Seasonal Gas Dangers

When it comes to gas safety there’s no off-season, although it is important to know that there is such a thing as seasonal gas safety. When temperatures rise and fall, or the rain falls in deluge, it can have unique impacts on your gas appliances. To help you get a better understanding on seasonal gas safety, here is everything you need to know about key challenges throughout the year.  

Gas safety on holiday 

When on holiday, the last thing on your mind is gas safety, however, it’s crucial that you keep yourself safe. Whether it’s a long summer holiday or a winter weekend getaway are you packing a carbon monoxide monitor in your suitcase? If not, you should be. Gas safety on holiday is just as important as it is at home, this is because when you’re on holiday you have less knowledge or control over the state of any gas appliances. 

Although, there isn’t much difference between gas safety in a caravan or gas safety on boats, gas safety when camping in a tent is different. Gas camping stoves, gas heaters (such as table and patio heaters), and even solid fuel BBQs can produce carbon monoxide (CO) thereby leading to possible poisoning. Therefore, if they are brought into a tent, a caravan or any other enclosed space, during or after use, they can emit harmful CO putting anyone around them in danger. 

It’s also important to remember that gas safety regulations in other countries may differ from those outside the UK. While you can’t be expected to know what’s legal and what’s not everywhere you go, you can keep you and others around you safe by following some simple tips. 

Tips for gas safety on holiday 

  • Ask if the gas appliances in your accommodation have been serviced and safety checked. 
  • Take an audible carbon monoxide alarm with you.
  • When you arrive, the appliances may not work in the same way as those you have at home. If no instructions are provided, then contact your holiday rep or accommodation owner for assistance if you’re unsure.
    • Be aware of the signs of unsafe gas appliances 
    • Black marks and stains around the appliance 
    • Lazy orange or yellow flames instead of crisp blue ones 
    • High levels of condensation in your accommodation
  • Never use gas cookers, stoves or BBQs for heating, and ensure they have adequate ventilation when in use.  

BBQ safety

Summer is a time for being outdoors and enjoying long evenings. Come rain or shine we light up our BBQs with usually the only worries being whether it will rain, or the sausages are fully cooked through. Gas safety isn’t just something for the home, or industrial environments, BBQs need special attention to ensure they’re safe.  

Carbon monoxide is a gas that its health risks are widely known with many of us installing detectors in our homes and businesses. However, the association of carbon monoxide is associated with our BBQs is unknown. If the weather is poor, we may decide to barbeque in the garage doorway or under a tent or canopy. Some of us may even bring our BBQs into the tent after use.  These can all be potentially fatal as the carbon monoxide collects in these confined areas. It must be noted that the cooking area should be well away from buildings and be well ventilated with fresh air, otherwise you are at risk of carbon monoxide poisoning. Knowing the signs of carbon monoxide poisoning is vital – Headaches, Nausea, Breathlessness, Dizziness, Collapse or Loss of consciousness. 

Equally with a propane or butane gas canister, we store in our garages, sheds and even our homes unaware that there is a risk of a potentially deadly combination of an enclosed space, a gas leak and a spark from an electrical device.  All of which could cause an explosion. 

Gas safety in winter

When the cold weather sets in, gas boilers and gas are fired up for the first time in several months, to keep us warm. However, this increased usage can put extra pressure on appliances and can result in them breaking down. Therefore, preparing for winter by ensuring gas appliances – including boilers, warm air heaters, cookers and fires – have been regularly safety checked and maintained by a qualified Gas Safe registered engineer, who carry gas detectors 

What to do if you suspect a gas leak

If you can smell gas or think there could be a gas leak in a property, boat or caravan, it’s important to act fast. A gas leak poses a risk of fire or even explosion. 

You should: 

  • Extinguish any naked flames to stop the chance of fire or explosion.
  • Turn off the gas at the meter if possible (and safe to do so).
  • Open windows to allow ventilation and ensure the gas dissipates.
  • Evacuate the area immediately to prevent risk to life.
  • Inform your holiday representative or accommodation owner immediately or equivalent.
  • Seek medical attention if you feel unwell or show signs of carbon monoxide poisoning.

