Field of the Invention
[0001] The present invention relates to a filter and non-return valve device for use in
a fuel delivery unit. The invention further relates to a fuel delivery unit comprising
such a device, and methods for installation and maintenance of the device.
Background of the Invention
[0002] A fuel delivery unit typically comprises one or more storage tanks and a pump unit
which generally comprises a housing that holds a pump, a pump motor, metering equipment
and one or more delivery nozzles. The storage tanks are often located under ground
and thus need to be connected to the pump unit by means of conduits.
[0003] The conduits connecting the pump unit and the storage tanks are generally provided
with non-return valves which prevent fuel that has been pumped up from the storage
tank from pouring back into the storage tank when the pump is inactive. It is important
to have liquid, in this case fuel, in the system at all times for the pump to function
properly. Introduction of air in the upper part of the system could cause the pump
to cease functioning, especially if the vertical distance between the pump and the
storage tank is large. The preservation of fuel in the conduit also decreases the
delivery time when filling up a vehicle, since the fuel will not have to be pumped
all the way from the storage tank each time a delivery is initiated.
[0004] As shown in Fig 1, the non-return valve was originally arranged near the storage
tank, under ground, thus effectively preventing the fuel in the conduit from returning
to the storage tank. However, this arrangement was prohibited for environmental reasons,
since the non-return valve would, in case there was a leak in the conduit, allow the
fuel in the conduit to leak out into the ground instead of pouring back into the storage
tank. This is also the reason why the pump is often placed above ground.
[0005] US 2 922 288 A, according to the preamble of claim 1, discloses a fuel delivery device
having a filter, a first non-return valve downstream the filter, and a second non-return
valve upstream the filter.
[0006] Instead today, as shown in Fig 2, the non-return valve is placed just upstream from
the pump, above ground level, inside the housing. Upstream from the non-return valve,
a filter is generally arranged, in order to filter the fuel so as to remove e.g. solid
particles which may damage the pump, the metering equipment or the vehicle being fueled.
Such filters need regular maintenance or replacement.
[0007] In order to access the filter, the fuel in the conduit between the non-return valve
and the filter needs to be removed in order to prevent fuel from spilling out and
polluting the environment or causing a risk of explosion. This can be done by e.g.
opening or removing the non-return valve and thus eliminating the vacuum that keeps
the fuel from returning to the storage tank. The fuel then flows back to the storage
tank. After the filter maintenance is completed, the fuel has to be pumped back all
the way from the storage tank. This operation is time consuming and works against
minimizing the maintenance downtime of a fuel delivery unit.
[0008] Hence there is a need for a device and method which enable more efficient filter
maintenance in a fuel delivery unit.
Summary of the Invention
[0009] It is therefore an objective of the present invention to provide devices and methods
for enabling e.g. maintenance access to a filter in a fuel delivery unit, without
losing or releasing all of the fuel that has already been pumped up into the conduit.
[0010] This and other objectives are achieved wholly or partially by a device comprising
the features of any one of the enclosed independent claims 1, 22 or 27, and by a method
comprising the steps of any one of independent claims 28 or 29. Preferred embodiments
are set forth in the enclosed dependent claims and in the following description.
[0011] According to the invention, a device for a fuel delivery unit is provided. The device
comprises a channel for conducting a fuel flow, a filter unit arranged for filtering
the fuel flow and a first non-return valve arranged downstream of the filter unit,
said first non-return valve allowing the fuel to flow freely in a first direction
but preventing the fuel from flowing in a second direction. The device further comprises
a second non-return valve arranged upstream of said filter unit, allowing the fuel
to flow freely at a first flow rate in the first direction but substantially preventing
the fuel from flowing in the second direction. The device further comprises leakage
means for allowing the fuel to flow at a second flow rate in the second direction,
from a downstream side to an upstream side of the second non-return valve.
[0012] The channel is typically a conduit, pipe, hose or other type of tubular structure
or hollow body that is suitable for conducting a fuel flow. The second direction is
essentially opposite to the first direction. The "downstream side" of a non-return
valve is to be understood as the downstream side of the main (first) flow direction.
Analogously, the "upstream side" is to be understood as the upstream side in the main
flow direction.
[0013] While it is known to arrange the first non-return valve downstream of the filter,
the arrangement of the second non-return valve provides advantages in that fuel is
allowed to flow backwards, past or through the second non-return valve at a rate which
is low enough to allow an operator to e.g. replace the filter unit before all of the
fuel remaining in the channel has flowed back towards the storage tank. Thus, some
fuel is removed from the channel, so that the filter may be replaced essentially without
spillage, but not so much as to introduce an amount of air in the conduits that could
hamper the function of the pump.
[0014] Preferably, the channel may comprise an essentially tubular, flexible structure.
Such a flexible structure makes assembly and disassembly more convenient.
[0015] The device may further comprise coupling means, adapted for detachably interconnecting
any two of: an end of said channel, the filter unit, the first non-return valve and
the second non-return valve. Such coupling means also provide for easy assembly and
disassembly for e.g. maintenance purposes.
[0016] The coupling means may be integrated with at least one of the channel, the first
non-return valve, the filter unit and the second non-return valve. This may provide
for a compact design and a reduced amounts of parts to keep in storage and to assemble/disassemble.
Preferably, the coupling means are adapted for detachably coupling one of the first
non-return valve and the filter unit to a downstream element, such as a pump, conduit
or other component within the fuel delivery unit.
[0017] The first non-return valve and the filter unit are advantageously detachably arranged,
adjacent each other, at a first end of the channel. The first non-return valve and
the filter unit may even be integrated or detachably integrated with each other. The
first non-return valve may also be provided with means for regulating it between an
open and a closed state. This would allow an operator to open the first non-return
valve in order to let some fuel flow back through the second non-return valve before
the channel is disconnected, so as to minimize the risk of spillage when disconnecting
the channel.
[0018] The second non-return valve is advantageously arranged at a second end of the channel,
so that the channel may lead a flow from the second non-return valve to the filter
unit and the first non-return valve. The first non-return valve is preferably arranged
at a vertically higher level than the second non-return valve, so as to prevent fuel
from spilling from the channel when disconnecting the channel from the first non-return
valve.
[0019] By arranging the channel between the first and second non-return valves, the channel
may be disconnected from the first non-return valve while replacing the filter so
that the fuel remaining in the channel slowly flows back through the second non-return
valve, while the filter is replaced. By providing the channel with a flexible section
that is arranged between said first and second non-return valves, the channel may
be easily displaced during maintenance operations.
[0020] Preferably, the second flow rate is substantially lower than the first flow rate.
This may be achieved by adapting the leakage means for allowing a predetermined amount
of fuel to flow in the second direction during a predetermined time period. For example,
the second non-return valve may be at least partly permeable, the leakage means may
be formed by a hole in the second non-return valve, or the leakage means may comprise
a by-pass channel leading the fuel past the second non-return valve.
