CNG Fuel System Inspections: Not a Task for the Untrained Technician By Annalloyd Thomason,
Vice President/General Manager, NGVi
During the recent American Trucking Association's Technology Maintenance Council, I attended the "CNG Tank Inspection" Task Force meeting, and I could not believe what I was hearing. The chair of the Task Force was putting forth the position that "CNG tank inspections" are very simple, straightforward processes that can be learned from a handbook or DVD-based training course. He also hypothesized that technicians do not require the level of training and certification being advocated by the NGV industry today.
Based on our 25 years' of experience training NGV technicians, I expressed my strong disagreement with that position. Fortunately, my opinion was shared by most of the vehicle manufacturers and current NGV users in the room. Here are a few reasons why minimizing the knowledge and skills required to conduct a thorough CNG fuel system inspection is at a minimum foolish and at its maximum, downright dangerous.
Technicians New to NGVs Are Unfamiliar with High-Pressure Gaseous Fuel Systems
Most technicians working in dealerships or fleet operations are highly familiar with diesel or gasoline systems. As NGVs are introduced, technicians have no knowledge of a high-pressure gaseous fuel system and how very different they are from liquid fuels. Unless a technician has been properly trained, they may "learn" maintenance practices that are unsafe—and they may unwittingly pass these along to their co-workers. The first step in ensuring safety for technicians charged with the task of conducting CNG fuel system inspections is thorough training on the components and safety practices specific to NGVs. This doesn't happen by reading a handbook or watching a DVD training course—it happens most effectively with a combination of instructor-led and hands-on training.
High-Pressure Can Be a Serious Safety Hazard
Pressure is the number one safety hazard of CNG-powered vehicles. CNG is stored onboard natural gas vehicles at 3,600 pounds per square inch (psi). Although these vehicles are equipped with extraordinary safety features, an incident resulting from undetected external damage to the CNG fuel system can cause severe bodily harm or even death. CNG fuel system inspections are designed to detect damage to any component of the system, including the cylinders, so that unnecessary safety risks are not taken and ultimately lives are not jeopardized.
CNG Fuel System Components and Their Possible Damage Scenarios Are Unfamiliar to New NGV Technicians
Damage to CNG fuel systems, including cylinders, comes in many shapes and forms and is not always easy to identify. When conducting the detailed visual inspection, NGV technicians must examine all high-pressure natural gas components including cylinders, brackets, valves, fittings, lines, regulator, coalescing filter, fuel receptacle, and shields in addition to the installation or mounting of those components.
If technicians have not had thorough training, including applicable hands-on practice in identifying, measuring and classifying damage levels, they are not prepared to do their jobs properly.
Codes and Standards Governing CNG Fuel Systems Are Detailed and Require Application and Interpretation
Technicians who perform CNG fuel system inspections require both knowledge of codes and standards for CNG fuel system installation as well as skill in applying that knowledge. They must be able to readily interpret and apply codes and standards covering CNG fuel system components, identify and describe NGV industry documents, and understand mandated inspection requirements. The codes involved include U.S. DOT FMVSS 304, ANSI/CSA NGV 2, NFPA 52, ANSI/CSA PRD 1, ANSI/CSA NGV 3.1, and CGA C-6.4. Additionally while performing each fuel system inspection, the inspector must have access to and be able to understand and properly apply the cylinder manufacturer’s maintenance and repair guide. This is not "nice to know" information—it is essential information to perform their jobs.
Safety and Risk Management Are the Number One Goals
The bottom line is this: responsible NGV fleet operators and servicing dealers have safety of employees, customers and the general public as their number one goal. The topic of safety is often minimized in the minds of management until there is an incident involving the CNG fuel system. If this occurs, the vehicle owner, the CNG fuel system inspectors and numerous other organizations up the "food chain" (such as manufacturers or distributors) likely will be named in litigation. Everyone involved in the process could only hope that the technicians who provided the CNG fuel system inspection have been well trained, certified and followed CNG fuel system inspection procedures to the letter—including documentation.