Carbon monoxide poisoning symptoms

The signs and symptoms of carbon monoxide poisoning are often mistaken for other illnesses, such as food poisoning or flu. Symptoms include:

  • Headache
  • Dizziness
  • Breathlessness
  • Nausea or feeling sick
  • Collapse
  • Loss of consciousness

Anyone who suspects they are suffering from carbon monoxide poisoning should immediately go outside into the fresh air and seek urgent medical attention. 

Personal gas detectors 

The Clip SDG personal gas detector is designed to withstand the harshest industrial working conditions and delivers industry leading alarm time, changeable alarm levels and event logging as well as user-friendly bump test and calibration solutions. 

Gasman with specialist CO sensor is a rugged, compact single gas detector, designed for use in the toughest environments. Its compact and lightweight design makes it the ideal choice for industrial gas detection. 

Connected safety – Fleet Health Monitoring for Multi-Site Fleets 

As you are no doubt aware, most gas detectors require periodic maintenance and testing, if their owners are to comply with gas safety regulations and keep their workforce safe. As you are also no doubt aware, some organisations have large numbers of gas detectors (often referred to as a fleet or fleets of devices) and keeping track of the maintenance requirements for each and every one of these can be a major headache. If the business operates from multiple sites, and especially if gas monitors move between those sites, this problem is greatly magnified. 

What is Fleet Health Monitoring? 

Many companies still manage their device fleets manually, using spreadsheets to track the location, status and calibration schedule of each detector. This is repetitive and often tedious work that takes staff away from more productive tasks. Manual management is also, frankly, inefficient. It may just about suffice for basic elements like tracking which device is where (although even that becomes cumbersome when very large numbers are involved). But when managers also need to know which devices are out of battery so cannot be used on the next shift, and which ones are showing signs of wear and tear (and they should know these things) then the data becomes too overwhelming for manual methods to handle. 

In these circumstances, it is all too easy for devices to go missing or for somebody to arrive on shift and find that the detector allocated to them is out of battery. The good news is that now, connected safety initiatives such as cloud software applications can remove these problems entirely and make fleet device management much more straightforward and efficient, even across multiple sites. 

How does it work and what are the requirements? 

Cloud software applications for gas detector fleets, such as Crowcon Connect, automatically transfer and process the gas data from gas detectors, and store it securely in the cloud in useful formats. This data includes not just exposure information, readings and times, but also more detailed information about the way in which devices are used (i.e., the extent of compliance with regulations) and who was using the device at each point (it is very easy to associate a specific user with a specific device in Crowcon Connect, for example, even if that device is part of a fleet or pool).  

Crowcon Connect can also be tailored to suit the specific requirements of a business or site, and authorised users can access the dashboard from any location, at any time. All you need is a connected device (including mobile devices; many people use their smartphones or tablets). Access can also be restricted by fleet or team, to maintain privacy where required. 

What are the benefits? 

Crowcon Connect has a user-friendly dashboard that displays user information, alarm and exposure data, device locations, dates when calibration/maintenance is due, user information and a host of other data, all in an easy-to-use format. It gives managers a panoramic view of the entire fleet, regardless of where each devices is located or has been used, and that information can be used to make safety, compliance and productivity gains and identify areas for improvement.  

This type of cloud software can also drive up safety standards, because now managers can see at a glance which devices are out of battery and cannot be used in the next shift, and/or which require maintenance. That maintenance and calibration can also be planned in ways that minimise downtime, because the dashboard lets users see the relevant dates in advance. 

What is more, because the data is collected automatically, the risk of human error is eliminated and Crowcon Connect can deliver trustworthy, complete documents that are ready for use in any compliance or safety audit.  

Want to find out more? Click here to read more about Crowcon’s own cloud software solution. 

 

Why Do I Need a Personal Carbon Monoxide Monitor?

What is Carbon Monoxide?