[0021] In a preferred embodiment, the device is arranged in a fuel delivery unit comprising
a pump for providing the fuel flow and a fuel source from which the fuel is drawn.
The pump may be arranged downstream of the first non-return valve, while the fuel
source may be arranged upstream of the second non-return valve.
[0022] The present invention also comprises a kit of parts for providing a device for a
fuel delivery unit. This kit of parts may comprise a channel adapted for conducting
a fuel flow, a filter unit adapted to be arranged for filtering the fuel flow and
a first non-return valve adapted to be arranged downstream of said filter unit, so
that the first non-return valve will allow the fuel to flow freely in a first direction
but prevent the fuel from flowing in a second direction. The kit may further comprise
a second non-return valve adapted to be arranged upstream of said filter unit, in
order to allow the fuel to flow freely at a first flow rate in the first direction
but to substantially prevent the fuel from flowing in the second direction. Finally,
the kit may comprise leakage means adapted for allowing the fuel to flow at a second
flow rate in the second direction, from a downstream side to an upstream side of the
second non-return valve. The kit of parts may be assembled into a device such as the
one described above.
[0023] The present invention further comprises a method for providing a filter unit in a
fuel delivery unit. The method comprises a number of steps, one of which is to connect
a second non-return valve to a fuel source in order to allow fuel to flow freely at
a first flow rate in a first direction, while the fuel is substantially prevented
from flowing in a second direction. Another step is to provide leakage means for allowing
the fuel to flow at a second flow rate in the second direction, from a downstream
side to an upstream side of the second non-return valve. Yet another step is to connect
a channel to a downstream side of said second non-return valve, in order to conduct
the fuel from the fuel source. A further step is to arrange a filter unit in the channel,
in order to filter the fuel conducted in the channel. A first non-return valve is
connected on a downstream side of said filter, in order to allow the fuel to flow
freely in the first direction but prevent the fuel from flowing in the second direction.
A downstream side of said first non-return valve is connected to a fuel drain. The
fuel drain may be a conduit or a pipe that serves as a continuation of the conduit
from the storage tank to the delivery nozzles. It may also be a pump or any other
type of equipment which is connected downstream of the first non-return valve.
[0024] This method provides a structure in a fuel delivery unit, which allows for easy and
spillage-free replacement of a filter unit. The above described steps do not need
to be performed in the order recited.
[0025] Furthermore, a method for replacing a filter or filter unit that is positioned to
filter a fuel flow conducted in a channel of a fuel delivery unit is provided. The
method comprises the steps of disconnecting a first end of a channel from one of a
fuel drain, a filter unit and a first non-return valve, and allowing fuel remaining
in the channel to flow through a leakage means, in a second direction, from a downstream
side to an upstream side of a second non-return valve.
[0026] While the fuel is flowing in the second direction, the steps of removing the filter
or filter unit, inserting a new or restored filter or filter unit, and connecting
the first end of the channel to said one of a fuel drain, a filter unit and a first
non-return valve are performed. Through this method, the filter or filter unit may
be replaced without total loss of all the fuel present in the channel or in a conduit
from a storage tank. The method may also comprise a step of opening the first non-return
valve prior to disconnecting the first end. This would further reduce the risk of
spillage when disconnecting the channel.
[0027] A non-return valve for use in a fuel delivery unit, for example as the second return
valve of the invention, may comprise a passage for conducting a fluid in a first direction
and closure means for substantially closing said passage from conducting fuel in a
second direction. The closure means may be moveable between a closed and an open position
based on the direction of the flow through the non-return valve. The non-return valve
further comprises leakage means for providing a flow in the second direction, from
a downstream side to an upstream side of the closure means. Such leakage means enables
the non-return valve to be used as the second non-return valve described above. The
leakage means may comprise for example a permeable element or a hole in the closure
means for allowing fuel to flow in the second direction through the non-return valve.
The leakage means may also comprise a by-pass channel for allowing the flow in the
second direction to flow past said closure means.
[0028] The non-return valve may be of may different types, as is described below. One appropriate
non-return valve may be a dual flap check valve, but other types of non-return valves
may also be used.
[0029] A filter unit for use in a fuel delivery unit such as the one described above may
comprise a filter and a non-return valve, which is arranged at the downstream side
of the filter or the filter unit and which allows fuel to flow freely in a first direction
but which prevents the fuel from flowing in a second direction through the filter.
From an assembly/disassembly point-of-view, it is advantageous to integrate the filter
and the non-return valve into one housing.
[0030] The non-return valve may be of different types, as is described below. One appropriate
non-return valve is a dual flap check valve, but other types of non-return valves
may also be used. Finally, the filter unit may comprise means for regulating the non-return
valve between an open and a closed state, so that fuel present in the channel may
be removed prior to replacing the filter.
Brief Description of the Drawings
[0031] The invention will be described in more detail with reference to the appended schematic
drawings, which show examples of presently preferred embodiments of the invention
and its constituents.
Fig 1 is a schematic view of a first prior art fuel delivery system.
Fig 2 is a schematic view of a second prior art fuel delivery system.
Fig 3 is a schematic view of a fuel delivery system according to the invention.
Fig 4 is a schematic view of a an enlarged part of the fuel delivery unit in Fig 3.
Fig 5 is a perspective view of an embodiment of a device for a fuel delivery unit.
Fig 6 is a perspective view of a filter unit and a first non-return valve of the embodiment
shown in Fig 5.
Fig 7 is a perspective side view of the filter unit and first non-return valve of
the embodiment shown in Fig 5.
Fig 8 is a perspective view of a second non-return valve.
Fig 9 is a perspective top view of the second non-return valve.
Fig 10 is a detailed perspective view of a device according to an embodiment of the
invention.
Fig 11 is a side view of the device shown in Fig 10.
Fig 12a-e are schematic views of examples of a filter unit and a first non-return
valve to be used in the invention.
Fig 13a-c are schematic views of examples of a non-return valve with leakage means
which may be used as the second non-return valve.
Description of Preferred Embodiments
[0032] Fig 1 and 2 show schematic diagrams of prior art fuel delivery systems, which have
been discussed above.
[0033] Fig 3 is a schematic diagram of a fuel delivery system according to the invention.
The fuel delivery system operates to transport fuel from a storage tank 2 to a delivery
nozzle 18, for delivering fuel to vehicles such as e.g. automobiles, motorcycles,
boats or aircraft. The storage tank 2 can typically be placed below the ground level
0 on which the fuel delivery unit 1 is arranged, e.g. buried or just placed on a lower
level or story.
[0034] The storage tank 2 can be connected to the fuel delivery unit 1 via at least one
conduit. The fuel can be caused to flow from the storage tank 2 through the conduit
by means of a pump 5, which can be arranged within the fuel delivery unit 1. Such
a pump can be e.g. a vacuum pump, that generates a negative pressure, which draws
the fuel from the storage tank 2 and causes it to move in the flow direction F as
indicated in Fig 3. The delivery nozzle 18 can be arranged downstream of the pump
5.
