the use and emission of F-gases comes under Regulation 842/2006, which mandates leakage control and regular checks. Leakage checks must be carried out by certified personnel for all plant with equipment containing 3kg or more of F-gases. Frequency of leak checks depends on the amount of refrigerant charged. In addition, detailed records must be kept in a log book – failure to comply may lead to severe penalties.

Common uses of F-gases include:

  • Refrigeration and air conditioning systems
  • Heat pumps
  • Aerosols
  • Fire-fighting equipment
  • High voltage, gas-insulated switchgear

There are also many industrial applications including magnesium smelting, electronics manufacture and insulating foam manufacture.

Effective monitoring and detection of these gases is essential. Crowcon’s F-Gas infrared detector is a fixed-point detector specially calibrated to detect a wide range of F-gases. Rugged and easy to install, it can be connected to any control system which accepts analogue signals. Together with Crowcon’s Gasmaster control panel and Xgard toxic gas detector, the F-Gas detector provides an effective gas leak detection package.

In addition to protecting personnel from toxic gas risks, installing the F-Gas detector also offers the following benefits:

  • Provides an early warning that the gas is leaking and thus maintains system efficiency and reduces potentially huge gas replacement costs
  • Enables the supplier and user to comply with the mandatory F-gas regulations
  • Helps to reduce the risk of leakage of powerful greenhouse gases into the environment

The detector operates from 24Vdc nominally and provides a 4-20mA signal (the output can also be set to 0-20mA, 0-2V, 0-5V or 0-10Vdc). It is compatible with most control systems or 4-20mA type controller. Housed in a rugged IP54 enclosure, the detector is suitable for use in non-hazardous areas such as plant rooms or switchgear rooms. With no moving parts, very little maintenance is required – just a bi-annual gas check (with re-calibration if necessary).

Special features of the F-Gas detector include:

  • Superior IR sensor technology: provides fast, stable and dependable performance with low maintenance and long life. Unlike semi-conductor type sensors, the F-gas detector is not affected by other types of gas or changes in temperature or humidity
  • LED indicators: tri-coloured LEDs indicate the operating status of the detector and, in combination with the function keys, facilitate simple adjustments such as zero and calibration
  • Choice of signals: the analogue output signal can be set as 4-20mA, 0-20mA, 0-2V, 0-5V or 0-10Vdc for compatibility with virtually any control system
  • IP54 rated enclosure: provides good protection from dust and water ingress in indoor environments

More information about the EU regulations can be found at:
https://www.gov.uk/managing-fluorinated-gases-and-ozone-depleting-substances
http://www.fluorocarbons.org/

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Crowcon’s Gas-Pro PID Protects Workers from VOCs and H2S

Photo-ionisation detection finds toxic compounds at very low concentrations

Crowcon’s new Gas-Pro PID portable gas detector, part of the popular Gas-Pro range, detects a wide range of volatile organic compounds (VOCs) found in many industrial applications.

Crowcon’s new Gas-Pro PID portable gas detector

Crowcon’s new Gas-Pro PID portable gas detector

VOCs are not only highly flammable, they also pose a significant toxic hazard at very low concentrations – well below the lower explosive limit (LEL) of the VOCs. H2S, also detected by PID, is likewise extremely toxic at very low concentrations.

Materials containing VOCs include acetone, benzene, paints, solvents, degreasers, plastics, resins and certain fuels – these occur in industries ranging from petrochemicals, oil refining, pulp and paper and aviation. H2S often occurs in oil refineries in a toxic mix with VOCs.

The Gas-Pro PID is specifically designed to detect and warn of these dangerous compounds well below the concentrations that they become toxic. Key benefits include:

  • Top-mount, easy-to-read display for quick decision making
  • Ergonomic design
  • Monitors up to five gases
  • PID correction factor – set to target VOCs
  • Broad range PID which detects hundreds of gases
  • +ve Safety™; tri-colour status indication
  • Water and dust resistant to IP65

Industries where the Gas-Pro PID can be used include:

  • Oil Refining
  • Petrochemicals and Chemical
  • Pulp and Paper
  • Aviation
  • HazMat teams investigating suspected VOC spillages

For more information please visit the Gas-Pro PID page on Crowcon’s website.

