DRAINING SEDIMENT FROM THE FUEL TANK
Shapran Vladimir Nikolaevich 1, Kartukov Alexander Gennadievich 2, Bereznyak Alexander Vasilievich 3
1 Ryazan Higher Airborne Command School (Military Institute) named after Army General V.F. Margelova, Doctor of Technical Sciences, Professor, Professor of the Department of Engines and Electrical Equipment
2 Ryazan Higher Airborne Command School (military institute) named after Army General V.F. Margelova, Candidate of Technical Sciences, Lecturer at the Department of Automotive Service
3 Ryazan Higher Airborne Command School (military institute) named after Army General V.F. Margelova, applicant
annotation
This article describes a special drain device that has been developed and is used to drain a certain amount of fuel from a tank and prevent sediment from accumulating in the fuel tank.
DISCHARGE OF THE SEDIMENT FROM THE FUEL TANK
Shapran Vladimir Nikolaevich 1, Kartukov Alexander Gennadievich 2, Berezniak Alexander Vasilievich 3
1 Ryazan high airborne command school (the military institute) name of the General of the army V. Margelov, doctor of the technical sciences, professor, professor of the engines and electrical equipment department
2 Ryazan high airborne command school (the military institute) name of the General of the army V. Margelov, candidate of the technical sciences, lecturer of the automobile service department
3 Ryazan high airborne command school (the military institute) name of the General of the army V. Margelov, competitor
Abstract
In this article is described designed special owerflow device, used for discharge assigned quantity of the fuel from tank and not-admissions of the accumulation of sediment in fuel tank.
Fuel tanks must have a plug or valve to drain sediment from the tank. The taps often leak, so their use on large-capacity fuel tanks is not advisable. Controlled military tests show that drivers do not always ensure that sludge is regularly drained from tanks for various reasons, or they drain an uncontrolled amount of fuel.
In order to prevent the accumulation of sludge in the tank, as well as to drain a strictly dosed amount of fuel from the tank, a special drain device has been developed (Figure 1a), which has a locking device (Figure 1b).
a) assembled device; b) locking device;
1 – body; 2 – sealed hollow cover; 3 – holes; 4 – hollow spool; 5 – sealed partition; 6,7 – cavities; 8 – fuel tank; 9 – spool plug; 10 – spring; 11 – clamp; 12 – clamp axes; 13,14,15,16,17,18 – radial holes; 19 – air cavity; 20 – internal cavity
Figure 1 – Device for draining sludge from the fuel tank
The device for draining sludge from a fuel tank (Figure 1a) consists of a housing 1, made in the form of a sump, separated from the tank by a sealed hollow lid 2 with holes 3 in the bottom wall, a hollow spool 4, divided inside by a sealed partition 5 into two longitudinal cavities 6 and 7. The housing 1 of the drain device is rigidly attached by welding from below to the fuel tank 8. The spool 4 is located in the cavity of the housing 1 and the fuel tank 8. The cavity of the spool 4 is equipped with a plug 9 on top, which is also the base of the shut-off device.
The locking device (Figure 1b) consists of a gasket 9, a spring 10 and two clamps 11, fixed to the plug 9 using axes 12. The clamps 11, under the action of the spring 10, tend to take a position in which the lower edges of the clamps protrude beyond the limits of the spool 4.
In the spool body 4 there are radial holes 13-18 for draining fuel and filling the body 1 of the drain device with sediment. The sealed hollow cover 2 has a cavity 19 and a hole 3 connecting cavity 19 with cavity 20 of the device body.
The device for draining sludge from the fuel tank works as follows (Figure 2). When filling the fuel tank 8, fuel enters the internal cavity 20 of the device through holes 15-17. Air from cavity 20 of the device is forced out through holes 15 and 18 (when the fuel level increases only through hole 18), cavities 6 and 7 (when the fuel level increases only through cavity 6), holes 13 and 14 (when the fuel level increases only through hole 13 ), into the fuel tank. Displacement of air by fuel will occur until the fuel level exceeds the upper edge of the hole 18. After this, air will be in the device only in the cavity 19 of the sealed hollow cover 2 connected through hole 3 to the cavity 20 of the device, the air pressure in the cavity 19 at the same time will be equal to the fuel pressure in the fuel tank. The cavity 19 and hole 3 in the sealed cover 2 are designed in such a way as to prevent complete displacement of air from it when the car moves over uneven surfaces.
