During the past 60 years, the use of the natural gas combined cycle (NGCC) process for electricity generation has grown to make it one of the world’s leading sources of power. Along the way, natural gas combined cycle efficiency has improved because of engineering advancement.
This blog offers an overview of NGCC. It includes a brief look at its history, covers the advantages of NGCC over other power generation types, and discusses some of the challenges engineers still are confronting as the technology moves to the future.
Read part 1 of our white paper- 2021 Power Generation and Renewable Energy Trends, to learn how fossil-based power generation technologies are rapidly evolving and renewable technologies are being scaled to meet the demands of the 21st-century market.
The history of natural gas turbines to generate electric power starts in 1940. In that year, a plant in Switzerland came online and produced 4 MW of power by passing superheated gas through a turbine; a process now known as a “simple cycle.” This was the first time a natural gas turbine had been used to supply the public with electricity. Larger plants were built in the decades that followed. In 1960, a simple cycle plant in British Columbia, Canada became the first to generate 100 MW of electricity.
A year later, a newer gas technology arrived: Natural Gas Combined Cycle (NGCC). The world’s first combined-cycle power plant, a 75 MW facility in Austria, started operation in 1961. By the time of its retirement in 1974, and thanks to combined cycle efficiency improvements, NGCC had established itself as “the most efficient and low-cost route to electricity production,” according to an article in International Turbomachinery. Today, NGCC is one of the leading natural gas power technologies in the world.
How NGCC works
To understand how NGCC works, it’s helpful to understand the ways it’s different from simple cycle technology.
In a simple cycle gas turbine plant, hot gas is burned and propelled at high pressure through a single turbine. The turning of the turbine is used to generate electricity. Wasted heat is simply lost in this design, and the overall efficiency of such a plant is approximately 35 to 40 percent.
An NGCC plant improves on this design, leveraging that waste heat and an additional generator cycle to maximize overall plant efficiency.
In the first cycle of an NGCC plant, natural gas is burned to directly power a generator that produces electricity. The hot exhaust that would otherwise be lost in a simple cycle plant is instead captured for a second cycle. That heat energy is delivered to a boiler and used to generate steam from water. This, in turn, is used to power a steam turbine generator that produces additional electricity. The steam then condenses back into liquid water and is recycled for further use. With these multiple cycles, overall efficiency is boosted to around 50 to 60 percent. Today’s NGCC plants range in size, with the largest producing more than 1,500 MW.
Improvements to natural gas combined cycle efficiency
NGCC technology has evolved over the years, and plants have been built with increasing capacities. Global and U.S. capacity for gas-fired electricity has continued to grow steadily in recent decades. Natural gas plants (all types) now supply more than half of the energy for both residential and commercial use, and 41% of the energy used by U.S. industries. And as consumers and industries alike become more aware of the broader impact of their energy use, they can rest easier knowing that natural gas plants produce significantly fewer emissions than the average coal-fired plant.
An article in the journal Science Direct lays out several key advantages for NGCC technology.
Boosted electrical efficiency. NGCC plants have an efficiency of between 50 to 60% of fuel used. This is the highest efficiency currently available among power plant generating technologies; it compares to an efficiency of 30 to 35% for a coal-fired plant. A large, simple cycle, natural gas plant has an efficiency of 35 to 40%, according to Bridgestone Associates.
Lower capital costs. The capital cost of an NGCC plant larger than 200 MW ranges from $450 to $650 per kW. A smaller plant ranges from $650 to $1,200 per kW. Additionally, a large NGCC plant can be built in less than 24 months.
Lower emissions and environmental impact. NGCC plants have the lowest emissions of unburnt hydrocarbons, nitrogen oxides, and carbon monoxide of any current thermal power plant technology. NGCC plants also have a more compact footprint than other major power plant types, further lessening their impact on the environment.
The highest recorded efficiency for an NGCC plant is 63.08%. This was achieved at the 1,190 MW Chubu Electric Nishi Nagoya plant in Japan, according to a 2018 article in POWER magazine.
According to another analysis, prepared in 2019 by the consulting firm Sargent & Lundy for the U.S. Energy Information Administration, a 1,100 MW NGCC plant would have an estimated capital cost of $958 per kW. A 240 MW simple cycle gas plant would have a total capital cost of $713 per kW. A 650 MW coal-fired plant without carbon capture, meanwhile, would have an estimated total capital cost of $3,676 per kW. Adding incremental levels of carbon capture technology to the coal-fired plant would increase this cost correspondingly.
The Science Direct article also predicts that:
These (NGCC) plants will displace coal in the power generation sector by 2050, under a model scenario where industrialized nations reduce CO2 emissions by 2050 through carbon emission pricing. Large emerging economies such as Brazil, China, and India will reduce CO2 emissions by 2070.
The annual energy outlook for NGCC in the US
According to the U.S. Energy Information Administration, NGCC first surpassed coal-fired plants for producing electricity in late 2015 and early 2016 when natural gas prices were very low. This trend reversed itself when gas prices rose, until February 2018. As of 2020, NGCC is responsible for 26% of electricity generation in the U.S., making it the clear leader. With the growing number of NGCC plants and the retirement of more coal-fired plants, the technology should be the leading source of power in the U.S. for the foreseeable future.