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Wireless Gas Detection with Crowcon’s Detective Net

Wireless module works with Crowcon’s Detective+ transportable gas detectors

Crowcon’s new Detective Net wireless module allows up to 25 Detective+ gas detectors to be linked without cables. It is ideal for use in the oil, gas, petrochemical and utility industries.

Crowcon’s new Detective Net wireless module allows up to 25 Detective+ gas detectors to be linked without cables.

Crowcon’s new Detective Net wireless module allows up to 25 Detective+ gas detectors to be linked without cables.

The Detective+ is a free-standing, transportable multigas monitor that can be used individually or in groups to monitor up to four gases at once. By using the Detective Net module, up to 25 Detective+ units can be linked wirelessly and positioned as much as 100 metres apart. Should wireless connection between two of the detectors weaken, the RICOCHET® wireless network will ‘self-heal’ and automatically re-route communications via alternative devices. This creates a ‘mesh’ type network, ensuring greater reliability in safety-critical situations.

Over a dozen gas sensor options are available with the Detective+, including infrared sensors for flammable gas that are immune to the poisoning effects which plague standard flammable gas sensors. If a dangerous gas level is detected, the Detective+ unit warns with a wailing 104 dBA siren and flashing, high intensity LED beacons which are  visible from all angles. A signal is also sent to all the other units, alerting workers to the danger. In addition Detective Net transmits other fault information such as loss of signal or low battery power.

If the signal is very weak, for example because of thick metal bulkheads, Detective Net can act as a repeater to boost the signal between units. A cable can even be used to extend the reach of an individual Detective+ unit and put it in a position with a stronger wireless signal – this is especially useful in cramped, confined spaces.

The Detective+ is indeed ideal for confined spaces, ensuring safe gas levels before workers enter and monitoring continuously during welding and other repair work.  With 60 hours of battery operation, work can go on with a minimum of detector recharging, keeping shutdown time as short as possible.  In commissioning new liquefied natural gas (LNG) plants, the Detective+ can be placed along the pipelines to check for leaks, minimising explosion risks.

The rugged tripod construction and raised profile keeps the Detective+ sensors away from obstructions and surface water.  An integral safety cage gives extra protection in the event of the unit being overturned in chaotic work areas.  An operating temperature range of -20°C to +40°C assures reliable detection in a variety of environments.  The units are Class 1 Division 1 Groups A, B, C, and D approved.  Optional folding legs facilitate compact storage and transportation.

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Breaking New Ground in Gas Detection

Work on world class new facility for Crowcon Detection Instruments commences at Milton Park, Didcot, UK

Gas detection specialist Crowcon today celebrated the official ground breaking for its new 40,000 square foot facility at the prestigious Milton Park in Didcot, UK.

Gas detection specialist Crowcon today celebrated the official ground breaking for its new 40,000 square foot facility at the prestigious Milton Park in Didcot, UK.

Caption: Crowcon Directors Mike Ophield (right) and Barry Swift (second left) celebrate with MEPC Directors James Dipple (left) and Andrew Barlow (second right).

Gas detection specialist Crowcon today celebrated the official ground breaking for its new 40,000 square foot facility at the prestigious Milton Park in Didcot, UK.

Having outgrown its current headquarters location in Abingdon, the Milton Park facility will house all existing functions as well as provide extensive customer training and product demonstration facilities, an additional 30% of manufacturing space and a full service calibration laboratory.

As he took charge of the first shovel-load of earth at the site, Mike Ophield, Managing Director of Crowcon, said: “Following two years of planning I am really delighted to see this facility reach the ground breaking stage. I would like to thank the combined team from Crowcon and MEPC for bringing us so smoothly to this exciting first step”.