To drain the fuel sludge during routine maintenance and maintenance, the spool 4 is turned out until the latches 11 stop in the cover 2. In this case, the holes 13 and 14 are blocked by the threaded part of the sealed cover 2 and thus the cavities of the fuel tank and the device body are separated. At the same time, fuel sediment flows out through holes 15 and 18 from the body 1 of the device. Since hole 17 will be open to drain sludge earlier than hole 16, draining sludge from cavity 6 will occur earlier than from cavity 7, and filling of cavity 6 will occur earlier than from cavity 7, since the total throughput of holes 14 and 15 is equal to the throughput cavities 7 and holes 16. Draining of fuel from cavity 20 through holes 13-15 and 18 and from cavities 6 and 7 through holes 16 and 17 will be facilitated by the presence of air compressed by a column of fuel in the tank in cavity 19, a sealed partition.
As the fuel level decreases below the edge of hole 13, the flow of fuel into cavity 6 will be reduced, since fuel enters only through hole 18, the throughput of which is significantly less than the throughput of cavity 6. Hole 17, which has a throughput exceeding the throughput of cavity 6, will simultaneously provide air into cavity 20 of the device body, which will ensure normal drainage of sludge from the drain device body through hole 18, cavity 6, hole 17, as well as through hole 15, cavity 7 and hole 16.
a) operation in filling mode; b) operation in drain mode.
Figure 2 - Operation of the drain device
When screwing on spool 4, the cavities of the fuel tank and the device body are connected. Fuel enters cavity 20 of the device body, through holes 13 and 14 of cavities 6 and 7, holes 17,18 and 15,16, respectively. Air from cavity 20 of the device body will be squeezed out through hole 3 into cavity 19 and compressed to a pressure equal to the pressure of the fuel column in the tank, and when the pressures are equalized, air can be forced out through hole 18, cavity 6 and hole 13 into the fuel tank.
Thus, installing the developed drainage device on dual-use vehicles will ensure that only the sludge contained in the drainage device is drained from the tank
Bibliography
- Patrahaltsev N.N. Diesels: system for regulating the initial fuel injection pressure [Text] / N.N. Patrahaltsev, A.A. Savastenko, V.L. Vinogradsky // Automotive industry. -2003. -M. – P.21-23
- Fuel equipment and diesel control systems [Text]: Textbook for universities / L.V. Grekhov, N.A. Ivashchenko, V.A.Markov - ed. 2nd. – M.: Legion-autodata, 2005. – 344 p.
- Buryachko V.R. Car engines. [Text] textbook / V.R. Buryachko, A.V. Hook. SPb. NPICC. 2005. – 292 p.
- Shapran V.N. Engine design. [Text] student allowance for universities / V.N. Shapran, N.L. Puzevich, V.V. Nechaev. – Ryazan: RVAI. – 2009. -121 p.
- Ishkov A.M.. Theory and practice of equipment reliability in the North. [Text] textbook / A.M. Ishkov, M.A. Kuzminov, G.Yu. Zurov. – Yakutsk YaFGU. Ed. SB RAS. – 2004. – 313 p.
As everyone already understood, the valve drains fuel sediment from the tank.
And right now I will tell you how it is connected with, and in general about the meaning of life.
Since the volume of the fuel tank is cubic meters (the wing tank is approximately 7800 liters), air is constantly sucked into it.
That is, you are on the ground (I remind you that the wing tanks are always filled to the maximum, and usually this is until full).
And during the flight, kerosene, naturally, is spent on We pierce the clouds with silver lightning, like Apollo.
And air is sucked in to replace the kerosene.
Air, of course, always contains some amount of water vapor.
And this steam can condense inside the tank. And then flow down the walls, eventually to the lowest point.
And what is at our lowest point? - Right, .
And the pumps begin to drive this water to the engine inlet.
In general, there is nothing particularly terrible about this, since they still capture a little kerosene.
But the thing is that it is very cold at altitude.
And the fuel is cooled to -20 degrees, or even lower.
And here the water seems to freeze a little.
What happens if a lot of water freezes inside the tank?
Probably nothing good.