Managing NGCC operations and maintenance costs
Compared to other types of power generation, operations and maintenance costs for NGCC plants are relatively low. Data from the International Energy Agency show that NGCC has an average O&M cost of $25 per kW. This matches solar photovoltaic ($25 per kW), and beats coal ($43 per kW), onshore wind ($46 per kW), hydropower ($53 per kW), and nuclear ($198 per kW).
Nevertheless, plant operators are smart to take a planful approach to maintenance, especially for NGCC plants used in applications with frequent starts and stops.
Rely on Parker Hannifin for NGCC plant maintenance needs
Parker Hannifin offers a wide range of solutions for power plants. These include products for automation, filtration, fluid connections, hydraulics, instrumentation, and sealing. One utility company managing a 790 MW NGCC plant was able to increase the life of its electrohydraulic service valves from 3,100 hours to more than 60,000 hours, simply by switching to Parker's solution.
To learn more about advancements in power generation, read our Power Generation and Renewable Energy Trends White Paper – Part 1.
This article was contributed by the Process Control Team.
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In onshore and offshore oil and gas, operators' demand for components that satisfy a reduction in leakage paths resulted in our designing the Monoflange valve, combining primary and secondary valves into one compact unit. Integrating piping and instrument valves into a single unit delivers cost and safety benefits to the oil and gas, petrochemical, and chemical markets.
The Monoflange has a needle valve primary and secondary rather than ball valves. The result is a lower system mass, which reduces loading and vibration stresses, further improving safety and reliability. Being smaller than a traditional double block and bleed valve, gives even more space and weight advantages. This ensures that the Monoflange valve is a cost-efficient option for both owners and operators.
How to safely replace a plugged Monoflange with uninterrupted production
Let's take a look step-by-step at how to safely remove a plugged Monoflange using our integrated Monoball solution to enable the processing pipeline to continue operation. For this example, the application is using a close-coupled Monoflange with an integrated Monoball. This enables the process pipeline and service to continue while the Monoflange is being serviced or replaced. This unique product combination allows the process to continue with no loss of production, increasing uptime.
Step 1 - To ensure the safe removal of the Monoflange valve, we will isolate the Monoball valve by turning the handle 90 degrees - this will prevent any process media from escaping to the atmosphere while the Monoflange is absent.
Step 2 - To ensure all media is vented, open both the Monoflange block valves ( Primary and Secondary) and finally turn the vent on the Monoflange anticlockwise. This will remove the trapped volume of liquid or gas between the process and the instrument in a controlled manner. For substances such as H2S, an integral tube fitting and tube can be used to ensure safe removal.
Step 3 - Close the isolation vent on the Monoflange, two clockwise rotations. This will return the product to normal service-ready conditions.
Step 4 - Remove the four top nuts and washers with a spanner/wrench. This will allow the operator to remove the Monoflange and transmitter from the Monoball for transfer to the service workshop to clean or replace the Monoflange.
Step 5 - In the service workshop, the maintenance team will remove the transmitter and either clean or replace the Monoflange.
Step 6 - Return the Monoflange and transmitter to the Monoball.
Step 7 - Retighten nuts with spanner/wrench.
Step 8 - Open the Monoball valve to return to normal working conditions.
Watch this video and see all the steps to safely removing a plugged Monoflange valve by using a closed coupled Monoball valve arrangement.
This helpful support content was contributed by the Instrumentation Products Division, Parker Hannifin
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Small and mid-scale LNG plants are dramatically changing the application sphere for natural gas as an alternative fuel for transportation, both onland and for marine shipping use. They are helping drive adoption in various high horsepower applications and making gas capture and distribution from remote areas and wells without pipelines a reality.LNG plant requirements drive need for smaller line and fittings
As the requirement for small and mid-scale LNG plants grows, so does the need for tube connection technology for smaller line sizes. In the past, connection technology was limited to either orbital welding or double ferrule compression fittings. Today, driven by cryogenic applications, there are four connection options in the less than two-inch space: instrumentation compression double ferrule fittings; instrumentation compression single ferrule fittings; O-ring face seal fittings; and permanent fittings.
Connection in a cryogenic application should focus on five critical areas:
Safety is critical in small and mid-scale LNG plants. In these complex plants, electricity, gas and water will often coexist in close proximity. Add cryogenic temperatures to the mix and the environment becomes extreme.
The most important rule of safety in an LNG plant is to keep the media contained. Good tube connections prevent catastrophic failure at connection points. A failure mode and effect analysis reveal the threat that a bad connection – or a poorly made one – can pose to a plant. In addition to explosion leaks, the danger of frostbite exists with cryogenic temperatures. A good connection is a first defense in preventing exposure and harm to personnel.Leakage and fugitive emissions
Leakage of methane, a greenhouse gas -- while still not regulated -- is a major concern in LNG plants. Overall, fugitive emissions will become increasingly important; keeping hundreds and thousands of connections in an LNG plant from leaking will be key.