[0035] In the conduit, a second non-return valve 7 is arranged, which operates to allow
the fuel to move in the flow direction F, but which prevents the fuel from moving
against the flow direction F. The second non-return valve 7 may be any type of non-return
or check valve, such as e.g. of ball type, flap type, disk type, ring type, membrane
type. The non-return valve may also be a swing check valve, a piston or lift check
valve or, as in the embodiment described herein, a dual flap check valve. The non-return
valve may or may not be spring loaded. However, at this second non-return valve 7
a leakage means 13, such as e.g. a hole, a by-pass channel or a membrane is arranged,
so that fuel may flow at a low rate, against the flow direction F, past or through
the second non-return valve.
[0036] Downstream of the second non-return valve, a filter unit 6 is arranged for filtering
the fuel flow so as to remove particles or solids that may damage the pump 5, the
vehicle or any other parts of the fuel delivery unit 1. The filter unit comprises
a filter 8 (Fig 4), which may be removable from the filter unit 6, e.g. so that it
can be replaced or maintained. The filter 8 may be any type of filter or membrane
that is suitable for filtering fuel of the type delivered by the system. Such filters
may be made from e.g. fabric, non-woven, paper, polymers or other suitable filter
materials.
[0037] Downstream of the filter unit and upstream of the pump 5 a first non-return valve
4 is arranged, which allows the fuel to move in the flow direction F but which prevents
the fuel from moving against the flow direction F. The first non-return valve 4 may
be of essentially the same type as the second non-return valve 7, or of a different
type or size.
[0038] In addition to the above mentioned equipment, further equipment such as fuel blending
means, metering equipment and payment equipment can be arranged in the fuel delivery
unit.
[0039] The leakage means 13 operates to facilitate maintenance of the filter unit 6 by allowing
fuel to flow back into the storage tank, past or through the second non-return valve,
at a low enough rate, so that the filter unit may be maintained and the filter 8 replaced,
before all the fuel present in the conduit 3 has flowed back to the storage tank 2.
Thus, it will take less time to refill the conduit, and thereby the maintenance downtime
of the fuel delivery unit 1 will be reduced.
[0040] Fig 4 is a schematic diagram of a device for a fuel delivery unit according to the
invention. The device forms a part or a continuation of the conduit 3 from the storage
tank 2 to the pump 5. The device comprises the two non-return valves 4, 7, the leakage
means 13 and the filter unit 6 as described above. Between the filter unit 6 and the
second non-return valve 7 a channel 9 is arranged.
[0041] The channel 9 may be any suitable conduit, pipe, hose, tubular structure or other
hollow body that is capable of conveying a fluid such as fuel. The channel 9 can have
a first end and a second end, at which first and second openings are provided. Generally,
the first end of the channel 9 is situated on a vertically higher level than the second
end of the channel, so that fluid present in the channel 9 needs to be propelled in
order to move in a first direction, but may flow by means of gravity in the second
direction.
[0042] The second non-return valve 7 is arranged at the second end of the channel 9, which
is connected to the fuel source 11, e.g. the incoming part of the fuel conduit 3.
The first non-return valve 4 is arranged at the first end of the channel 9, which
is connected to a fuel drain 10, i.e. for example a conduit or a pump to which the
fuel goes after having passed the first non-return valve.
[0043] The channel 9 and/or the non-return valves 4, 7 is coupled to the fuel source 11
and fuel drain 10 by coupling means 12 (Fig 6). These coupling means may be any sort
of coupling or connection device that is suitable for providing a sealed and preferably
detachable connection between the channel 9, its non-return valves 4, 7, filter unit
6 and the rest of the conduit 3 via the fuel source 11 and fuel drain 10. Thus, the
coupling means 12 can be provided on the channel, the non-return valves as well as
the filter unit, for coupling these components together and for coupling with the
surrounding equipment such as the fuel source 11 and fuel drain 10. The coupling means
comprise, but are not limited to, threaded fittings, bolted fittings, flange couplings,
bayonet couplings, cam action couplers, bulkhead fittings, clamp fittings etc.
[0044] Fig 5 is a schematic view of an embodiment of a device for a fuel delivery unit according
to the invention. In this embodiment, the channel 9 is a flexible pipe or hose. This
can be advantageous since it will be easy to disconnect one end of the channel in
order to remove the filter unit 6 for maintenance, while the other end near the second
non-return valve 7 remains connected to the fuel source 11.
[0045] Fig 6 is a schematic perspective view of a filter unit and a first non-return valve
of the embodiment shown in Fig 5. In this embodiment, the filter unit and the first
non-return valve are integrated into one housing 20, which in turn is connected to
an end flange 22 of the channel 9. Fig 6 shows the first non-return valve 4 with its
closure means 14 in a closed state. The filter 8 is seen as a protrusion on the opposite,
upstream side of the non-return valve 4. The filter according to this embodiment protrudes
into the channel 9. The filter could also remain completely outside the channel or
more or less be housed in the filter unit 6 or an extension thereof (not shown), so
that the filter does not protrude into the channel 9. Fig 6 shows coupling means 12,
of a slightly different type than those used in connection with the second non-return
valve shown in Fig 8 and 9. Fig 6 also shows a turning device 23, which operates to
open the first non-return valve 4, as will be explained below. This turning device
23 provides a means for regulating, controlling or switching the non-return valve
between an open and a closed state. The means 23 may take on any form which enables
the valve to be regulated between its two states.
[0046] Preferably, the coupling means 12 of the first non-return valve are of a type which
is easily detachable, so that this end of the channel may be easily disconnected from
the fuel drain 10 in order to enable filter maintenance.
[0047] Fig 7 is a schematic side view of the filter unit and first non-return valve shown
in Fig 6. The housing 20 which incorporates the filter unit 6 and the first non-return
valve is shown more clearly.
[0048] The filter unit/non-return valve 4 shown in Fig 6 and 7 is adapted for being permanently
connected to the fuel drain 10, while the channel 9 with its flange 22 is detachably
connected to the filter unit/non-return valve.
[0049] Fig 8 is a schematic perspective view of the second non-return valve 7. The non-return
valve shown in Fig 8 is also a dual flap check valve, having a housing 19 in which
the non-return valve itself, including its closure means 14, is located. In Fig 8,
the closure means are in their open state. The housing 19 also comprises coupling
means 12, which in Fig 8 are shown as holes or bolt fittings on the housing 19 of
the non-return valve.
[0050] Fig 9 is a schematic top view of the second non-return valve 7. The housing 19 is
shown having six holes 12c for bolts by which the valve is fitted to the fuel source
11 and/or the channel 9. In Fig 9, the closure means 14 are shown in their closed
position. Leakage means 13 are shown as holes in the flaps.