Carbon monoxide (CO) is a colourless, odourless, tasteless, poisonous gas produced by incomplete burning of carbon-based fuels, including gas, oil, wood, and coal. It is only when fuel does not burn fully that excess CO is produced, which is poisonous. When the excess CO enters the body, it stops the blood from bringing oxygen to cells, tissues, and organs. CO is poisonous as you cannot see it, taste it or smell it but CO can kill quickly without warning. The Health and Safety Executive (HSE) statistics show every year around 15 people die from CO poisoning caused by gas appliances and flues that have not been correctly installed, maintained or those that are poorly ventilated. Although some levels that present do not kill but can cause serious harm to health if breathed in over a prolonged period. with extreme cases causing paralysis and brain damage because of prolonged exposure to CO. Therefore, understanding the danger of CO poisoning as well as educating the public to take appropriate precautions could inevitably reduce this risk.  

Where is CO present and why is it dangerous?

CO is present in several different industries, such as manufacturing, electricity supply, coal and metal mining, food manufacturing, oil and gas, production of chemicals and petroleum refining to name a few.  

The effects of CO poisoning, can include breathlessness, chest pain, seizures and loss of consciousness which may lead to death as well as physical problems that can occur, depending on how much CO is in the air. For example: 

CO volume (parts per million (ppm)  Physical Effects 
200 ppm  Headache in 2–3 hours 
400 ppm  Headache and nausea in 1–2 hours, life threatening within 3 hours. 
800 ppm  Can cause seizures, severe headaches and vomiting in under an hour, unconsciousness within 2 hours. 
1,500 ppm  Can cause dizziness, nausea, and unconsciousness in under 20 minutes; death within 1 hour 
6,400 ppm  Can cause unconsciousness after two to three breaths: death within 15 minutes 

 Around 10 to 15% of people who obtain serve CO poisoning go on to develop long-term complications. These include brain damage, vision and hearing loss, Parkinson’s disease, and coronary heart disease.  

How does a CO Monitor help with safety and compliance and if so, what products are available?

Any operators who are working on commercial installations or domestic application in a home are required to be registered with a relevant association, i.e., Gas safe register, Heating equipment testing and approval scheme (HETAS) – solid fuel applications and Oil firing technical association (OFTEC) – oil appliances. Therefore, personal CO monitors offer the highest quality and portability CO gas detection to protect the operator at work. 

Crowcon Clip SGD is designed for use in hazardous areas whilst offering reliable and durable fixed life span monitoring in a compact, lightweight and maintenance free device. Clip SGD has a 2-year life and is available for hydrogen sulphide (H2S), carbon monoxide (CO) or oxygen (O2). The Clip SDG personal gas detector is designed to withstand the harshest industrial working conditions and delivers industry leading alarm time, changeable alarm levels and event logging as well as user-friendly bump test and calibration solutions. 

Crowcon Gasman with specialist CO sensor is a rugged, compact single gas detector, designed for use in the toughest environments. Its compact and lightweight design makes it the ideal choice for industrial gas detection. Weighing just 130g, it is extremely durable, with high impact resistance and dust/water ingress protection, loud 95 dB alarms, a vivid red/ blue visual warning, single-button control and an easy-to-read, backlit LCD display to ensure clear viewing of gas level readings, alarm conditions and battery life. Data and event logging are available as standard, and there is a built-in 30-day advance warning when calibration is due. 

What’s the difference between a pellistor and an IR sensor?

Sensors play a key role when it comes to monitoring flammable gases and vapours. Environment, response time and temperature range are just some of the things to consider when deciding which technology is best.

In this blog, we’re highlighting the differences between pellistor (catalytic) sensors and infrared (IR) sensors, why there are pros and cons to both technologies, and how to know which is best to suit different environments.

Pellistor sensor

A pellistor gas sensor is a device used to detect combustible gases or vapours that fall within the explosive range to warn of rising gas levels. The sensor is a coil of platinum wire with a catalyst inserted inside to form a small active bead which lowers the temperature at which gas ignites around it. When a combustible gas is present the temperature and resistance of the bead increases in relation to the resistance of the inert reference bead. The difference in resistance can be measured, allowing measurement of gas present. Because of the catalysts and beads, a pellistor sensor is also known as a catalytic or catalytic bead sensor.