As a basic requirement, ensure bubble-tight connections that follow appropriate leak specifications to future-proof against fugitive emissions while not limiting solely to safe exposure levels. Apart from methane leaks, cryogenic fluid leaks can cause frostbite and major freezing hazards. A small, seemingly safe leak is also a loss of revenue and efficiency. Leak-tight connections can add up to savings and notable percentage points of efficiency.Ease of assembly
A big challenge for small-scale, modular LNG plants is the flexibility to connect on-site to a dispensing system or a point-of-use system. This often means a lot of field connections and the capability to carry out repairs. Other times it means making certain connections at the time of installation. While welding sometimes seems to be the most straightforward strategy for a permanent joint, finding certified and trained welders may not be simple or easy.Longevity
With the operational life of an LNG plant in the range of 15 to 25 years or more, it is critical to select corrosion-resistant, robust and reliable connection technologies that outlast the moving parts. Longevity can be achieved by choosing materials that resist corrosion from environmental sources and that are compatible with the media or fluid being transported.Code compliance
Finally, it is essential to consider applicable codes of construction that, in some environments, may include marine standards such as those for ABS or DNV GL. Code compliance helps ensure that all the above topics are covered. Codes to consider include:
The end-use must take into account all possible interface points such as vehicles, tankers, vessels or rail cars to define application standards.Connection technology challenges and advantages
In both single and double ferrule fittings, stainless steel parts that rub together under high pressure have a strong tendency to cold weld and seize, leaking to leaks and the resulting fugitive emissions.
Using fittings coated with molybdenum disulfide can avoid this problem. Solid molybdenum disulfide readily adheres to surfaces, is noted for its lubrication and anti-seizing properties, and does not squeeze out under extreme pressure. The result is low assembly torque and consistent, leak-free performance, even with repeated remakes.
Many fittings manufacturers also combat fitting leaks – and the resulting possibility of fugitive emissions – through proprietary ferrule-hardening processes designed to heighten corrosion resistance. For example, Parker treats its ASTM 316 stainless steel, single and double ferrule fittings with Suparcase®. The chemical process provides greater resistance to pitting, as well as excellent stress corrosion performance to provide longer, leak-free service life.
Article contributed by the Process Control Team. Original article published at LNG Industry in September 2015.
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Increasing customer demand requires new process applications with needs for reliable lubrication and resistance to galling under stringent conditions of temperature, pressure, vacuum, corrosive environments, process sensitivity to contamination, product life, and maintenance requirements. The various applications within power generation and industrial and chemical processing have advanced lubrication needs. Specifically, this blog is related to the science of molybdenum disulfide coatings in compression fittings. In demanding environments, such as power generation plants, where tubing connections are exposed to stringent requirements and extremes, consistent leak-tight performance is critical and molybdenum disulfide coated fittings provide a solid solution.
Lubrication evolution increases demand
Molybdenum disulfide is a naturally occurring black colored solid compound that feels slippery to the touch. It readily transfers and adheres to other solid surfaces with which it comes into contact. Its mineral form – called molybdenite – was commonly confused with graphite until late in the 1700s. Both were used for lubrication and as writing material for centuries. Wider use of molybdenite as a lubricant was impeded by naturally occurring impurities that significantly reduced its lubricating properties. Methods of purifying molybdenum disulfide and extracting molybdenum were developed late in the 19th century, and the value of molybdenum as an alloying addition to steel was quickly recognized. The demand for a domestic source of molybdenum during World War I resulted in the development of the Climax mine in Colorado, which started production in 1918 and continued into the 1990s.
The availability of high purity molybdenum disulfide spurred extensive investigations into its lubrication properties in various environments during the late ’30s and ’40s. These investigations demonstrated its superior lubrication properties and stability under extreme contact pressures and in vacuum environments. These investigations resulted in extensive applications in spacecraft.
Download our white paper Molybdenum Disulfide - The Ideal Solid Lubricant and Anti-Galling Material for a closer look into the science behind high-performance compression tube fittings required for demanding environments.
Molybdenum disulfide’s exceptional lubricity is a consequence of its unique crystal structure, which is made up of very weakly bonded lamellae. The lamellae tend to align and adhere to contact surfaces, particularly under conditions of sliding and pressure, as shown here. This “burnishing in” of the molybdenum disulfide gives it its exceptional performance life.
Since molybdenum disulfide is a solid phase, it is not “squeezed out” like liquid lubricants under conditions of extreme pressure. The lamellae are very “hard” to forces perpendicular to them. This combination of properties provides a very effective “boundary layer” to prevent the lubricated surfaces from contacting each other.
The surfaces of objects are generally rough on a microscopic scale. When two objects are in contact with each other, they actually “touch” at very small regions of contact (i.e., asperities).