“As we are an international company, we are fortunate that Milton Park is both a hub for science and innovation and an excellent location with great transport links”, Mike continued.  “But, in selecting a site, it was also very important for us to find a location where we could retain our highly-valued workforce and continue our commitment to local employment.  As Milton Park is only five miles from our current location we are pleased to have achieved this. With this investment we are demonstrating our confidence in the future of the Crowcon gas detection business worldwide.”

Andrew Barlow, Commercial Director at MEPC, added: “This is great news for Oxfordshire’s growth story. We have worked closely with Crowcon to design a bespoke building which will combine modern production facilities alongside contemporary office accommodation.  Together with the first-class setting and amenities on the Park, the new premises will provide an excellent environment for staff and visitors alike. This is part of an exciting development programme already underway on Milton Park’s Enterprise Zone land.”

Completion and relocation of current staff and equipment is anticipated during the fourth quarter of 2014.

About Milton Park and MEPC
Milton Park is home to 6,800 people and over 200 organisations. MEPC is the long-term owner, manager and developer of Milton Park and, with its team located on-site, it is committed to delivering the highest level of service for its customers. For more information, please contact the MEPC team on 01235 865555 or visit the website at www.miltonpark.co.uk.

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Crowcon’s New and Enhanced Modular Gasmaster Control Panel Showcases New Features and Benefits

Crowcon’s new Gasmaster control panel has a modular design meaning users only need purchase the required number of input modules. It can easily be extended by adding more modules at a later date. Gasmaster monitors up to four gas detectors or four fire zones, all from a single location.

Crowcon’s Modular Gasmaster Control Panel Monitors up to Four Gas Detectors

Crowcon’s Modular Gasmaster Control Panel Monitors up to Four Gas Detectors

Simple to operate, the large multilingual LCD display shows gas levels from all detectors simultaneously and allows quick and easy system adjustment and testing from the control panel. It can operate as a stand-alone unit or interface with any alarm or visual warning devices and control systems.

In addition to standard 4-20mA-type gas detectors, Gasmaster can also be used with mV pellistor-type flammable gas detectors, which are significantly lower in cost than 4-20mA-types as they have no internal electronics. Sensor calibration is performed via the Gasmaster user interface: once commissioned, mV pellistor-type detectors do not need to be accessed until the sensor needs replacing – usually 3-5 years after installation. In addition, power to mV pellistor-type detectors is automatically cut if the gas reading exceeds 95% of the gas’ LEL (Lower Explosive Limit) to prevent sensor damage.

Gasmaster provides as standard a wide range of analogue, relay and Modbus outputs and a ‘calibration due’ warning informs the user when a service is due on a gas or fire detector. An IP65 enclosure also means the control panel can be installed in potentially wet areas without requiring the additional cost of high-IP enclosures.

Key industries include:

  • Refineries
  • Petrochemical, chemical and pharmaceutical plants
  • Water and wastewater treatment
  • Gas storage and distribution
  • Power generation
  • Manufacturing processes (e.g. car manufacturing plants)
  • Universities and research facilities
  • Local authorities

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Crowcon’s I-Test Ensures Gas Detectors are Compliant

Bump testing & calibration station tests and verifies Crowcon Gas-Pro detectors

The new Crowcon I-Test bump testing and calibration station is designed specifically to test and verify that Crowcon’s Gas-Pro portable gas detectors are in a compliant state. Bump testing (gas testing) standards globally are becoming ever-stricter and the demands on fleet managers to control bump and calibration records are increasingly stringent. The I-Test simplifies this process as much as possible.

The Crowcon I-Test bump testing and calibration station

The Crowcon I-Test bump testing and calibration station

To start with, there’s no need to turn the test gas on and off – a flow regulator automatically pulls in the correct amount and concentration of gas for each bump.  The I-Test also starts automatically as soon as a Gas-Pro detector is inserted without the need to press any buttons. The device then verifies that all gas sensors are responding to a known value of gas and that the filters are clear and good for use.  It also tests that audible and visual alarms are working, giving the user full confidence that a unit is compliant for site use. In addition, the I-Test informs the operator if a gas cylinder is empty or has expired.