[0051] Fig 10 and 11 show a detailed view of the device according to another embodiment
of the invention. In the embodiment shown, the first non-return valve 4 is integrated
with the filter unit 6 in a housing 20, and the filter 8 is removable from the housing
20. Coupling means are shown as bolts 12a which are to be arranged in holes 12c and
fixated with nuts 12b. Plates 12d operate as to fixate the channel end flange 22 at
the first en d 9a of the channel 9 to the housing 20. The channel 9 of Fig 10 is provided
as a flexible pipe having end flanges 22 at both ends. The end flange 22 at the second
end 9b is fastened to the housing 19 in a similar manner as the end flange at the
first end 9a. Fig 10 and 11 also show a valve socket 21 and the closure means 14 of
the second non-return valve 7. Gaskets 24 are provided between the first channel end
9a and the filter 8 as well as between the housing 20 and the fuel drain 11 and between
the second channel end 9b and the valve 7.
[0052] Fig 12a-e are schematic diagrams of examples of a filter unit 6 and a first non-return
valve 4 to be used in the invention.
[0053] In Fig 12a there is shown a filter unit with a first non-return valve which principally
resembles the one shown in Fig 8 and 9, in that the filter unit 6 and the first non-return
valve 4 are integrated into one housing. The channel with its coupling means 12 in
the form of a flange 22 is also schematically shown, as well as the fuel drain 10
with its coupling means 12. The filter/non-return valve unit 4, 6 has two separate
sets of coupling means for coupling with the channel 9 and the fuel drain 10, respectively.
It is however possible to provide coupling means on the filter/non-return valve unit
4, 6, which connects with both the channel 9 and the fuel drain 10 simultaneously.
[0054] Fig 12b discloses a variant, in which the filter unit 6 and the non return valve
4 are provided as separate elements but are joined together by the coupling means.
Here, just like in Fig 12a above, it is possible to use one coupling mechanism to
lock all four parts 4, 6, 9, 10 together simultaneously.
[0055] Fig 12c shows another variant, where the filter unit 6 constitutes a housing having
the coupling means, and where the non-return valve 4 is fitted in an appropriate manner
and held in place by coupling means for coupling it with the filter unit 6. The valve
in this embodiment may also be held in place by virtue of the fuel drain 10 (not shown)
being coupled to the filter unit 6, thereby squeezing or fixating the valve as well.
[0056] Fig 12d shows yet another variant, where the relationship between the filter unit
6 and the non-return valve 4 is reversed: the filter unit is fitted into the housing
of the valve and held in place when the valve housing is connected to the channel
9.
[0057] Finally, Fig 12e illustrates still another variant where both the filter unit 6 and
the non-return valve 4 are fitted into a space in the joint between the channel 9
and the fuel drain 10. The filter unit 6 and the non-return valve 4 are thus held
in place by e.g. flanges, protrusions, indentations or recesses in the joint between
the channel 9 and fuel drain 10.
[0058] From Fig 12a-e it is clear that there are several different ways of connecting the
channel, the filter unit, the first non-return valve and the fuel drain.
[0059] It can be advantageous to connect the first non-return valve 4 to the fuel drain
10 in a more permanent way, while making the connection between on one hand the channel
9 or the filter unit 6 and, on the other hand, the non-return valve 4, more easily
detachable. The reason why this may be advantageous is that the non-return valve may
prevent fuel remaining in the fuel drain 10 from flowing back causing spillage when
the channel 9 and/or the filter unit 6 is removed.
[0060] Fig 13a-c are schematic diagrams of examples of non-return valves to be used as the
second non-return valve in the invention.
[0061] Fig 13a shows how the leakage means 13 are provided as holes in the flaps 14 of the
dual flap check valve. The leakage means may also be provided as an intentional "imperfection"
or "misfit" in the edge of a flap 14, which enables fluid to pass the valve at a lower
rate when it is closed.
[0062] As is shown in Fig 13b, the leakage means 13 may also be e.g. a by-pass channel,
which is arranged so as to lead fluid past the closure means 14. Such a by-pass channel
may e.g. be arranged in the housing 19 or in the valve socket 21.
[0063] Fig 13c shows another option, in which leakage means are provided by making the flap
14 or part thereof permeable, e.g. by providing pores or small holes in its surface.
[0064] In any case, the leakage means should be dimensioned so that they allow a reverse
flow rate past or through the second non-return valve 7, that is low enough so that
the channel may be disconnected from the fuel drain 10, the filter replaced and the
channel reconnected in less time than it takes for the fuel that is present in the
channel when the channel is disconnected to flow back past or through the second non-return
valve 7. The dimensioning of the leakage means is believed to be within the capability
of the skilled person.
[0065] Finally the leakage means can also comprise means for manually opening the closure
means 14 of the non-return valve 7, such as e.g. those described in connection with
Fig 6 and Fig 7 above and referred to as 23.
[0066] The channel 9, second and first non-return valves 7, 4 and filter unit 6 may advantageously
be fitted into a fuel delivery unit, especially between the incoming conduit 3 from
the storage tank and the pump 5 which provides the vacuum for generating the fuel
flow.
[0067] A method of installing a detachable filter unit in a fuel delivery unit comprises
a first step of arranging a second non-return valve 7 at a conduit of a fuel source
11, in order to allow fuel to flow freely at a first flow rate in a first direction,
while the fuel is substantially prevented from flowing in a second direction. The
valve 7 may be coupled to the fuel source 11 by means of complementary coupling means
12 provided on the fuel source 11 and on the valve 7.
[0068] The step of providing the second non-return valve may comprise the step of providing
a leakage means for allowing the fuel to flow at a second flow rate in the second
direction, past or through the second non-return valve. The leakage means may also
be provided in a separate step.
[0069] A further step comprises connecting a second opening of a channel 9 to a downstream
side of said second non-return valve 7, in order to conduct the fuel from the conduit
of the fuel source 11. The channel 9 can be coupled to the valve using coupling means
12 on the valve and on the channel. It is also possible to couple the valve 7 and
the channel 9 to the fuel source 11 in one step, using e.g. a set of locking means
which couples all three components in a single step.
[0070] Yet another step comprises detachably arranging a filter unit 6 in, or at a first
end of, the channel in order to filter the fuel conducted in the channel. The filter
may e.g. be arranged according to any of the arrangements suggested above.
[0071] Another step comprises arranging a first non-return valve 4 on a downstream side
of said filter, in order to allow the fuel to flow freely in the first direction but
prevent the fuel from flowing in the second direction. The valve 4 may be arranged
according to any of the arrangements suggested above.
[0072] A final step comprises connecting a downstream side of the first non-return valve
4 to a fuel drain conduit 10.
[0073] It is obvious that the steps do not need to be performed in the order set forth above.
For example, it is possible to install the device in the fuel delivery unit 1 in the
reverse order or to assemble the device comprising the two valves, the filter and
the channel second and then install it in the fuel delivery unit 1.
[0074] The device provided herein enables a method for replacing a filter unit in a fuel
delivery unit according to the following.