These contact regions have considerably less area than the bulk surface area, typically in the range of 0.5 to 0.001 percent of the bulk area for a machined metal surface, and consequently, the stresses at these contact points are considerably higher than the stresses calculated for the bulk surface area. When these objects slide relative to each other the frictional forces add to the stresses at the contact points, and the resultant stresses may be sufficient to cause deformation of the contact points.
When stainless steel objects slide against each other under high load, they will “gall” or “seize” due to the deformation at the contact points. The objects will actually “cold weld” themselves to each other, which is indicated by the transfer of material from one object to the other on the sliding surfaces. This causes a very rapid increase in friction, quickly to the point that further sliding is impossible without damage to the objects. To prevent this, it is necessary to introduce an “anti-galling” or “anti-seizing” agent between the surfaces. This is a substance that can maintain separation of the surface asperities under high compressive loads – that is, to provide a “boundary layer” between the surfaces. Anti-galling materials are generally very thick grease-like substances or solid materials in powder or plated layer form. Molybdenum disulfide is an ideal anti-galling compound because of its combination of high compressive strength and its adherence (ability to fill or level) to the sliding surfaces.
There are many methods of applying molybdenum disulfide to a surface, from “high tech” techniques such as vacuum sputtering, to simply dropping loose powder between sliding surfaces. The most versatile technique is the application of the powder mixed with a binder and a carrier to form a bonded coating. The binder may be a polymeric material or several other compounds, and the carrier may be water or a volatile organic. The characteristics of the molybdenum disulfide powder, the binder, the carrier, and particularly the application process must be carefully developed and controlled to optimize the performance of a specific product. A properly developed bonded coating of molybdenum disulfide can provide exceptional lubrication performance over a temperature range up to approximately 500°C, under very high pressure and corrosive exposure conditions for extensive lifetimes.
Molybdenum disulfide in compression fittings
During fitting make-up, the ferrule(s) is driven forward into the body seat and tubing surface as the nut is turned per the makeup instructions. The ferrules seal at contact points with the fitting body seat and tubing surface. The fitting is carefully engineered such that the ferrule and tubing do not rotate with the nut, moving only in the axial direction. This is critical to forming a high integrity leak-free tubing connection during the first make-up and subsequent remakes. Therefore, the sliding takes place between the back of the ferrule and the flange of the nut under very high pressure. This region of contact between the nut and the ferrule must have excellent lubrication for the proper action to occur during make-up to ensure ease of assembly, low make up torques, and optimum fitting function. The nut is “pulled” against the ferrule during make-up by the threads, which are also sliding under very high pressure and require high-performance lubrication.
Stainless steel compression fittings have the additional problem of preventing galling in these areas of sliding under very high contact pressures. This requires a “boundary layer material” – a substance that maintains separation of the surfaces during sliding.
Our instrumentation engineers have developed and used a bonded molybdenum disulfide coating on the nuts of our premium CPI™ compression fitting products for 30+ years. These fittings are readily recognized in the field by the “black nut” – the molybdenum disulfide coated nut, and have been providing exceptional service in many demanding applications.
The molybdenum disulfide coating has been carefully formulated and processed to optimize the performance of the CPI™ compression fitting. This fitting, with its single ferrule and the molybdenum disulfide, coated nut, has easy initial make-up with very low torque, consistent remake, and exceptional, leak-tight performance under demanding power generation applications including pressure, temperature, corrosion exposure, and vibration.
One product, multiple applications
We also offer a “Moly Inside” nut for use with our CPI™ and A-LOK® compression fittings. This is an optional version of our premium compression fitting products with the molybdenum disulfide coating only where it is needed, on the inside surfaces of the nuts. This offers the same low make-up torque and consistent remake-ability of the standard CPI™ compression fitting in both the CPI™ and A-LOK® versions due to the use of molybdenum disulfide on the critical mating surfaces of the interior threads and flange of the nut, but without the molybdenum disulfide on the external surfaces to rub off onto hands, gloves, or other equipment for industries requiring a “clean” appearance.
Download our white paper Molybdenum Disulfide - The Ideal Solid Lubricant and Anti-Galling Material for a closer look into essential attributes of high-performance compression tube fittings required for extreme environments.
Article contributed by Kevin Burke, marketing manager, Instrumentation Products Division, Parker Hannifin.
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In the quest for a decarbonised society there is no doubt that Hydrogen as an environmentally friendly fuel source is gaining a lot of popularity to become the fuel of the future. And the hydrogen revolution is happening now. Driving the ecological transition, hydrogen-based technologies are rapidly evolving, mass entering the market and becoming part of our daily lives. From clean power generation to environmentally friendly cars, the possibilities are endless.
The transportation sector is a prime example of how hydrogen technologies are taking off and making truly sustainable mobility more tangible than ever. Heavy trucks with hydrogen-powered cells are already hitting the roads, and although developing a global hydrogen refuelling infrastructure might take several years or even decades, the commitment to hydrogen economies from governments all around the world will certainly accelerate its pace.
The hydrogen challenge
Hydrogen is the most abundant element in nature and its versatility can offer compelling advantages as an accessible, sustainable and efficient alternative source of energy.