Yes, NGVs are new territory for most technicians. Yes, CNG fuel system inspections are an unfamiliar task. Yes, there is a cost associated with training and certifying technicians to conduct effective CNG fuel system inspections. But in the long run, it would be irresponsible to minimize—or even skip—the process of training technicians to perform a job that might save lives.
Perspectives With Michael R. Wedding, Senior Application Engineer, Valvoline By Robin Skibicki, Marketing Coordinator, NGVi
In 1866, Dr. John Ellis founded the Continuous Oil Refining Company. He had developed a highly-effective lubricant while researching medicinal uses for refined crude oil. This product addressed the sticking valves and other issues that were constraining the performance and advancement of the steam engine industry. Dr. Ellis named the product “Valvoline”, referring to “olein”, which is fat or ester. The name and logo were trademarked in 1873, making it the first and oldest trademark in lubrication.
Today, Valvoline serves more than 100 countries, and continues to achieve notable firsts with both products and performance accomplishments. NGVi had the opportunity to speak with Valvoline’s Senior Application Engineer, Michael R. Wedding, about their involvement in the natural gas vehicle market.
How did Valvoline enter the natural gas vehicle and natural gas fueling industry?
Valvoline was producing oils specifically formulated for natural gas fueled vehicles at least as early as the 1990’s. These products were recommended for urban buses, delivery trucks, and other service fleets fueled by CNG, LNG, or propane. They were marketed for use in Cummins, Detroit Diesel, John Deere, and Caterpillar dedicated natural gas engines for vehicular use.
What products do you offer for the natural gas vehicle and natural gas fueling markets?
At this time, our commercial offerings are focused on engine oils formulated for the specific demands of medium- and heavy-duty vehicle engines fueled by 100% natural gas and therefore spark ignited.
Our Premium Blue® GEO products carry the approval and endorsement of Cummins for use in all Cummins Westport engines, as well as approvals from Detroit Diesel, Volvo and others. Our newest GEO product, Premium Blue GEO SAE 5W-40 is the only cold temperature engine oil approved by Cummins to address cold starting issues at extreme low temperatures. Why do natural gas vehicle engines require different oil than gasoline or diesel engines?
There are multiple factors to be considered when comparing natural gas and diesel engines. The cleanliness of the natural gas does not necessitate the high levels of alkalinity and dispersants. These additives found in diesel engine oils can cause multiple issues if used in heavy-duty natural gas engines. Extremely hard deposits can form in the combustion chamber when metallic additives are exposed to the elevated combustion temperatures of natural gas. These deposits retain heat causing pre-ignition and/or piston failure. Deposits on the exhaust valve can lead to compression loss and torched valve seats. Additionally, the dispersants needed to keep diesel soot in suspension can suspend water molecules, a by-product of natural gas combustion. This water leads to foaming and poor lubrication.
Light-duty and passenger car manufacturers have not yet recognized a need for differentiation in their engine oil when replacing gasoline with natural gas.
Either extreme cold or heat creates challenges for the transportation industry. How do the oil formulations for natural gas vehicle engines and natural gas compressors perform under these conditions?
Our Premium Blue GEO 5W-40 has been formulated with synthetic base oils for an improved viscosity index and cold temperature performance. This helps to reduce, or may even eliminate, cold starting issues previously experienced with natural gas engines by reducing the power needed to crank the engine and pump the oil. These same synthetic base stocks provide better high temperature oxidation protection.
Both Premium Blue GEO 15W-40 and 5W-40 are specifically formulated to address the needs of the natural gas engines with their high combustion temperatures. The viscosity of our 15W-40 product is comparable to our competitors’ natural gas engine oils.