[0075] As a first step, a channel 9 is disconnected from its connection to a fuel drain
10. The disconnecting of the channel may comprise disconnecting the coupling means
of any component which is arranged at that end of the channel, such as a valve 4 or
a filter unit 6.
[0076] When the channel 9 is disconnected, fuel remaining in the channel is allowed to slowly
flow in a direction opposite the normal flow direction F through a leaking means,
past or through a second non-return valve 7.
[0077] While the fuel is flowing past or through the non-return valve 7, the filter unit
is removed from the channel and a new or restored filter unit is inserted, after which
the channel 9 is again connected to the fuel drain 10. The operations of removing
and replacing the filter and reconnecting the channel 9 should take less time than
it takes for the fuel present in the channel to drain completely back past or through
the second non-return valve 7 through the leakage means 13. This is made possible
by providing the appropriate dimensions of the leakage means 13.
[0078] The turning device 23 provided on the first non-return valve may advantageously be
used to open the first non-return valve prior to disconnecting the channel for filter
maintenance. When the valve is opened, fuel may flow back through the first non-return
valve and through the leakage means at the second non-return valve, so that fuel remaining
above the filter is removed, thereby further reducing the risk of spillage.
[0079] It is apparent to the skilled person that the embodiments described above may be
combined and varied within the scope of the invention. For example, it is possible
to combine different valve types with the different types of leakage means described
above. The coupling means and their arrangement on the different parts are other aspects
which provide for endless possibilities of variation.
[0080] It should furthermore be understood that the invention can also be applied to systems
comprising a plurality of storage tanks, conduits, fuel delivery units etc.
Reference numbers |
F |
Flow direction |
P |
Pump |
0 |
Ground level |
1 |
Fuel delivery unit |
2 |
Storage tank |
3 |
Fuel conduit |
4 |
First non-return valve |
5 |
Pump |
6 |
Filter unit |
7 |
Second non-return valve |
8 |
Filter |
9 |
Channel |
10 |
Fuel drain |
11 |
Fuel source |
12 |
Coupling means |
13 |
Leakage means |
14 |
Closure means |
15 |
|
16 |
|
17 |
Pores |
18 |
Delivery nozzle |
19 |
Second non-return valve housing |
20 |
First non-return valve housing |
21 |
Valve socket |
22 |
Channel end flange |
23 |
Turning device |
1. A device for a fuel delivery unit (1), said device comprising
a channel (9) for conducting a fuel flow;
a filter unit (6) arranged for filtering the fuel flow;
a first non-return valve (4) arranged downstream of the filter unit (6), said first
non-return valve (4) allowing the fuel to flow freely in a first direction (F) but
preventing the fuel from flowing in a second direction; and
a second non-return valve (7) arranged upstream of said filter unit (6), allowing
the fuel to flow freely at a first flow rate in the first direction (F) but substantially
preventing the fuel from flowing in the second direction;
characterized by
leakage means (13) for allowing the fuel to flow at a second flow rate in the second
direction, from a downstream side to an upstream side of the second non-return valve
(7).
2. A device as claimed in claim 1, wherein the channel (9) comprises an essentially tubular
structure.
3. A device as claimed in claim 1 or 2, further comprising coupling means (12), adapted
for detachably interconnecting any two of: an end (9a, 9b) of said channel (9), the
filter unit (6), the first non-return valve (4) and the second non-return valve (7).
4. A device as claimed in claim 3, wherein the coupling means (12) are integrated with
at least one of the channel (9), the first non-return valve (4), the filter unit (6)
and the second non-return valve (7).
5. A device as claimed in claim 3, wherein the coupling means (12) are adapted for detachably
coupling one of the first non-return valve (4) and the filter unit (6) to a downstream
element (5, 10) within the fuel delivery unit (1).
6. A device as claimed in any of claims 1-5, wherein the first non-return valve (4) is
arranged at a first end (9a) of the channel (9).
7. A device as claimed in any of claims 1-6, wherein the filter unit (6) is arranged
at a first end (9a) of the channel (9).
8. A device as claimed in any of the preceding claims, wherein the filter unit (6) is
detachably arranged in said channel (9).
9. A device as claimed in any of the preceding claims, wherein the first non-return valve
(4) is arranged adjacent the filter unit (6).
10. A device as claimed in any of claims 1-8, wherein the first non-return valve (4) is
integrated with the filter unit (6).
11. A device as claimed in claim 10, wherein the first non-return valve (4) is detachably
integrated with the filter unit (6).
12. A device as claimed in any of the preceding claims, wherein the second non-return
valve (7) is arranged at a second end (9b) of the channel (9).
13. A device as claimed in any of the preceding claims, wherein the second flow rate is
substantially lower than the first flow rate.
14. A device as claimed in any of the preceding claims, wherein the leakage means (13)
is adapted for allowing a predetermined amount of fuel to flow in the second direction
during a predetermined time period.
15. A device as claimed in any of the preceding claims, wherein the second non-return
valve (7) is at least partly permeable.
16. A device as claimed in any of the preceding claims, wherein said leakage means (13)
comprises a hole in the second non-return valve (7).
17. A device as claimed in any of the preceding claims, wherein said leakage means (13)
comprises a by-pass channel leading the fuel past the second non-return valve (7).
18. A device as claimed in any of the preceding claims, wherein the channel (9) comprises
a flexible section that is arranged between said first and second non-return valves
(4, 7).
19. A device as claimed in any of the preceding claims, wherein the first non-return valve
(4) is arranged at a vertically higher level than the second non-return valve (7).
20. A device as claimed in any of the preceding claims, further comprising means (23)
for regulating the first non-return valve (4) between an open and a closed state.
21. A device as claimed in any of the preceding claims, wherein the second direction is
essentially opposite to the first direction (F).
22. A fuel delivery unit (1) comprising a device according to any of the preceding claims.
23. A fuel delivery unit (1) as claimed in claim 22, further comprising a pump (5) for
providing the fuel flow.
24. A fuel delivery unit (1) as claimed in claim 22 or 23, further comprising a fuel source
(11) from which the fuel is drawn.
25. A fuel delivery unit (1) as claimed in any of claims 23-24, wherein the pump (5) is
arranged downstream of the first non-return valve (4).
26. A fuel delivery unit (1) as claimed in any of claims 24-25, wherein the fuel source
(11) is arranged upstream of the second non-return valve (7).
27. A kit of parts for providing a device for a fuel delivery unit, said kit of parts
comprising
a channel (9) adapted for conducting a fuel flow;
a filter unit (6) adapted to be arranged for filtering the fuel flow;
a first non-return valve (4) adapted to be arranged downstream of said filter unit
(6), so that the first non-return valve (4) will allow the fuel to flow freely in
a first direction (F) but prevent the fuel from flowing in a second direction;
a second non-return valve (7) adapted to be arranged upstream of said filter unit
(6), in order to allow the fuel to flow freely at a first flow rate in the first direction
(F) but to substantially prevent the fuel from flowing in the second direction; and
leakage means (13) adapted for allowing the fuel to flow at a second flow rate
in the second direction, from a downstream side to an upstream side of the second
non-return valve (7).