The accompanying I-Test Manager software tracks which Gas-Pro units need calibrating and allows storage, interrogation and convenient presentation of large amounts of bump testing data. Calibration certificates are automatically created and stored and many different types of reports and graphs can be created for easy interpretation. All this information is then easily accessible for audit and compliance purposes.

The Crowcon I-Test allows a fleet manager to do the following:

  • Change alarm levels on each sensor
  • Control calibration gas and lot numbers
  • Set up banners on the display
  • Set calibration information and store results
  • Set bump test information and store results
  • View event and data logs and run reports
  • Print calibration and bump certificates
  • Run and print exception reporting
  • Customise reports and save to databases

These are just the main features, but the I-Test has a lot of flexibility and each site manager can determine what’s important for their site. Once these features are set up for the first time the system can then manage an entire fleet of Gas-Pro detectors.

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What are the Seven Deadly Sins of Gas Detection? Find out from Crowcon at the A+A trade fair!

What are the Seven Deadly Sins of Gas Detection? If you want to know you should get down to Crowcon’s booth (6J24) at the A+A Trade Fair and Congress in Düsseldorf this November.

What are the Seven Deadly Sins of Gas Detection? Find out from Crowcon at the A+A trade fair

What are the Seven Deadly Sins of Gas Detection? Find out from Crowcon at the A+A trade fair

Not only can you learn about the Sins, you can also see Crowcon’s new range of gas detection technology which includes Gas-Pro, the multigas portable monitor ideally suited for confined space work. This is now supported by the brand new I-Test and Q-Test gas test and calibration systems which offer extensive reporting capabilities, also on the stand.

In addition you’ll be able to see the newly upgraded Gasmaster control panel which is now available in one, two, three or four-module formats. Crowcon will also be demonstrating Detective Net. This new module provides ‘self-healing’ wireless network capabilities for the Detective Plus temporary area monitoring system.

So if you want to know about gas safety, come and talk to the experts at Crowcon.

A+A is the world’s largest, specialist trade fair for the safety and security industries and is held between 5-8 November.

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Bump testing doesn’t have to be a headache

There are many reasons why a portable gas detector may not to react to gas, some of which may not be evident to the user. The safest way to make sure a gas monitor is working at its optimum is to regularly test the unit. This is known as a gas or ‘bump’ test.

Crowcon's C-Test makes bump testing quick and easy.

Crowcon’s C-Test makes bump testing quick and easy.

The following scenario highlights the importance of bump testing:
Peter works at a local oil refinery and arrives on site in the morning to carry out his daily tasks. He wears all the safety equipment required for safe site entry: safety boots, fire resistant overalls, hardhat, ear defenders, safety glasses and a single gas hydrogen sulphide (H2S) gas monitor. His job for that day is to carry out some heavy cleaning around the site using a jet washer.

At the end of his shift he returns to the changing room to clean up. He notices that some of his equipment is dirty and cleans it using cleaning agents containing alcohols and silicones.

The next day he arrives on site as usual and gathers his equipment before getting briefed on his work schedule. Later that day he is working in a low-lying area when he smells something similar to rotten eggs, but the smell quickly passes and, as his gas monitor did not react, he continues working. Not long afterwards he suddenly collapses after being overcome by high levels of H2S.

Luckily, Peter’s colleague John sees him fall and rushes to his aid. As John approaches Peter, his H2S gas monitor goes into alarm. Following the correct site procedure, he immediately calls for safety personnel equipped with breathing apparatus to rescue Peter, who is luckily unscathed but has to take two weeks off work to recover.

What are the lessons to be learnt in this scenario?
The refinery where Peter works provided all the equipment required to keep him as safe as possible. The situation was created by Peter himself – a situation that could have easily been avoided if he had followed correct procedures.