Both oils have similar viscosity at the operating temperature of the engine. The noteworthy viscosity difference of the two products is at low temperatures. The number before the “W” dictates the cold temperatures at which the oil must meet viscosity limits:
5W evaluated at -30°C (-22°F) and -35°C (-31°F)
15W evaluated at -20°C (-4°F) and -25°C (-13°F)
The number after the “W” (40 in this example) represents the viscosity of the oil as measured at 100°C (212°F).
Is there a Cummins bulletin number addressing this lower viscosity oil? Is there a new Cummins Engineering Standards (CES) number?
CES 20074 continues to be the standard for oils used in Cummins Westport Natural Gas engines. The results of our extensive field testing with Cummins demonstrated the performance required for Cummins to allow Premium Blue GEO 5W-40 labeling as conforming to CES 20074. Cummins is now in the process of updating their specification(s) related to these engines and we expect there to be provisions for testing and approving different viscosity grades.
Can you tell us about any natural gas vehicle fleets that are successfully using Valvoline Premium Blue GEO engine oil?
In a recent video released to the “Valvoline HD” YouTube channel, we discussed two of our Premium Blue GEO customers, and their testimonials. Ozinga Ready Mix may be the most recognizable as they also offer fueling solutions as Ozinga Energy. Dillon Transport is the line-haul operation that is featured in the video, as well. We continue to gain customer accounts, specifically in the colder regions of the country. You can view the YouTube video below, or by clicking here: https://www.youtube.com/watch?v=el8nWWK_zOI
Does Valvoline produce synthetic lubricants for natural gas compressors? What are they?
At this time, we do not have a commercially available product for the compressor application. Our Certified Lubrication Specialists often work with our distributors to recommend the best commercially available product when needed to complement our other offerings.
What are the primary advantages of using synthetic oil in a natural gas compressor? The performance advantage of synthetic base oils is primarily related to the extreme temperature performance. Whenever any gas or air is compressed, the temperature is increased proportionally.
Moving on to more specific industry topics, what are Valvoline’s expectations for natural gas vehicle fueling in North America in the next few years?
Even with the lower fuel prices we are witnessing for diesel and gasoline, we expect that the number of natural gas vehicles and stations will continue to increase. The introduction of the ISX 12G has provided an option to some of the heavier haulers that were hesitant until now. Continued pipeline construction will also increase the availability of natural gas domestically for years to come. How has the demand for natural gas vehicles and fueling shaped your company’s production? Has it changed its priorities?
If you look at the percentage of production, you may not see any indication of change. Our overall company growth has likely kept fairly close pace with the GEO increases. The difference is in our technology and development efforts. Natural gas vehicle use, particularly in commercial vehicles, is still very much an industry in its infancy; therefore we are motivated to stay ahead of our competition with new and better products. If you recall, we have found this to be a successful strategy since 1866. Valvoline remains a company primarily focused on lubrication.
Why should natural gas vehicle and natural gas fueling customers choose Valvoline? What are your competitive advantages?
We simply have the most advanced engine oils commercially available for heavy-duty natural gas vehicles. What we are equally excited about, however, is our unique position in the industry. Our technical staff enjoys the benefits afforded by operating our own certified engine lab, managing ongoing fleet field tests, and being partnered with the number one on-highway heavy-duty natural gas engine OEM. All of this research and testing enables Valvoline to provide exceptional service and products. Being on the front edge of development is good not only for Valvoline, but also for our customers.
As gasoline and diesel continue their unstable pricing pattern, dictated by the global energy market, natural gas remains inexpensive and steady. Using natural gas as a transportation fuel is still more cost-effective—especially for the medium- and heavy-duty truck applications.
According to a recent count by the International Association of Natural Gas Vehicles, there are more than 16 million natural gas vehicles operating worldwide, with over 160,000 in the United States. NGVs are among the safest vehicles driving on the road today. Yet,as more of them deploy, drivers must be adequately trained on the properties and characteristics of the fuel itself. They must also learn all necessary safety precautions and techniques while operating and fueling natural gas vehicles.