28. A method for providing a detachable filter unit in a fuel delivery unit (1), the method
comprising the steps of
connecting a second non-return valve (7) to a fuel source (11), in order to allow
fuel to flow freely at a first flow rate in a first direction (F), while the fuel
is substantially prevented from flowing in a second direction;
providing leakage means (13) for allowing the fuel to flow at a second flow rate
in the second direction, from a downstream side to an upstream side of the second
non-return valve (7);
connecting a channel (9) to the downstream side of said second non-return valve
(7), in order to conduct the fuel from the fuel source (11);
arranging a filter unit (6) in the channel (9) in order to filter the fuel conducted
in the channel (9);
connecting a first non-return valve on a downstream side of said filter (6), in
order to allow the fuel to flow freely in the first direction (F) but prevent the
fuel from flowing in the second direction; and
connecting a downstream side of said first non-return valve (4) to a fuel drain
(10).
29. A method for replacing a filter unit that is positioned to filter a fuel flow conducted
in a channel of a fuel delivery unit (1), the method comprising the steps of:
disconnecting a first end (9a) of a channel (9) from one of a fuel drain (10), a filter
unit (6) and a first non-return valve (4);
allowing fuel remaining in the channel (9) to flow through a leakage means (13), in
a second direction, from a downstream side to an upstream side of a second non-return
valve (7), while performing the steps of:
removing one of the filter unit (6) and the filter (8);
inserting a new or restored filter (8) or filter unit (6); and
connecting the first end (9a) of the channel (9) to said one of the fuel drain (10),
the filter unit (6) and the first non-return valve (4).
30. The method of claim 29, further comprising the step of opening the first non-return
valve (4) prior to disconnecting the first end (9a).
1. Vorrichtung für eine Kraftstoffabgabeeinheit (1), wobei die Vorrichtung umfasst:
einen Kanal (9) zum Leiten eines Kraftstoffflusses;
eine Filtereinheit (6), die zum Filtem des Kraftstoffflusses angeordnet ist;
ein erstes Rückschlagventil (4), das stromab von der Filtereinheit (6) angeordnet
ist, wobei das erste Rückschlagventil (4) den Kraftstoff frei in einer ersten Richtung
(F) fließen lässt, jedoch verhindert, dass der Kraftstoff in einer zweiten Richtung
fließt; und
ein zweites Rückschlagventil (7), das stromauf von der Filtereinheit (6) angeordnet
ist und den Kraftstoff mit einer ersten Durchflussrate frei in der ersten Richtung
(F) fließen lässt, jedoch im Wesentlichen verhindert, dass der Kraftstoff in der zweiten
Richtung fließt;
gekennzeichnet durch:
eine Ableiteinrichtung (13), die den Kraftstoff mit einer zweiten Durchflussrate in
der zweiten Richtung von einer stromab liegenden Seite zu einer stromauf liegenden
Seite des zweiten Rückschlagventils (7) fließen lässt.
2. Vorrichtung nach Anspruch 1, wobei der Kanal (9) eine im Wesentlichen röhrenförmige
Struktur umfasst.
3. Vorrichtung nach Anspruch 1 öder 2, der des Weiteren Kupplungseinrichtungen (12) umfasst,
die so eingerichtet sind, dass sie von einem Ende (9a, 9b) des Kanals (9), der Filtereinheit
(6), dem ersten Rückschlagventil (4) und dem zweiten Rückschlagventil (7) zwei beliebige
Elemente lösbar miteinander verbinden.
4. Vorrichtung nach Anspruch 3, wobei die Kupplungseinrichtungen (12) eine Einheit mit
wenigstens dem Kanal (9), dem ersten Rückschlagventil (4), der Filtereinheit (6) oder
dem zweiten Rückschlagventil (7) bilden.
5. Vorrichtung nach Anspruch 3, wobei die Kupplungseinrichtungen (12) so eingerichtet
sind, dass sie das erste Rückschlagventil (4) oder die Filtereinheit (6) lösbar mit
einem stromab gelegenen Element (5, 10) in der Kraftstoffabgabeeinheit (1) kuppeln.
6. Vorrichtung nach einem der Ansprüche 1-5, wobei das erste Rückschlagventil (4) an
einem ersten Ende (9a) des Kanals (9) angeordnet ist.
7. Vorrichtung nach einem der Ansprüche 1-6, wobei die Filtereinheit (6) an einem ersten
Ende (9a) des Kanals (9) angeordnet ist.
8. Vorrichtung nach einem der vorangehenden Ansprüche, wobei die Filtereinheit (6) lösbar
in dem Kanal (9) angeordnet ist.
9. Vorrichtung nach einem der vorangehenden Ansprüche, wobei das erste Rückschlagventil
(4) an die Filtereinheit (6) angrenzend angeordnet ist.
10. Vorrichtung nach einem der Ansprüche 1-8, wobei das erste Rückschlagventil (4) eine
Einheit mit der Filtereinheit (6) bildet.
11. Vorrichtung nach Anspruch 10, wobei das erste Rückschlagventil (4) lösbar eine Einheit
mit der Filtereinheit (6) bildet.
12. Vorrichtung nach einem der vorangehenden Ansprüche, wobei das zweite Rückschlagventil
(7) an einem zweiten Ende (9b) des Kanals (9) angeordnet ist.
13. Vorrichtung nach einem der vorangehenden Ansprüche, wobei die zweite Durchflussrate
erheblich niedriger ist als die erste Durchflussrate.
14. Vorrichtung nach einem der vorangehenden Ansprüche, wobei die Ableiteinrichtung (13)
so eingerichtet ist, dass sie eine vorgegebene Menge an Kraftstoff während eines vorgegebenen
Zeitraums in der zweiten Richtung fließen lässt.
15. Vorrichtung nach einem der vorangehenden Ansprüche, wobei das zweite Rückschlagventil
(7) wenigstens teilweise durchlässig ist.
16. Vorrichtung nach einem der vorangehenden Ansprüche, wobei die Ableiteinrichtung (13)
ein Loch in dem zweiten Rückschlagventil (7) umfasst.
17. Vorrichtung nach einem der vorangehenden Ansprüche, wobei die Ableiteinrichtung (13)
einen Umgehungskanal umfasst, der den Kraftstoff an dem zweiten Rückschlagventil (7)
vorbeileitet.
18. Vorrichtung nach einem der vorangehenden Ansprüche, wobei der Kanal (9) einen flexiblen
Abschnitt umfasst, der zwischen dem ersten und dem zweiten Rückschlagventil (4, 7)
angeordnet ist.
19. Vorrichtung nach einem der vorangehenden Ansprüche, wobei das erste Rückschlagventil
(4) Vertikal höher angeordnet ist als das zweite Rückschlagventil (7).