Originally created in the 1960’s by British scientist and inventor, Alan Baker, pellistor sensors were initially designed as a solution to the long-running flame safety lamp and canary techniques. More recently, the devices are used in industrial and underground applications such as mines or tunnelling, oil refineries and oil rigs.

Pellistor sensors are relatively lower in cost due to differences in the level of technology in comparison to IR sensors, however they may be required to be replaced more frequently.

With a linear output corresponding to the gas concentration, correction factors can be used to calculate the approximate response of pellistors to other flammable gases, which can make pellistors a good choice when there are multiple flammable vapours present.

Not only this but pellistors within fixed detectors with mV bridge outputs such as the Xgard type 3 are highly suited to areas that are hard to reach as calibration adjustments can take place at the local control panel.

On the other hand, pellistors struggle in environments where there is low or little oxygen, as the combustion process by which they work, requires oxygen. For this reason, confined space instruments which contain catalytic pellistor type LEL sensors often include a sensor for measuring oxygen.

In environments where compounds contain silicon, lead, sulphur and phosphates the sensor is susceptible to poisoning (irreversible loss of sensitivity) or inhibition (reversible loss of sensitivity), which can be a hazard to people in the workplace.

If exposed to high gas concentrations, pellistor sensors can be damaged. In such situations, pellistors do not ‘fail safe’, meaning no notification is given when an instrument fault is detected. Any fault can only be identified through bump testing prior to each use to ensure that performance is not being degraded.

 

IR sensor

Infrared sensor technology is based on the principle that Infrared (IR) light of a particular wavelength will be absorbed by the target gas. Typically there are two emitters within a sensor generating beams of IR light: a measurement beam with a wavelength that will be absorbed by the target gas, and a reference beam which will not be absorbed. Each beam is of equal intensity and is deflected by a mirror inside the sensor onto a photo-receiver. The resulting difference in intensity, between the reference and measurement beam, in the presence of the target gas is used to measure the concentration of gas present.

In many cases, infrared (IR) sensor technology can have a number of advantages over pellistors or be more reliable in areas where pellistor-based sensor performance can be impaired- including low oxygen and inert environments. Just the beam of infrared interacts with the surrounding gas molecules, giving the sensor the advantage of not facing the threat of poisoning or inhibition.

IR technology provides fail-safe testing. This means that if the infrared beam was to fail, the user would be notified of this fault.

Gas-Pro TK uses a dual IR sensor – the best technology for the specialist environments where standard gas detectors just won’t work, whether tank purging or gas freeing.

An example of one of our IR based detectors is the Crowcon Gas-Pro IR, ideal for the oil and gas industry, with the availability to detect methane, pentane or propane in potentially explosive, low oxygen environments where pellistor sensors may struggle. We also use a dual range %LEL and %Volume sensor in our Gas-Pro TK, which is suitable for measuring and switching between both measurements so it’s always safely operating to the correct parameter.

However, IR sensors aren’t all perfect as they only have a linear output to target gas; the response of an IR sensor to other flammable vapours then the target gas will be non-linear.

Like pellistors are susceptible to poisoning, IR sensors are susceptible to severe mechanical and thermal shock and also strongly affected by gross pressure changes. Additionally, infrared sensors cannot be used to detect Hydrogen gas, therefore we suggest using pellistors or electromechanical sensors in this circumstance.

The prime objective for safety is to select the best detection technology to minimise hazards in the workplace. We hope that by clearly identifying the differences between these two sensors we can raise awareness on how various industrial and hazardous environments can remain safe.

For further guidance on pellistor and IR sensors, you can download our whitepaper which includes illustrations and diagrams to help determine the best technology for your application.

You won’t find Crowcon sensors sleeping on the job

MOS (metal oxide semiconductor) sensors have been seen as one of the most recent solutions for tackling detection of hydrogen sulphide (H2S) in fluctuating temperatures from up to 50°C down to the mid-twenties, as well as humid climates such as the Middle East.

However, users and gas detection professionals have realised MOS sensors are not the most reliable detection technology. This blog covers why this technology can prove difficult to maintain and what issues users can face.

One of the major drawbacks of the technology is the liability of the sensor “going to sleep” when it doesn’t encounter gas for a period of time. Of course, this is a huge safety risk for workers in the area… no-one wants to face a gas detector that ultimately doesn’t detect gas.