Cleaning his equipment, including the gas monitor, with cleaning products that contain alcohols and silicones was Peter’s first mistake. Sensors can become poisoned or inhibited with these types of cleaning agents. Alcohol cleaning agents can also damage electro-chemical sensors, and silicone-based products should never be used with catalytic bead sensors intended for measuring hydrocarbons such as methane, pentane and propane. The silicone attaches itself to the active bead and heat causes a film to form around the active bead, disabling its ability to react to potential gases. Consequently, most hydrocarbon gases would not be detected and the unit would not react. The circuit, however, will still be complete – so the unit will continue to give a normal output to the user who would think it was working normally. This risk can be avoided by carrying out regular bump tests.

To check the lower explosive limit (LEL) sensor for silicone poisoning, first apply methane (CH4 50% LEL) to the unit. If the unit reacts, this indicates that the sensor is not poisoned and the unit is safe for use. If, however, the unit does not react, apply hydrogen (H2 50% LEL) to the sensor. If the unit responds to the hydrogen gas but not methane, then the unit has been poisoned by silicone.

Note that while most LEL sensors are fitted with a silicone resistant filter, this will only protect the sensor to a certain extent. Also, be careful when choosing the type of LEL sensor, as sensors with silicone filters will not detect, or have a slower response to, larger hydrocarbons such as ethanol, methanol and nonane. All reputable gas detection equipment manufacturers will be able to recommend the best solution for your circumstances.

What should Peter have done differently?
He should have referred to the gas monitor’s manual, which would have instructed him to clean the unit by using warm water only or, if necessary, with a cleaning agent that does not contain alcohols or silicones. Gas equipment manufacturers can provide additional guidance on the specific types of cleaning agents that can be used.

After cleaning the unit, Peter should also have carried out a bump test to ensure that the sensors were responding as they should and that the filters had not been blocked or inhibited.

Upon arriving on site he should also have carried out another bump test on his gas monitor. This would have highlighted the following:

  • The unit was not functioning correctly, indicating potentially blocked filters, poisoned or inhibited sensors or even a faulty sensor. The bump test would also have enabled him to check that the audible and visual alarms were working and that the sensors’ response times met their required T90* response time
  • Peter would have then replaced his non-compliant unit with a functioning one, which would have safely detected and warned him about the H2S gas release which caused him injury.

So, what are the requirements of the ‘ideal’ bump tester? Crowcon has done extensive market research among users and fleet managers around the globe and found the following features to be essential:

  • Daily bump test reminder on gas detector
  • Zero maintenance
  • Self-test function
  • Minimal training
  • Real-time gas reading or life remaining
  • Hibernate mode
  • Ability to store test results
  • Ability to reconfigure alarm levels
  • Assign units to end-users

With this feedback in mind, the company went back to the drawing board and result is the Crowcon Clip range integrated with its C-Test bump test station. With all the above features, the C-Test makes bump testing quick and easy and ensures all employees are safe and compliant at all times.

* T90 = the time it takes for the sensor to read 90% of the test gas concentration.

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CO2 Gas Hazards in the Brewing Industry

The hazards associated with CO2 in the brewing industry are well known, yet people still die needlessly every year in tragic and completely avoidable accidents in breweries. Just last year in Germany, which has a good safety record, two workers died in separate incidents at the same brewery.

CO2 Gas Hazards in Breweries

CO2 Gas Hazards in Breweries

In the first incident, the owner was found dead with his head and torso in a beer mixing tank. It is thought that, after bottling and subsequent cleaning, the owner had leaned in to check the container and was overcome by CO2. 10 months later in the same brewery a worker was found dead in a pressure tank used to recirculate wheat beer. He had probably forgotten to fit a yeast plug and had leaned into the tank – which was already pressurised with CO2 – to fit one. He was found up to his hips in the container and had been poisoned – probably in seconds – due to the high concentration of CO2.

Both these accidents demonstrate the extremely hazardous nature of CO2 and how quickly one can be overcome by its deadly properties.