20. Vorrichtung nach einem der vorangehenden Ansprüche, die des Weiteren eine Einrichtung
(23) zum Regulieren des ersten Rückschlagventils (4) zwischen einem geöffneten und
einem geschlossenen Zustand umfasst.
21. Vorrichtung nach einem der vorangehenden Ansprüche, wobei die zweite Richtung im Wesentlichen
entgegengesetzt zu der ersten Richtung (F) ist.
22. Kraftstoffabgabeeinheit (1), die eine Vorrichtung nach einem der vorangehenden Ansprüche
umfasst.
23. Kraftstoffabgabeeinheit (1) nach Anspruch 22, die des Weiteren eine Pumpe (5) zum
Erzeugen des Kraftstoffflusses umfasst.
24. Kraftstoffabgabeeinheit (1) nach Anspruch 22 oder 23, die des Weiteren eine Kraftstoffquelle
(11) umfasst, aus der der Kraftstoff abgesaugt wird.
25. Kraftstoffabgabeeinheit (1) nach einem der Ansprüche 23-24, wobei die Pumpe (5) stromab
von dem ersten Rückschlagventil (4) angeordnet ist.
26. Kraftstoffabgabeeinheit (1) nach einem der Ansprüche 24-25, wobei die Kraftstoffquelle
(11) stromauf von dem zweiten Rückschlagventil (7) angeordnet ist.
27. Satz von Teilen zum Schaffen einer Vorrichtung für eine Kraftstoffabgabeeinheit, wobei
der Satz von Teilen umfasst:
einen Kanal (9), der zum Leiten eines Kraftstoffflusses eingerichtet ist;
eine Filtereinheit (6), die so eingerichtet ist, dass sie zum Filtem des Kraftstoffflusses
angeordnet wird;
ein erstes Rückschlagventil (4), das so eingerichtet ist, dass es stromab von der
Filtereinheit (6) angeordnet wird, so dass das erste Rückschlagventil (4) den Kraftstoff
frei in einer ersten Richtung (F) fließen lässt, jedoch verhindert, dass der Kraftstoff
in einer zweiten Richtung fließt;
ein zweites Rückschlagventil (7), das so eingerichtet ist, dass es stromauf von der
Filtereinheit (6) angeordnet wird, um den Kraftstoff mit einer ersten Durchflussrate
frei in der ersten Richtung (F) fließen zu lassen, jedoch im Wesentlichen zu verhindern,
dass der Kraftstoff in der zweiten Richtung fließt; und
eine Ableiteinrichtung (13), die so eingerichtet ist, dass sie den Kraftstoff mit
einer zweiten Durchflussrate in der zweiten Richtung von einer stromab liegenden Seite
zu einer stromauf liegenden Seite des zweiten Rückschlagventils (7) fließen lässt.
28. Verfahren zum Schaffen einer lösbaren Filtereinheit in einer Kraftstoffabgabeeinheit
(1), wobei das Verfahren die folgenden Schritte umfasst:
Verbinden eines zweiten Rückschlagventils (7) mit einer Kraftstoffquelle (11), um
Kraftstoff mit einer ersten Durchflussrate frei in einer ersten Richtung (F) fließen
zu lassen, während der Kraftstoff im Wesentlichen daran gehindert wird, in einer zweiten
Richtung zu fließen;
Bereitstellen einer Ableiteinrichtung (13), die den Kraftstoff mit einer zweiten Durchflussrate
in der zweiten Richtung von einer stromab liegenden Seite zu einer stromauf liegenden
Seite des zweiten Rückschlagventils (7) fließen lässt;
Verbinden eines Kanals (9) mit der stromab liegenden Seite des Rückschlagventils (7),
um den Kraftstoff von der Kraftstoffquelle (11) zu leiten;
Anordnen einer Filtereinheit (6) in dem Kanal (9), um den Kraftstoff zu filtern, der
in dem Kanal (9) geleitet wird;
Verbinden eines ersten Rückschlagventils an einer stromab liegenden Seite des Filters
(6), um den Kraftstoff frei in der ersten Richtung (F) fließen zu lassen, jedoch zu
verhindern, dass der Kraftstoff in der zweiten Richtung fließt; und
Verbinden einer stromab liegenden Seite des ersten Rückschlagventils (4) mit einem
Kraftstoffablass (10).
29. Verfahren zum Austauschen einer Filtereinheit, die so angeordnet ist, dass sie einen
Kraftstoffftuss filtert, der in einem Kanal einer Kraftstoffabgabeeinheit (1) geleitet
wird, wobei das Verfahren die folgenden Schritte umfasst:
Trennen eines ersten Endes (9a) eines Kanals (9) von einem Kraftstoffablass (10),
einer Filtereinheit (6) oder einem ersten Rückschlagventil (4);
Ermöglichen, dass Kraftstoff, der in dem Kanal (9) verbleit, durch eine Ableiteinrichtung
(13) in einer zweiten Richtung von einer stromab liegenden Seite zu einer stromauf
liegenden Seite eines zweiten Rückschlagventils (7) fließt, wobei gleichzeitig die
folgenden Schritte durchgeführt werden:
Entfernen der Filtereinheit, (6) oder des Filters (8);
Einsetzen eines neuen oder regenerierten Filters (8) bzw. einer Filtereinheit (6);
und
Verbinden des ersten Endes (9a) des Kanals (9) mit dem Kraftstoffablass (10), der
Filtereinheit (6) oder dem ersten Rückschlagventil (4).
30. Verfahren nach Anspruch 29, das des Weiteren den Schritt des Öffnens des ersten Rückschlagventils
(4) vor dem Trennen des ersten Endes (9a) umfasst.
1. Dispositif pour une unité de distribution de carburant (1), ledit dispositif comprenant
un canal (9) destiné à diriger un écoulement de carburant ;
une unité de filtre (6) agencée pour filtrer l'écoulement de carburant ;
un premier clapet de non-retour (4) agencé en aval de l'unité de filtre (6), ledit
premier clapet de non-retour (4) permettant au carburant de s'écouler librement dans
une première direction (F) mais empêchant le carburant de s'écouler dans une seconde
direction ; et
un second clapet de non-retour (7) agencé en amont de ladite unité de filtre (6),
permettant au carburant de s'écouler librement à une première vitesse d'écoulement
dans la première direction (F) mais empêchant sensiblement le carburant de s'écouler
dans la seconde direction ; et
caractérisé par
un moyen de fuite (13) destiné à permettre au carburant de s'écouler à une seconde
vitesse d'écoulement dans la seconde direction, d'un côté aval vers un côté amont
du second clapet de non-retour (7).
2. Dispositif selon la revendication 1, dans lequel le canal (9) comprend une structure
essentiellement tubulaire.