The pumps might even stop supplying kerosene?
In addition, although at the engine inlet the fuel is heated in a fuel-oil radiator, I still would not really recommend poking it with chunks of ice.
In general, world aviation science has come up with the idea of sometimes draining water from fuel.
And now we'll see how it's done.
There are sludge drain valves at the lowest points of all tank compartments. 
They are also made smartly.
The valve cup is attached directly to the casing panel from the inside. 
And already inside it there is a drain valve itself with a plate spring-loaded from the inside. 
The valve is screwed into the glass using a thread. 
The inside of the glass is equipped with its own shut-off valve, which allows you to change the drain valve without draining the fuel from the tank. The shut-off valve stops the flow of kerosene when the drain valve is unscrewed.
Let's look at the materiel.
This is a typical view of a wing root from below. 
At the bottom left of the photo we see fragments of the landing gear strut. To the right - .
At the top left is the access panel to the inside of the tank.
In the middle are plastic casings for the electrical wiring to the fuel pumps.
Between them - hand-to-hand combat.
Round covers provide access to the fuel pumps. In appearance and method of replacement, they are similar to those already described.
And just between them we see the lowest point of the wing tank drain.
It is from this point that the most water is drained - approximately from 0.5 to 5 liters at a time.
To drain, you need to press the valve plate from below and substitute some container.
Since on the apron it is undesirable to crap all the concrete under the plane with flammable liquid, there are different devices for draining - from the simplest funnels with a built-in poker to various clever designs.
The average in terms of sophistication looks like this: 
From the upper points they drain through a large pipe, and from the lower points through a short one from the ground or from a small stepladder. 
Theoretically, the sludge should be drained before and after each refueling, but since this is hardly feasible in practice, it is usually drained once or three times a day according to calendar maintenance such as Daily check.
Let's remember briefly.
When the plane arrives with cold fuel, and the sludge needs to be drained. 
It happens that the drain valve is frozen inside and/or outside.
The use of force against him would be unjustified because:
1. even if you push it inside, the frozen water will not allow the fuel to leak.
2. and when the fuel finally warms up, it may leak out through the stuck open valve.
3. If you push the valve hard, it happily dislodges the spring ring that holds its back plate, and the valve remains open, flowing down towards you. You plug it with your finger and wait tens of minutes for someone to help you correct the situation. To fix it you have to unscrew the current valve, and you get wet all over as a reward for your perseverance.
4. The rubber band that seals the movable valve plate is very delicate and just wants to get out of the groove and stop sealing the hole.
So it’s better to warm up the fuel before draining.
The maintenance manual offers us several ways to heat the fuel.
This
- infrared heating
(I wonder if there is at least one such installation in Russia?),
- natural heating in a warm hangar
(and how do they imagine towing each Daily check into a hangar and laying there for hours just to warm up the fuel? For example, the Rossiya airline has only TWO seats in the hangar for the entire fleet of more than thirty Airbuses alone. Moreover, these places are always occupied for disassembled aircraft at C-check. Therefore, everywhere and always Daily is carried out mainly on the street),
- refueling with warm fuel
(good idea. That is, in the warm season, I don’t need to do Daily when it’s scheduled, but do all the other work, then be free and ready to work on other planes, and before departure I need to jump from another plane on purpose to drain this and spend at least half an hour draining the sludge, and in winter even this won’t work),
- heating outside the wing with a motor heater
(not bad in theory. Just warm up the whole wing for an hour... well, there are perverts in nature, but they don’t live long)
As you can see, a simple operation, from the point of view of warm Europeans, turns out to be somewhat difficult nuances of real operation.
In particular, therefore, gentlemen, I and... Work on an airplane already takes at least an hour, and more often than not. And during this time, with pumps running, kerosene may well have time to cross zero.
Now let's see how the sediment is drained from the central tank.
To access its drain valves, you need to open the hatches on the belly fairing from below, between the air conditioning packs and the niche of the main landing gear. 
This is just one of them, yeah :) 
There we immediately see: 
- bottom left - handle for opening / closing the landing gear niche flap on the ground.
- at the top right - a lamp illuminating the contents of the hatch. By the way, these hatches contain hydraulic system units.
- at the top center is the drain valve itself. 
This is exactly the valve of a healthy person - dry and sparkling with a blue rubber band.