MOS sensors require a heater to equalise, enabling them to produce a consistent reading. However, when initially switched on, the heater takes time to warm up, causing a significant delay between turning on the sensors and it responding to hazardous gas. MOS manufacturers therefore recommend users to allow the sensor to equilibrate for 24-48 hours before calibration. Some users may find this a hinderance for production, as well as extended time for servicing and maintenance.

The heater delay isn’t the only problem. It uses a lot of power which poses an additional issue of dramatic changes of temperature in the DC power cable, causing changes in voltage as the detector head and inaccuracies in gas level reading. 

As its metal oxide semiconductor name suggests, the sensors are based around semiconductors which are recognised to drift with changes in humidity- something that is not ideal for the humid Middle Eastern climate. In other industries, semiconductors are often encased in epoxy resin to avoid this, however in a gas sensor this coating would the gas detection mechanism as the gas couldn’t reach the semiconductor. The device is also open to the acidic environment created by the local sand in the Middle East, effecting conductivity and accuracy of gas read-out.

Another significant safety implication of a MOS sensor is that with output at near-zero levels of H2S can be false alarms. Often the sensor is used with a level of “zero suppression” at the control panel. This means that the control panel may show a zero read-out for some time after levels of H2S have begun to rise. This late registering of low-level gas presence can then delay the warning of a serious gas leak, opportunity for evacuation and the extreme risk of lives.

MOS sensors excel in reacting quickly to H2S, therefore the need for a sinter counteracts this benefit. Due to H2S being a “sticky” gas, it is able to be adsorbed onto surfaces including those of sinters, in result slowing down the rate at which gas reaches the detection surface.

To tackle the drawbacks of MOS sensors, we’ve revisited and improved on the electrochemical technology with our new High Temperature (HT) H2S sensor for XgardIQ. The new developments of our sensor allow operation of up to 70°C at 0-95%rh- a significant difference against other manufacturers claiming detection of up to 60°C, especially under the harsh Middle Eastern environments.

Our new HT H2S sensor has been proven to be a reliable and resilient solution for the detection of H2S at high temperatures- a solution that doesn’t fall asleep on the job!

Click here for more information on our new High Temperature (HT) H2S sensor for XgardIQ.

Have you ever thought about the dangers behind your favourite beverage?

Beer Production

It’s only natural for us to associate the need for gas detection in the oil and gas, and steel industries, but have you thought about the need to detect hazardous gases such as carbon dioxide and nitrogen in the brewing and beverage industry?

Maybe it’s because nitrogen (N2) and carbon dioxide (CO2) are naturally present in the atmosphere. It could be that CO2 is still under-valued as a hazardous gas. Although in the atmosphere CO2 remains at very low concentrations – around 400 parts per million (ppm), greater care is needed in brewery and cellar environments where in confined spaces, the risk of gas canisters or associated equipment leaking could lead to elevated levels. As little as 0.5% volume (5000ppm) of CO2 is a toxic health hazard. Nitrogen on the other hand, can displace oxygen.

CO2 is colourless, odourless and has a density which is heavier than air, meaning pockets of CO2 gather low on the ground gradually increasing in size. CO2 is generated in huge amounts during fermentation and can pose a risk in confined spaces such as vats, cellars or cylinder storage areas, this can be fatal to workers in the surrounding environment, therefore Health & Safety managers must ensure the correct equipment and detectors are in place.

Brewers often use nitrogen in multiple phases of the brewing and dispensing process to put bubbles into beer, particularly stouts, pale ales and porters, it also ensures the beer doesn’t oxidise or pollute the next batch with harsh flavours. Nitrogen helps push the liquid from one tank to another, as well as offer the potential to be injected into kegs or barrels, pressurising them ready for storage and shipment. This gas is not toxic, but does displace oxygen in the atmosphere, which can be a danger if there is a gas leak which is why accurate gas detection is critical.