However, hydrogen can be very damaging to most metallic materials, causing what is known as hydrogen damage or hydrogen attack. Hydrogen is an extremely small particle and hydrogen degradation is directly connected to its capability to be easily absorbed by metals coupled with the high mobility those particles have at microstructural level.
Nearly every metallic material can be susceptible to hydrogen damage, and there are several forms of hydrogen degradation. Hydrogen embrittlement cracking is the most common form and affects the three main areas of industries that use hydrogen:
Fig. 1. Embrittlement process.
Embrittlement occurs when a material loses ductility and becomes brittle as a result of the diffusion of hydrogen into the material. The hydrogen atoms find preferential places in the structure of the material, modifying its physical properties and its mechanical behaviour. The result is a loss of ductility which makes the material more brittle and more susceptible to cracking. Hydrogen can be a silent assassin, weakening the material slowly and without any clear signs of damage, often leading to critical failure.
The effect of hydrogen embrittlement is determined by three main challenges:
Hydrogen and stress need to be present on a susceptible material for hydrogen-assisted fracture to happen. Firstly, hydrogen absorption can happen at both production and service stages. Processes such as uncontrolled melting, electroplating or welding can promote the pre-charge of hydrogen into a given metal.
In terms of microstructure, and as a rule of thumb, materials that bestow high mechanical strength or show a great number of defects and inclusions are likely to be more susceptible to this type of failure. The severity of hydrogen embrittlement is also a function of the operating temperature, with low temperatures being the worst case scenario in terms of material ductility and higher temperatures in terms of hydrogen absorption rate.
The factors that can affect the quality of the microstructure are numerous and have been widely documented by the materials society. Due to the complexity of the subject, the effect of microstructure as a major contributing factor to hydrogen behaviour, cannot be evaluated in simplistic terms. Taking one variable in isolation is not enough to guarantee the quality or performance of a given component and can be misleading. For example, a material grade with a ‘perfect chemistry’ or with high levels of a particular ingredient can still result in a very low quality product.
The common consequences of improper and non-controlled material processing, heat treatment and/or manufacturing operations are high densities of undesirable phases and inclusions in the raw material. These will inevitably lead to fatal and premature hydrogen assisted cracking during service in demanding H2 environments.
The mechanics of the application also play a major role. Stress states in components can be caused by the presence of residual stresses associated with certain fabrication techniques as well as stresses applied during service. Improper product design and improper installation can cause overloading of stress onto the material. All of these factors can cause premature failure of components in Hydrogen service.Can hydrogen embrittlement be prevented?
When it comes to handling hydrogen, material and equipment selection becomes, more than ever, an essential ingredient for success.
According to the International Industry Standard ISO 15916-2015, due to the fact that most metals are susceptible to different levels of H2 embrittlement, materials of construction and suitable equipment must be carefully selected to avoid failure when hydrogen exposure is anticipated. The positive news is that hydrogen embritllement can be prevented. End users need to pay special attention to the materials of construction and the quality of the equipment that goes into their assets.How Parker is at the front end of innovation for the hydrogen market
As a manufacturer of pressure containing equipment, Parker has decades of experience in serving hydrogen applications. Parker products are designed to minimise the risk associated with corrosion and hydrogen attack and deliver successful performance in the field. The raw materials that we use are fully traceable and closely controlled from melting stage to the finished product.
In addition, our manufacturing processes are selected to ensure minimum operating risk in hydrogen environments. As well as Stainless Steels (the prime material of choice for the H2 transportation sector), we can offer a variety of nickel alloys for a wide range of other applications.
Parker's portfolio also includes EC-79 approved products. The EC-79 approval (the Regulation of the European parliament and the Council of 14th January 2009 on type-approval of hydrogen powered motors) is an EU normative for components and systems which are installed on hydrogen-driven vehicles. Product ranges certified to this regulation are extensively tested to guarantee the safety and performance of H2 equipment under different pressures, electric, mechanical, thermal or chemical conditions.
As a leading manufacturer in motion and control technologies Parker offers a wide range of products orientated to the hydrogen market.
Fig. 4. Parker A-LOK® two ferrule tube fittings
EC-79 approved for use on-board hydrogen vehicles up to 350 barg pressures.
Article contributed by Clara Moyano, innovation engineer - Materials Science, Parker Hannifin, Instrumentation Products Division Europe.
Of the many transport fuel choices available today, none plays a more strategic role than natural gas in having an immediate and major positive economic and environmental impact. But of the two most widely available – CNG and LNG – which is most appropriate?
Onboard vehicle filling stations - Compressed Natural Gas
Compressed Natural Gas (CNG ) is a fuel produced by purifying natural gas and cooling it to less than 1% of its volume and stored onboard a vehicle in a compressed gaseous state at a pressure of up to 3600 PSI. CNG is used in light-, medium, and heavy-duty vehicle applications.Gas transport and storage - Liquidized Natural Gas
LNG is a fuel produced by purifying natural gas and cooling it to -161°C to turn it into a liquid. LNG is suitable for trucks that require longer ranges and typically used in heavy-duty vehicles. Parker Bestobell’s cryogenic valves are widely used on road LNG trucks transporting LNG to fueling station sand storage tanks.