And the adjacent hatch is inhabited by a smoker valve. 
In the light of a flashlight, drops of kerosene shine well, seeping into the gap between the loosely closed plate and the valve body.
Since the space inside these hatches is limited, and there are various devices near the valves that only interfere with pressing the funnel evenly, draining the sediment from these valves is more difficult than simply poking the wing valve from below. Therefore, the valve plates move sideways more easily, and after removing the drain device, it is necessary to check that there is no fuel leakage.
This can be even more difficult because there is usually almost no fuel in the central tank after a flight. And if the valve is not closed tightly, then kerosene may leak out just a little bit. But before departure, after refueling six tons, the leak will appear in all its glory :)
In this case I was lucky.
The rubber on the plate remained in place, it was not chewed, damaged, or carried away inside the tank.
Only the plate moved a little. And simply by centering it with a screwdriver, we managed to eliminate the leakage.
And finally, a little about kerosene.
To prevent fuel vapor from accumulating, these small compartments are ventilated.
Through small gaps near the air outlet pipe from the air conditioning pack. 
When the pack is operating, a strong stream of air constantly blows from it.
And due to ejection, it sucks air into itself from the mentioned cracks. 
And takes it out into nature.
This is roughly how kerosene is drained.
and now...
only by train!
11 (7.2 % )
No special tool required.
The following spare parts must be purchased:
- Injection engines: 2 copper spacers.
- Fuel filter for the corresponding engine. When purchasing, please indicate the year of manufacture and model of the car.
Diesel engine
Draining sediment/replacing the fuel filter
A suitable vessel is required to collect the sludge.
Draining sludge
- Loosen the drain bolt by hand approximately one turn.
- Pump with a hand pump (about 7 times) until unmixed diesel fuel comes out.
- Tighten the sediment removal bolt by hand.
- After draining the sediment, air must be removed from the fuel system.
Replacing the filter
- Loosen the tension bolt -arrow- of the fuel filter clamp.
- Unscrew the fuel filter from the holder using a special wrench and remove it.
- If equipped, unscrew the sediment level sensor using water pump pliers, insert and screw it into the new filter.
- Fill the filter to the brim with diesel fuel and screw it on by hand.
- Remove air from the fuel system.
- After a test drive, check the fuel system for leaks.
Removing air from the fuel system
- Pump with a hand pump until there are no air bubbles in the fuel protruding from the bleeder bolt.
- Tighten the bolt while pressing the hand pump.
- Pump with a hand pump (about 15 times) until you feel resistance when pressing.
- Turn on the preheat and then start the engine.
- If the engine does not start, bleeding should be repeated.
- Visually check the fuel system for leaks, especially the fuel filter connections.
Carburetor engines
The fuel line is located in the engine compartment in the fuel supply line. To disconnect the supply and return pipelines, you will need 2 clamps. You can use two clamps.
- Clamp the supply and return lines before and after the fuel filter with clamps.
- Loosen the hose clamps and disconnect the pipes from the filter.
Installation
Engines with injection system
When removing the fuel filter, a large amount of fuel will leak out and a suitable container is required to catch it. To shut off the fuel lines, you will need two rubber plugs.
- Place a suitable container under the fuel filter.
- Allow the fuel to drain into the container.
- Unscrew the upper connecting bolt and remove the fuel line with 2 gaskets.
- Release the fuel filter from its mounting.
Each power plant of a car, regardless of what fuel the car runs on, works by converting the energy that is released during the combustion of the fuel-air mixture into energy that forces the crankshaft to move. Fuel is supplied to the cylinders through a complex system - the power supply system. Since the engine and associated components are already subject to excessive loads, it is necessary to minimize the impact of external factors on the totality of systems. In particular, it is necessary to purify the fuel, that is, remove from it all compounds that can harm the “heart” of the car. This is why you need a sediment filter.
How does a settling filter work?