Gas detection can be provided in the form of both fixed and portable. Installation of a fixed gas detector can benefit a larger space such as plant rooms to provide continuous area and staff protection 24 hours a day. However, for worker safety in and around cylinder storage area and in spaces designated as a confined space, a portable detector can be more suited. This is especially true for pubs and beverage dispensing outlets for the safety of workers and those who are unfamiliar in the environment such as delivery drivers, sales teams or equipment technicians. The portable unit can easily be clipped to belts or clothing and will detect pockets of CO2 using alarms and visual signals, indicating that the user should immediately vacate the area.

At Crowcon, we’re dedicated in growing a safer, cleaner, healthier future for everyone, every day by providing best in class gas safety solutions. It’s vital that once gas detectors are deployed, employees should not get complacent, and should be making the necessary checks an essential part of each working day as early detection can be the difference between life and death.

Quick facts and tips about gas detection in breweries:

  • Nitrogen and CO2 are both colourless and odourless. CO2 being 5 times heavier than air, making it a silent and deadly gas.
  • Anyone entering a tank or other confined space must be equipped with a suitable gas detector.
  • Early detection can be the difference between life and death.

Once again, Gas-Pro is ‘detector of choice’ for volcano environmental expedition

We are all familiar with the term global warming and often see statistics about the potential effects this could have on our planet.  One such prediction is by the end of this century the globe will increase in temperature by between 0.8 and 4 degrees.

What many of us may not know is that volcanoes, which are a completely natural phenomenon, contribute a significant amount of gases into our atmosphere. And these gases are currently not considered in the world’s climate models, which means there is potentially a large margin of error.

However, this could be about to change as Yves Moussallam, an inspiring French Volcanologist, who with the support of Rolex and the 2019 Rolex Awards for Enterprise, has made it his mission to understand volcanos and how they impact on our planet.  He ventures into these dramatic and dangerous environments to take measurements which are used by scientists and climatologists to improve their prediction models.

By observing volcanos, and gathering this vitally important data, he is helping the world understand the impact volcanos are having on climate change.

Yves is no stranger to volcanic expeditions. In 2015, he led a small team to the Nazca subduction zone in South America. Their mission was to provide the first accurate and large-scale estimate of the flux of several volatile gas species.

To keep the team safe, Yves selected Crowcon detection equipment and was delighted with Gas man and Gas-Pro’s lightweight, clean and safe functionality.

Now Yves is back with a new expedition and has turned to Crowcon once again. This time, Yves is heading to the region of Melanesia in Italy.  Satellites, which are used to track volcanic behaviour, have shown that this region is responsible for approximately a third of global volcanic gas emissions.

His expedition will climb these volcanoes and take measurements directly in the volcanic plume.

There are two main methods to measure gases in volcanoes.  The first is via satellite which takes images from space.  The second is to go directly into the field and measure gas released at its source.

Experts believe the method of working directly in the field is the most accurate as it is positioned far closer to the source so there is a reduced risk of error.

To conduct these measurements requires tried, tested and trusted equipment and with Crowcon’s proven track record, Yves turned again to Gas-Pro.

Crowcon’s Gas-Pro includes an onboard datalogging feature which will provide an extra line of data and an idea of average exposure, which is important for expeditions that span longer periods.  It is also lightweight which is hugely beneficial when carrying bulky equipment.

Everyone at Crowcon wishes Yves a safe and successful expedition and we hope the data he gathers will help us understand the impact volcanos have on our world.

#Rolex #RolexAwards #PerpetualPlanet #Perpetual

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. 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.

Regular maintenance of gas distribution systems is 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.

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 devices 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.

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.

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.

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.

 

Explosion hazards in inerted tanks and how to avoid them

Hydrogen sulphide (H2S) is known for being extremely toxic, as well as highly corrosive. In an inerted tank environment, it poses an additional and serious hazard combustion which, it is suspected, has been the cause of serious explosions in the past.

Hydrogen sulphide can be present in %vol levels in “sour” oil or gas. Fuel can also be turned ‘sour’ by the action of sulphate-reducing bacteria found in sea water, often present in cargo holds of tankers. It is therefore important to continue to monitor the level of H2S, as it can change, particularly at sea. This H2S can increase the likelihood of a fire if the situation is not properly managed.