On-board vehicle filling station - Hydrogen
Hydrogen can be produced from fossil fuels, biomass, and water electrolysis with electricity. The environmental impact and energy efficiency of hydrogen depends on how it is produced. Hydrogen-powered vehicles work by converting compressed hydrogen from their fuel tanks into electricity that powers their engines. This process generates only water vapor and heat emissions.Solutions
Alternative fuel solutions for trucks and buses contribute to a better world.
Alternative fuels (CNG, LNG, H2 ) are emerging as strong and viable alternatives to traditional fuels for HGVs for many reasons: energy security, economics and the potential to reduce emissions and noise. Parker’s solutions for reliable fuel distribution and regulation help OEM’s around the world drive towards a better future.
Contributed by the Process Control Team.Related alternative fuel content:
Corrosion is a major challenge for many design engineers and specifiers in the general industrial market. Choosing the right materials is critical to ensure optimal performance, as even the highest quality products can fail if not used properly.
Materials selection: three key questions to answer
Engineers must carefully analyse the proposed operating environment when selecting materials for industrial applications. Answering three important questions will help unearth potential problems and provide useful guidance on appropriate materials to use.
Fig. 1 Materials selection: factors to consider to minimize Stress Corrosion Cracking (SCC)
The three questions to consider are:
Q1. Is the material composition susceptible to cracking?
As this diagram shows, if potentially corrosive media (such as chloride containing compounds) needs to be contained and the material is susceptible to cracking, corrosion can occur. Material susceptibility is not purely about chemistry, though; factors such as material processing, specific microstructure and surface condition are also important.
Q2. Is the application environment potentially corrosive?
Environmental factors can include a range of parameters – chemical composition, flow rate, temperature, or electrode potential, which can be aggressive and lead to
corrosion and cracking.
Q3. Is the material concentrated load under tensile stress?
Stress can be imparted into a component in various ways – from service stress and vibration to residual stress derived from manufacturing processes or heat treatment.
Answering these questions helps to build a picture of what is appropriate for the individual circumstances. A small investment of time upfront can make a big difference to the longer-term success of an installation.
Materials selection and cost-efficiency
If a specific mix of materials was used successfully for a previous project, it can be tempting to rely on what has gone before. But that is not always a good idea.
With more than 300,000 product materials to choose from, materials selection presents a big challenge for many specifiers. It’s easy to feel spoilt for choice or be overwhelmed by the range of options available. But adding extra elements can complicate things… sometimes, just one material might be enough for the job! It’s important to know when adding a small amount of an element could increase costs, without any obvious customer benefit.
Conditions in many industries have changed; and it’s important to keep adapting materials to reflect this. Climate change is also key. For example, if summer temperatures have raised by a few degrees, some materials suitable in the past may no longer be appropriate.
It’s worth bearing in mind that:
Not all alloys are created equal, and even identical chemistries can lead to different final products. Parker’s 316 stainless steel A-LOK® tube fittings with min. 10% of nickel content has operated successfully in critical applications for 50+ years.
Good steel combines chemistry and processing. Parker tightly controls all specifications in terms of raw material quality, corrosion performance, mechanical properties, and heat treatment. Production routes are controlled from melting to a machined product; this ensures that customers get the best possible performance for their applications and a material that offers full traceability.
Managing risk when mixing materials
To get optimal results from your budget, it’s helpful to use the best material for the job, at the lowest possible cost. But when budgets are under pressure, some engineers may mix alloys on the same application.
Although using dissimilar materials seems like an easy way to save costs, it can be risky. Just because something looks strong and resilient, doesn’t mean that it will last for a long time. And mixing dissimilar materials for instrumentation can lead to SCC, where localised attacks at one point gradually progress to other areas of the system. SCC can lead to fatal failures.
NORSOK Standard M-001 Materials Selection states that
“‘At galvanic connections between dissimilar materials without isolation, it can be assumed that the local corrosion rate near the interface is approximately 3 times higher than the average corrosion rate. Particular systems may have higher corrosion rates depending on area ratio and material combinations.”
If a proposed application is highly demanding and requires expensive material, that’s likely to be important across the whole system. Ultimately the whole system operates in the same environment, contains the same media, and operates at the same pressure; therefore, it makes sense to use the same material throughout, rather than (say) using one material for the tubing and another for fittings.
Not everyone has access to a materials expert with their projects, but Parker’s specialist metallurgists bring many years of experience. This helps engineers identify the best materials for an application and predict likely failure risks. For example, using 316 stainless steel in seawater may not be a good choice because it is more susceptible to corrosion; but alternatives such as super austenitic stainless steel 6Mo (UNS S31254) or nickel alloy C276 (UNS N10276) may work, as they are designed to withstand chloride-containing environments with greater resistance to pitting or crevice corrosion.