Since natural gas is a vapor and not a liquid, it has unique characteristics that distinguish it from other fuels. For instance, because it is lighter than air, natural gas will rise if leaked instead of pooling on the ground like, gasoline and diesel. It is either highly compressed or liquefied before it is stored onboard vehicles and thus requires different fueling equipment, procedures, safety protocols and handling.
Because of their daily operation and fueling of natural gas vehicles, drivers and fuel handlers must be able to identify and use CNG fueling station equipment and safety components. They should know how to locate and use emergency shutdown devices, quarter-turn manual shut-off valves, fire extinguishers, and other safety equipment.
Drivers and fuel handlers must also follow the specific steps and precautions involved in fueling CNG-powered vehicles. They should know what to expect during the fueling process. This procedure differs from traditional gasoline or diesel vehicles because it involves transferring high-pressure gas instead of merely pumping a liquid.
While fueling an NGV, for example, it is normal for a small amount of gas to escape the nozzle/receptacle connection when they are disconnected. Drivers may be able to detect the smell of gas for a brief period of time. Also, when fast-filling an NGV, it is normal that drivers may hear a whining sound which indicates that the vehicle is almost full. A lasting scent, however, or a distinct hiss that lingers is not normal and should be reported to fueling station maintenance.
It is also imperative that drivers and fuel handlers are able to identify the safety hazards and know what to do when they occur. For instance, they must remember to visually check O-rings before each fueling. An O-ring is fitted in the receptacle to ensure a gas-tight seal between the fueling nozzle and the receptacle. Whether fueling a heavy- or light-duty NGV, if the O-ring is missing or damaged, there may be a fueling failure. In this case, drivers should not connect the fill nozzle to the receptacle and they should have the missing O-ring replaced before attempting to fuel the vehicle.
Although natural gas vehicles have a solid safety record and there are a very low number of incidents involving NGVs, drivers need to know what safety protocols they should follow in case of emergency. On the vehicle side, they need to know what procedures to use in case of vehicle accident or fire, if a receptacle is leaking, and what to do if a heavy-duty vehicle’s methane detection system is activated. At the CNG fueling station, they should know what to do in case of fueling station accident or fire, major gas release, and in case of emergencies such as an earthquake or vandalism. For example, drivers and fuel handlers should know what to do if they encounter equipment warning lights or audible alarms at a CNG station.
Operating and fueling NGVs requires special awareness of safety procedures that are unique to these vehicles. Understanding NGVs and the technology for both vehicles and fueling can minimize the risk of accident in the shop, on the road or at a fueling station. In this new era when NGVs are becoming more and more prevalent, adequate training for vehicle drivers on the unique fuel systems and operating characteristics for NGVs is a must. For more information about online
Natural Gas Vehicle Driver and Fueling Training, visit www. ngvi.com/driver_safety.html.
Heavy-Duty NGV Maintenance
and Diagnostics Training
April 7-9, 2015
High Point, NC
June 2-4, 2015
This intensive three-day training course prepares technicians to understand the operation, maintenance, diagnosis and repair of heavy-duty natural gas vehicles and covers all natural gas heavy-duty manufacturers’ systems, including CNG and LNG, with major emphasis on Cummins ISL G-equipped vehicles.
Natural Gas Vehicle Institute is North America’s leading provider of training and consulting on natural gas as a transportation fuel.
Our services address the full range of natural gas vehicle and fueling issues, including:
Technical consulting services – Sizing and designing compressed natural gas fueling stations, vehicle assessments and technical assistance for fleets, CNG fueling station troubleshooting, natural gas vehicle maintenance facilities upgrades, liquefied natural gas fleet and fueling management.
Technical training – NGV Essentials and Safety Practices, CNG Fuel System Inspector Training, Heavy-Duty NGV Maintenance and Diagnostics Training, Light-Duty NGV Maintenance and Diagnostics Training, CNG Fueling Station Operation and Maintenance Training, CNG Fueling Station Design Training and CNG/LNG Codes and Standards Training for Fire Marshals and Code Officials.