Properties and effects of CO2
CO2 is extremely hazardous and can kill in two ways: either by displacing O2, leading to rapid asphyxiation, or as a toxin in its own right. Exposure to as little 0.5% volume CO2 represents a toxic health hazard, while concentrations greater than 10% volume can lead to death. Because CO2 is completely odourless and colourless there is no physical indication of danger until it is usually too late.

CO2 is a by-product of the fermentation process and, because the gas is heavier than air, it collects at the bottom of containers and confined spaces such as tanks and cellars and can even spill out of fermenting tanks and sink to the brewery floor, where it forms deadly, invisible pockets. In fact, CO2 is a hazard throughout the brewing process, right through to packaging and bottling.

Safety precautions
Fermentation tanks, beer mixing tanks, silos and other confined spaces in the brewing industry are easily accessible – it is rare for them to be fitted with safety interlocks. For this very reason rigorous safety systems should be in place and always adhered to. Employers must assess the risks these areas pose to their employees and endeavour to prevent them.  In most cases, both the assessment and the safe working system will require testing of the atmosphere with gas detection equipment.

As a rule, entry should not be routine and should only be carried out if absolutely necessary. However, if entry is necessary – for example for an inspection or to ensure cleaning has been carried out correctly – suitable safety procedures must be followed.

Firstly, CO2 from the space must be completely removed. This can be done by discharging all the fermentation and pressure gasses directly into the open air using a ring main system. If this is not possible due to the layout, the CO2 must be manually extracted and safely diverted.

Prior to entering a tank or other confined space, a ‘release measurement’ of CO2 must be taken using a suitable CO2 monitor. This is the only reliable method to check whether the CO2 concentration is actually at a safe level. The measurement must be taken by a qualified person, usually by lowering the monitor into the chamber and leaving it there for several minutes. It goes without saying that any monitoring device must be durable, reliable and regularly calibrated and tested.

Protecting the worker entering a confined space
Anyone entering a tank or other confined space must also be equipped with a suitable gas detector. If a certain CO2 concentration is exceeded the device will go into alarm mode with both audio and visual alarms.

Generally, at a CO2 volume of 0.5 % by volume, a pre-warning is set off; at 1 to 2 % by volume the main alarm is activated. With most devices other alarm thresholds can be selected with the aim of avoiding the alarm sounding too frequently and simultaneously ensuring the safety of the person working in the container.

CO2 gas detector types
Both portable and fixed CO2 detectors can be used for CO2 monitoring in breweries. Fixed systems typically comprise one or more detector “heads” connected to a separate control panel. If a detector reads a dangerous CO2 level, extractor fans are automatically triggered and sirens or visual beacons can also be activated to warn workers to vacate the area. This sort of installation is suited to larger spaces like cellars and plant rooms.

However, much confined space work in the brewing industry takes place in more restricted areas like fermentation tanks where fixed detectors cannot be installed. This means compact portable units are required. Ease of use, with one button operation, should be the norm when it comes to portable detectors. This means minimal training is required while increased safety is ensured. Combining one or more sensors with powerful audible and visual signals to warn when pre-set gas levels are reached, compact portable detectors are easily carried in a confined space, ensuring that pockets of high CO2 concentration are not missed.

Certain features should be expected in every portable CO2 detector. Clearly, life-saving tools for demanding environments must be as tough as possible, with reliable electronics housed in impact-resistant casings.  While the need to leave gas sensors exposed to the atmosphere means that no instrument can be fully sealed, a high degree of protection against dust and water ingress is essential. Toughness notwithstanding, a well-designed detector will also be light and compact enough to wear for an entire shift.

Finally, because of the difficulties of working in a cramped space, perhaps under poor lighting, instruments should be easy to use. No matter how advanced a detector’s internal architecture or data management options, personnel in the field should be faced with nothing more daunting than a clear display, simple, one-button operation and loud/bright alarms.

Conclusion
Not taking the risk of CO2 seriously has led to many unavoidable deaths. If all the safety procedures described above are observed, the risks of dealing with this colourless, odourless and tasteless gas can be significantly reduced.

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