Improving engineer confidence and skills with SBEx training
For some customers, specialist training provision can reduce the likelihood of potential fitting failures. For example, Parker’s Small Bore Expert (SBEx) training provides valuable guidance on correct fitting assembly and material selection. Suitable for fitters, technicians, and maintenance personnel, this course helps organisations to save time, reduce overheads, and increase safety.
Download our brochure with tips on smarter materials selection for corrosion control.
Article contributed by Clara Moyano, innovation engineer - Materials Science, Parker Hannifin, Instrumentation Products Division Europe
Prevention is better than a cure. In coal mining, these words offer particularly good guidance. Underground mining presents numerous hazards ranging from structural collapses, flooding and explosions. The tremendous amount of dust generated by activities in a coal mine creates breathing-related problems for workers as well as maintenance issues for machinery. Dust can also create a potentially explosive environment. Injuries and deaths occur every year either from accidents or health issues caused by exposure to coal dust. Mining companies can dramatically reduce these risks by applying rigorous dust suppression safety measures.
This blog investigates dust suppression methods and evaluates preventative versus corrective techniques that can effectively be used to suppress dust in underground coal mines, reducing the risk to workers and equipment.
Coal dust is a known carcinogen that causes miners’ lung disease (pneumoconiosis). Dust in the atmosphere can also create an ignition hazard when mixed with gas. Coal dust buildup is often a root cause of premature maintenance and failure of mining equipment. To this end, preventative suppression is critical.
There are a variety of ways to suppress dust in coal mines that offer a varying degree of effectiveness and efficiency. The most common methods are:
Bag filter system uses fans to circulate the air and trap the solids in a bag. However, this type of system is maintenance-intensive and requires bag filter change-outs — which is not conducive to work in an underground mine.
Dry fog system requires electricity, making it impractical for work below ground level.
Water is an ideal solution because it takes advantage of the mine's existing water supply, forming it into a spray to suppress the dust as soon as it is generated at the coal extraction point and all other areas where dust is generated.
Preventative vs. corrective dust suppression using water Preventative dust suppression
Logically, if a problem can be prevented from happening, then the time and cost of fixing it can be saved. Preventing dust from becoming airborne is critical in dust suppression. Three important elements to successful preventative suppression using water include:
Control pertains to how the water is controlled. It may be controlled by the presence of coal on the conveyor or by the belt’s motion. In either case, the water is isolated before entering the system.
Filter technology is used to remove contaminants from the water to assure reliable system operation.
Spray refers to a predetermined volume and pattern in which the water is delivered to the coal before the dust is generated.
The figure below shows a typical belt conveyor transfer point dust suppression system has two options: paddle valve (A) or belt-driven valve (B). Both are designed to operate only when there is coal on the conveyor.
Corrective or symptomatic dust control is implemented after the dust is created and is more challenging than preventative dust control. Dust particles come in a range of sizes with some as small as 10 µm which is invisible to the human eye. These small particles are the most dangerous to workers and equipment because they can remain airborne for long periods of time and eventually find their way into miners’ lungs, onto and into machinery as well as outside of the mine itself. Small particles are also the most difficult to remove from the atmosphere. Airborne coal dust can be addressed correctively using sprays. The principal is that the dust agglomerates with the water, causing it to fall under gravity. However, if the water droplets are too large, then the airborne dust particles are just moved around, resulting in very little dust being removed. To effectively remove the dust, the water droplets and dust particles must be the same size. Hence, the design of the spray head is of great importance. With preventative suppression, the size of the particle is less important.
Dust suppression in Columbia | case study
Parker Conflow, a leader in the industry, works continuously with mining companies and equipment manufacturers to enhance products for preventative dust suppression. In one case, at CI Milpa in Colombia, a manufacturer of metallurgical coal, Parker Conflow engineers designed two dust suppression systems for a mine as well as a fire suppression system on a roadway.
“We are focused on continually improving the efficiency and safety of our production sites and the Parker Conflow systems are an important part of this. We chose to work with Parker Conflow, because of the company’s expertise in the manufacture and installation of dust and fire suppression systems and are very pleased with the result.”
— David Fernando Jaimes Mojica, CI Milpa
Preventive coal dust suppression is vital to ensuring the health and safety of workers and protecting mining equipment from costly downtime and failure. For over 60 years, Parker Conflow has been providing dust suppression, fire suppression and water control equipment and services that help protect workers in the coal mining industry worldwide.
After more than a century of experience serving our customers, Parker is often called to the table for the collaborations that help to solve the most complex engineering challenges. We help them bring their ideas to light. We are a trusted partner, working alongside our customers to enable technology breakthroughs that change the world for the better.
This blog was contributed by Gary Wain, product manager, Parker Conflow.
The Oil & Gas industry sector is driven by safety and has been for over 60 years around the globe. Whilst the industry has had issues with incidents, it has been proven that by adhering to good working practices and following recommended installation techniques and procedures, these incidents can be minimized.