Tanks are generally lined with iron (sometimes zinc-coated). Iron rusts, creating iron oxide (FeO). In an inerted headspace of a tank, iron oxide can react with H2S to form iron sulphide (FeS). Iron sulphide is a pyrophore; which means that it can spontaneously ignite in the presence of oxygen

Excluding the elements of fire

A tank full of oil or gas is an obvious fire hazard under the right circumstances. The three elements of fire are fuel, oxygen and an ignition source. Without these three things, a fire can’t start. Air is around 21% oxygen. Therefore, a common means to control the risk of a fire in a tank is to remove as much air as possible by flushing the air out of the tank with an inert gas, such as nitrogen or carbon dioxide. During tank unloading, care is taken that fuel is replaced with inert gas rather than air. This removes the oxygen and prevents fire starting.

By definition, there is not enough oxygen in an inerted environment for a fire to start. But at some point, air will have to be let into the tank – for maintenance staff to safety enter, for example. There is now the chance for the three elements of fire coming together. How is it to be controlled?

  • Oxygen has to be allowed in
  • There may be present FeS, which the oxygen will cause to spark
  • The element that can be controlled is fuel.

If all the fuel has been removed and the combination of air and FeS causes a spark, it can’t do any harm.

Monitoring the elements

From the above, it is obvious how important it is to keep track of all the elements that could cause a fire in these fuel tanks. Oxygen and fuel can be directly monitored using an appropriate gas detector, like Gas-Pro TK. Designed for these specialist environments, Gas-Pro TK automatically copes with measuring a tank full of gas (measured in %vol) and a tank nearly empty of gas (measured in %LEL). Gas-Pro TK can tell you when oxygen levels are low enough to be safe to load fuel or high enough for staff to safely enter the tank. Another important use for Gas-Pro TK is to monitor for H2S, to allow you judge the likely presence of the pryophore, iron sulphide.

Servicing for safety… A visit to the oil refinery

Working in the office makes it easy to focus on the individual tasks and get detached from how our products are making a difference to people’s lives. One of our customers was kind enough to facilitate an onsite visit so that Andrea (our Halma Future Leader on a marketing placement) could see first-hand how our products are used and who the end users are. This meant a visit to an oil refinery to see where our Crowcon portable gas detectors are used.


“The main thing that surprised me was the sheer size of the site. The oil refinery was very spaced out and it took us 10 minutes to walk from the entrance of the site to where the Crowcon engineer’s based. The engineers and employees around different parts of the refinery wore Hi Vis jackets, big safety boots, hard hats and all appeared to have personal gas detectors. During a quick site tour, I learned the products of the oil refinery are not limited to gas or petrol, but also tar, asphalt, lubricants, washing up liquid, paraffin wax and much more.

The products are all stored in big containers with pipes all over the site. Most of the products are highly flammable which explains the big focus on safety. In the distance, there were a few dome shaped containers which are pressurised vessels. If one of them were to explode, it would have a 10 mile blast radius. Suddenly I had the urge to leave and drive about 10 miles.

Crowcon’s engineer base was full of orange T4s, Gas-Pros as well as an army of “Daleks”, I mean Detectives, awaiting calibration and service. While the harshness of this industrial environment was evident from their appearance, they were otherwise in good working order, and the service engineer worked through the devices quickly.

The end users think of them as a simple device they have to wear to do their job, and they like the simplicity and reliability of Crowcon devices. The Detectives get thrown around and Gas-Pros are almost black is comparison to the usual orange, which just showcases how important the robustness of our devices is. The dangers of this working environment are not generally a big concern to the users, this is everyday life to them. Our devices help ensure they go home after a tough shift. Ensuring the devices are functioning properly is down to the service engineers, and they need to think for the users to ensure that the devices are being used properly.

Seeing Crowcon’s devices being used and the number of times someone enquired if the devices are calibrated and ready to go back into action, highlighted just how important use of portables as part of the safety regime  is considered. “Quality” and “robust” is how users describe Crowcon products and even though they may now treat them like the life saving devices they are, the devices are regularly used and valued. They make a very flammable and dangerous environment a safer place to be.”