09/01/2021
Will the frequent "jumping" of the fuel gun affect the fuel supply?
With the improvement of people's living standards, private cars have gradually become the mainstream means of transportation. Today, every household has a car on average. When you have a car, refueling is an essential thing. Generally speaking, when we refuel on the gas station refueling machine, there are two ways. One is to add a certain amount of fuel, which is what we often say add 100, 200, or 300. The other is to fill up the gas station directly.
Refilling a certain amount of fuel is very simple. The refueling machine calculates the fuel volume under a certain amount, and then outputs it through the fuel gun. When the specified fuel volume is reached, the output stops and the refueling is complete. So for the definition of full, what kind of situation is considered full? In fact, they are all self-styled fuel guns now, meaning that they will automatically jump when filled up, so we know that the fuel tank is full.
Many car owners have had the experience of "jumping guns" when refueling at gas stations. Some car owners will be puzzled by this phenomenon. There are even rumors that "the fueler pinches the gun several times in the middle, and you refuel less than normal." It's a lot..." I wonder how many people have heard similar words like this? It is normal to have such doubts. So, will the result of the "jumping gun" affect the amount of fuel?
First of all, we have a simple understanding of the principle of the jump gun. The jump gun requires the oil gun to have a pressureless self-sealing function. The pressure-free self-sealing oil v***r recovery oil gun is already the mainstream oil gun on the market. At present, in an environment where energy is gradually reduced, it is refueling. Energy saving, environmental protection and safety have higher requirements. Furen Precision has also developed this convenient pressure-free self-sealing oil-gas recovery nozzle in cooperation with Japan's Fuyong. This oil gun has the functions and advantages of full liquid self-sealing, pressure-free self-sealing, elevation angle self-sealing, one-handed operation, and light weight. Because the principle of all kinds of oil jumping guns is the same, now take the Seiko pressureless self-sealing oil v***r recovery oil gun as an example.
1.What is the reason for "jumping the gun"? The so-called jumping gun is the embodiment of the self-sealing function of the oil gun. When the oil is discharged normally, the main valve is opened by the trigger, and the oil flows from the main valve area to the auxiliary valve negative pressure area. The auxiliary valve negative pressure area is made according to the principle of Venturi effect, which produces negative pressure (with adsorption effect) at a certain liquid flow rate. , Replenish air through the self-sealing induction port of the barrel to maintain balance and stable oil output. When the oil flows through the self-sealing port, the self-sealing port cannot replenish air. The negative pressure acts on the pressure-sensitive control area to control the parallel pin connected to the main valve to move upward, and the main valve is moved forward and closed, and the fueling gun will be automatically closed, commonly known as Jumping the gun, the main purpose is to prevent oil overflow. Except for the possibility that the fuel dispenser frequently jumps the gun, the possibility that the fuel is full is excluded. There are two main reasons: one is that the air return pipe of the vent next to the fuel tank's fuel filler port may be blocked or deformed, resulting in poor exhaust of the fuel tank (this is more likely to occur when the weather is hot); the second is the fuel filler pipeline There may be clogging or poor oil flow. As a result, the self-sealing port of the oil gun cannot replenish the air and the oil gun automatically jumps. In addition, there is also a man-made operation that interrupts the refueling, the so-called "pinch gun". The "pinch gun" is related to the operating habits of the fueler, and is also a safe operation method for the fueler to prevent oil spills. Refuelers use experience to judge the oil level. When preventing the self-sealing function of the oil gun from failing, they often use the "pinch gun" operation to control the refueling process.
2. Does "jumping the gun" affect the amount of refueling? "Jumping the gun" and "pinching the gun" are common phenomena in the refueling process. In fact, if you want to figure out whether the amount of refueling is less or more, there is always a standard . The national quality and technical supervision department has strict requirements on the metering performance of fuel dispensers. Technical documents such as GB/T 9081-2008 "Motor Vehicle Fuel Dispenser", JJG 443-2015 and JJF 1521-2015 "Fuel Refueling Model Evaluation Outline" It clearly stipulates that the maximum allowable error of the fuel dispenser is ≤ ±0.30%, and the repeatability is ≤ 0.10%, so as long as the indication error and repeatability meet the requirements, we consider the metering of the fuel dispenser to be accurate. In order to verify the facts for market and production needs, Furen Precision has repeatedly carried out continuous refueling and multiple intermittent refueling tests with the same configuration, and the error and repeatability of the test data are within 0.05%, and the oil output of multiple intermittent refueling On the contrary, it is about 0.03% more than continuous refueling. According to reports, the Guangzhou Bureau of Quality Supervision organized a subsidiary of the Guangzhou Energy Institute (a legal metrological verification agency) to conduct such an experiment, randomly selecting three gas stations and conducting on-site comparison tests. The staff randomly selected three refueling guns from these three gas stations, and refueled each gun in two ways: normal refueling and "carton" refueling, and also conducted three large-flow and three small-flow inspections. The experimental results show that the maximum indication error is only four ten thousandths, that is, the error of four liters per 10,000 liters of fuel is within the allowable error range (plus or minus three-thousandths) of the metering verification regulations for the dispenser. In 2017, the Beijing Municipal Bureau of Metrology conducted a simulated vehicle refueling test verification at the gas station site. According to JJG 443-2015 "Regulations for Fuel Dispenser Verification", one type completes refueling at one time, and the other completes refueling after 10 interruptions. The maximum error of the difference between the two verification experiments is 0.04%, and the repeatability is not more than 0.1%. Both of them meet the requirements of JJG 443-2015 and judged as qualified. At the same time, the Bureau of Metrology also answered that many consumers are used to using fuel tanks as measuring instruments. Most brands of cars clearly indicate on the instruction manual that the “rated capacity” of the fuel tank is not actually the “maximum capacity”. Generally, the actual capacity of a fuel tank is about 10% larger than its rated capacity, which provides enough space for fuel expansion when its temperature rises. Some consumers think that there is oil overflow at the fuel tank port to be regarded as "full", and the gun jumps without seeing the oil and thinks that it is not full. In fact, this is related to the depth of the self-sealing oil gun inserted, and at the same time to prevent overfilling and causing safety accidents related. Some consumers like to use the oil meter on the dashboard as a measuring instrument. The oil quantity indicator can only roughly reflect the amount of remaining oil. As a reference range for judging when it is necessary to refuel, the deviation is still quite different from the actual data. The metering performance of the fuel dispenser under various conditions has been fully considered in the production of the fuel dispenser. For example, for "jumping gun" or "pinching gun", its essence is the interruption and connection of oil flow and the change of the pressure of the entire liquid system. The fuel dispenser must pass the flow interruption test during the type evaluation test, that is, the fuel dispenser After refueling artificially intermittently during the refueling process, the indication error and repeatability should meet the requirements, otherwise production is not allowed. In addition, the country has strict management of fuel dispensers. Before the fuel dispensers leave the factory, the metering control is very strict. After leaving the factory, the fuel dispenser is also included in the measurement supervision system, which reflects the country's great emphasis on measurement instruments. Therefore, the normal "jumping gun" or "pinching gun" during refueling is just a protective function to prevent oil spills during refueling, and will not affect the amount of refueling. All car owners who go to refuel after we understand this knowledge You can rest assured.