In summary, well trained, skillful engineering teams can help to reduce incidents and improve safety on Oil & Gas facilities. The key to this is for Owner Operators to ensure personnel are well trained and competent in their roles.Human errors are the main cause of Hydrocarbon Release (HCR) incidents
In the North Sea, HCR have been measured for many years and it is estimated that over half of HCR incidents are linked to or caused by human error (Source: Hydrocarbon Release Reduction Toolkit, Step Change in Safety).
Here, we will look at these human errors and identify the common ones in Small Bore Tubing (SBT) systems that can occur in Oil & Gas installations.
In instrumentation systems, leaks represent one of the most critical safety hazards. Common faults include, but are not limited to:
As these systems can carry hazardous substances, they have the potential to cause harm to personnel and equipment.Well trained personnel mean fewer issues
A well structured Small Bore Training (SBT) course delivered by well trained and experienced individuals can help eliminate these risks. Typically, a good course should address:
The objective of such training is to up-skill new recruits and apprentices whilst at the same time offering helpful tips and reminders to more experienced engineers. Everyone should leave the course having learned something new and being able to install connections safely.Parker Small Bore Expert (SBEx) training course
The Parker Small Bore Expert (SBEx) training course is designed to offer all of the above and the benefits to the engineers are:
It’s a sobering thought but the HSE (in the UK Oil & Gas industry) has consistently found that approx. 26% of SBT connections contain faults and typically these faults are aligned with the ones identified above (Source: Hydrocarbon Releases Offshore Information Sheet No. 2 / 2009, HSE).
Investment in the Parker SBEx Training Course can help address all of these challenges. Our goal is to help eliminate installation errors and reduce the potential for pressure related accidents. At Parker we are committed to providing your engineers with the right training courses via our trusted partners and distributors around the globe.
‘’Hydrasun, for over 30 years, continues to support the global energy sector, and other industry sectors, with training and technical competence at the heart of our service delivery. Hydrasun’s commercial training department has delivered over 1000 Parker SBEx courses to industry, training over 2700 delegates, in just the last 6 years alone, supporting our customers training and competency requirements, focussing on raising standards on safe working practices and procedures, and to ensure that Industry continues to deliver safe and reliable operations.’’
Stuart Gardiner, Hydrasun Group Operations Director (Directly responsible for HSE, Quality and Training)
Article contributed by Dave Edwards, Fittings Product Manager, Parker Hannifin Manufacturing Ltd., Instrumentation Products Division, Europe
One of the biggest challenges faced by transport managers is how to decide exactly which product you require to meet your needs. It all depends on what your vehicles are running on and carrying; why, where, when. A highly-pressurised liquid fuel in sub-zero conditions requires very different sorts of fittings to a gas in tropical or desert heat. Here is the quick guide to using our ‘STAMPER’ method to maximise quality and reliability when it comes to specifying and choosing the right product for the transportation industry.Wrong product, wrong results
With almost limitless variables in different parts of the industry across the world, it’s no surprise that companies sometimes request the wrong parts, and end up paying the price in reduced productivity, missed schedules and downtime. All of Parker’s products are manufactured to the highest, quality-controlled specifications, but if it’s the wrong part in the wrong place at the wrong time, then performance and safety might be at risk. And during the current pandemic emergency, that’s something you can definitely do without.STAMPER makes it simple
To keep things easy and avoid this problem, follow the STAMPER approach to identify and order exactly what you need. STAMPER is the easy-to-remember acronym that will set you and your customers on the right route to reliability. Just seven letters to cover everything you need to consider, and put you in control.So here is STAMPER:
Fittings sizes vary enormously, between 6 and 25mm – which do you need?
In a global market, you need to cater for outside conditions as cold as -40oC or as hot as +60oC, and engines running at +140oC or even higher. Can the components in your systems handle such extremes?
Vibrations from engines and road surfaces can affect how products perform, and temperatures can fluctuate widely within a few hours.
What materials are you using or transporting, and what sort of connections do you need to suit the substances on board?
Working pressures up to 350 Bar are commonplace and may be double this in the near future. Is what you’ve chosen up to the job, and will it last for as long as your vehicles?
Salt, sand, chemical spray and other road contaminants can cause corrosion, and the demands from these can change from region to region. Are you fully protected?
Parker’s robust supply chain and flexible production offers you peace of mind, backed up by the experience and problem-solving abilities of our expert team. We focus on supplying the right products, so you can keep your eyes on the road and your business.
This infographic shows how STAMPER can help you secure quality and reliability for different types of natural gas fuels that demand precisely the right sort of connection. Download full infographic.
STAMPER will ensure you ask yourself the right questions to pinpoint the most suitable parts for all your transport purposes. Try it today, and contact us if you need any extra help or advice before ordering from our range.
At Parker, we know transport and want you to feel confident and comfortable in the driving seat when it comes to choosing the products you need.
Be sure and safe with STAMPER.
Article contributed by Dave Edwards, Fittings Product Manager, Parker Hannifin Manufacturing Ltd., Instrumentation Products Division, Europe