The settling filter is responsible for the preliminary (rough) cleaning of the fuel from foreign particles larger than 0.5 mm in size. There is a hole in the filter cover where fuel is supplied. Inside the body of the device - the glass - there is a central rod, inside of which there is a hole through which purified fuel is discharged. The housing has a drainage device, which is closed with a special plug. In addition, the settling filter is equipped with devices such as a reflector and a damper. They form an integral structure with the lid. The damper is installed at the bottom of the glass. The filter also has a mesh filter element located on the main rod; inside it lies a material that absorbs moisture. This filter element can be removed. The sediment filter is designed in such a way as to clean the fuel as efficiently as possible. As with any element,
The settling filter has its disadvantages:
- servicing such a device is quite difficult;
The mesh filter element does not clean the fuel well;
The settled mechanical impurities are washed out.
Next, the fuel goes to the mesh filter element, which is located on the main rod. After this, the fuel goes into a cavity with moisture-absorbing material, which is located inside the mesh filter. After passing through both filters, there is no water or small impurities of a mechanical nature left in the fuel. Already clean fuel enters through the hole in the main rod. The sludge must be drained through a special hole in the housing, which is constantly closed with a special drain plug. It can be removed to clean the filter. Since the settling filter is equipped with additional moisture-absorbing material, no moisture remains in the fuel, which greatly increases its quality. The better and more efficiently the sediment filter does its job, the longer the engine will last.
Sump filter maintenance
Before moving on to servicing the system, you need to determine where the settling filter is located. Whatever the make and model of the car, the sediment filter will always be located near the fuel tank. To find it accurately, you just need to follow the fuel pipes that come from the tank. Using them you are guaranteed to find a filter. Maintenance of the sediment filter involves regularly draining the sludge. To do this, you need:
1) Thoroughly clean the outer surface of the filter from dust and dirt;
2) Unscrew the drain plug and drain the sediment from the filter (the signal that the plug can be closed is the release of clean fuel).
This procedure must be carried out after the engine has operated for a full 60 hours. The filter must be washed every 960 working hours. You need to perform the following sequence of actions:
1) Close the fuel tank tap;
2) Clean the outer surface of the filter from dust and dirt;
3) Unscrew the bolts, remove the housing and pressure ring;
4) Unscrew the filter element and remove the distributor;
5)
Rinse the filter element and distributor in diesel fuel, after which they can be returned to their place, and the filter element must be screwed in with a key until it stops;
6) The filter-sump filter glass needs to be washed, and after checking the integrity of the gasket, it can be returned to its place. After the filter is washed, the fuel system can be filled with fuel.
Replacing the sediment filter
Before replacing the unit, you need to find out why it is being replaced at all. If you do not change the sediment filter in time, the fuel channels will become clogged, causing the power plant to operate intermittently. Plus, large mechanical impurities that are retained by the sediment filter act as abrasives that can harm some carburetor elements.
If your car's power supply system is injection, then the presence of certain impurities in gasoline is extremely undesirable. In such a system, gasoline is supplied to the cylinders in a certain dose and under a certain pressure. Fuel is dosed by an injector. Its design includes precision pairs - parts machined with high precision that interact with each other. The abrasive properties of impurities in gasoline can either damage the surface of these pairs or cause these parts to jam, causing the injector to fail.
The most demanding fuel purity is the diesel engine power system. It is special in that there are precision vapors only in the injector and the injection pump, therefore dangerous impurities in the fuel can cause failure of both the injector and the injection pump. That is why the power system includes a fuel filter and more than one.
To complete the work you will need:
- a set of keys and screwdrivers;
Protective gloves;
A container into which the fuel in the filter will be drained;
Compressor or pump.
The coarse fuel filter of the carburetor system is made as follows. First you need to remove the mesh located on the fuel neck. If it is excessively dirty, it must be washed in gasoline and blown out with compressed air. You also need to clean the mesh on the fuel intake, but first you need to remove it from the tank. The mesh that is located on the carburetor inlet fitting can be cleaned only after the fitting is unscrewed.
If the car has an injection power system, then you can only get to the coarse filter through a special hatch installed in the tank. For diesel cars, the sediment filter must be disconnected from the power system, disassembled using keys, the fuel contained in the filter must be drained into a previously prepared container, and the filter itself must be thoroughly washed and purged. If there is a filter element, it must be replaced.
After you replace or wash, be sure to check the condition of all fasteners. Everything needs to be done so that in no place where the filter is connected to the fuel line does air get sucked in or the fuel itself does not leak.
Purification of gasoline or diesel fuel is extremely important to ensure normal and stable operation of the entire vehicle power system.