3. Dispositif selon la revendication 1 ou 2, comprenant en outre un moyen de couplage
(12), adapté pour interconnecter de manière détachable deux quelconques des éléments
suivants : une extrémité (9a, 9b) dudit canal (9), l'unité de filtre (6), le premier
clapet de non-retour (4) et le second clapet de non-retour (7).
4. Dispositif selon la revendication 3, dans lequel le moyen de couplage (12) est intégré
à au moins un élément parmi le canal (9), le premier clapet de non-retour (4), l'unité
de filtre (6) et le second clapet de non-retour (7).
5. Dispositif selon la revendication 3, dans lequel le moyen de couplage (12) est adapté
pour coupler de manière détachable un élément parmi le premier clapet de non-retour
(4) et l'unité de filtre (6) à un élément en aval (5, 10) dans l'unité de distribution
de carburant (1).
6. Dispositif selon l'une quelconque des revendications 1 à 5, dans lequel le premier
clapet de non-retour (4) est agencé à une première extrémité (9a) du canal (9).
7. Dispositif selon l'une quelconque des revendications 1 à 6, dans lequel l'unité de
filtre (6) est agencée à une première extrémité (9a) du canal (9).
8. Dispositif selon l'une quelconque des revendications précédentes, dans lequel l'unité
de filtre (6) est agencée de manière détachable dans ledit canal (9).
9. Dispositif selon l'une quelconque des revendications précédentes, dans lequel le premier
clapet de non-retour (4) est agencé de manière adjacente à l'unité de filtre (6).
10. Dispositif selon l'une quelconque des revendications 1 à 8, dans lequel le premier
clapet de non-retour (4) est intégré à l'unité de filtre (6).
11. Dispositif selon la revendication 10, dans lequel le premier clapet de non-retour
(4) est intégré de manière détachable à l'unité de filtre (6).
12. Dispositif selon l'une quelconque des revendications précédentes, dans lequel le second
clapet de non-retour (7) est agencé à une seconde extrémité (9b) du canal (9).
13. Dispositif selon l'une quelconque des revendications précédentes, dans lequel la seconde
vitesse d'écoulement est sensiblement inférieure à la première vitesse d'écoulement.
14. Dispositif selon l'une quelconque des revendications précédentes, dans lequel le moyen
de fuite (13) est adapté pour permettre à une quantité prédéterminée de carburant
de s'écouler dans la seconde direction pendant une période prédéterminée.
15. Dispositif selon l'une quelconque des revendications précédentes, dans lequel le second
clapet de non-retour (7) est au moins partiellement perméable.
16. Dispositif selon l'une quelconque des revendications précédentes, dans lequel ledit
moyen de fuite (13) comprend un trou dans le second clapet de non-retour (7).
17. Dispositif selon l'une quelconque des revendications précédentes, dans lequel ledit
moyen de fuite (13) comprend un canal de dérivation amenant le carburant après le
second clapet de non-retour (7).
18. Dispositif selon l'une quelconque des revendications précédentes, dans lequel le canal
(9) comprend une section flexible qui est agencée entre lesdits premier et second
clapets de non-retour (4, 7).
19. Dispositif selon l'une quelconque des revendications précédentes, dans lequel le premier
clapet de non-retour (4) est agencé à un niveau verticalement supérieur au second
clapet de non-retour (7).
20. Dispositif selon l'une quelconque des revendications précédentes, comprenant en outre
un moyen (23) destiné à réguler le premier clapet de non-retour (4) entre un état
ouvert et un état fermé.
21. Dispositif selon l'une quelconque des revendications précédentes, dans lequel la seconde
direction est essentiellement opposée à la première direction (F).
22. Unité de distribution de carburant (1) comprenant un dispositif selon l'une quelconque
des revendications précédentes.
23. Unité de distribution de carburant (1) selon la revendication 22, comprenant en outre
une pompe (5) destinée à fournir l'écoulement de carburant.
24. Unité de distribution de carburant (1) selon la revendication 22 ou 23, comprenant
en outre une source de carburant (11) de laquelle le carburant est aspiré.
25. Unité de distribution de carburant (1) selon l'une quelconque des revendications 23-24,
dans laquelle la pompe (5) est agencée en aval du premier clapet de non-retour (4).
26. Unité de distribution de carburant (1) selon l'une quelconque des revendications 24-25,
dans laquelle la source de carburant (11) est agencée en amont du second clapet de
non-retour (7).
27. Ensemble de pièces destinées à fournir un dispositif pour une unité de distribution
de carburant, ledit ensemble de pièces comprenant
un canal (9) adapté pour diriger un écoulement de carburant ;
une unité de filtre (6) adaptée pour être agencée pour filtrer l'écoulement de
carburant ;
un premier clapet de non-retour (4) adapté pour être agencé en aval de ladite unité
de filtre (6), de sorte que le premier clapet de non-retour (4) permette au carburant
de s'écouler librement dans une première direction (F) mais empêche le carburant de
s'écouler dans une seconde direction ;
un second clapet de non-retour (7) adapté pour être agencé en amont de ladite unité
de filtre (6), afin de permettre au carburant de s'écouler librement à une première
vitesse d'écoulement dans la première direction (F), mais d'empêcher sensiblement
le carburant de s'écouler dans la seconde direction ; et
un moyen de fuite (13) adapté pour permettre au carburant de s'écouler à une seconde
vitesse d'écoulement dans la seconde direction, d'un côté aval vers un côté amont
du second clapet de non-retour (7).
28. Procédé pour fournir une unité de filtre détachable dans une unité de distribution
de carburant (1), le procédé comprenant les étapes consistant à
raccorder un second clapet de non-retour (7) à une source de carburant (11), afin
de permettre au carburant de s'écouler librement à une première vitesse d'écoulement
dans une première direction (F), alors que le carburant ne peut sensiblement pas s'écouler
dans une seconde direction ;
fournir un moyen de fuite (13) pour permettre au carburant de s'écouler à une seconde
vitesse d'écoulement dans la seconde direction, d'un côté aval vers un côté amont
du second clapet de non-retour (7) ;
raccorder un canal (9) au côté aval dudit second clapet de non-retour (7), afin
de diriger le carburant depuis la source de carburant (11) ;
agencer une unité de filtre (6) dans le canal (9) afin de filtrer le carburant
dirigé dans le canal (9) ;
raccorder un premier clapet de non-retour sur un côté aval dudit filtre (6), afin
de permettre au carburant de s'écouler librement dans la première direction (F) mais
d'empêcher le carburant de s'écouler dans la seconde direction ; et
raccorder un côté aval dudit premier clapet de non-retour (4) à un canal d'évacuation
de carburant (10).
29. Procédé pour remplacer une unité de filtre qui est positionnée pour filtrer un écoulement
de carburant dirigé dans un canal d'une unité de distribution de carburant (1), le
procédé comprenant les étapes consistant à :
détacher une première extrémité (9a) d'un canal (9) d'un élément parmi un canal d'évacuation
de carburant (10), une unité de filtre (6) et un premier clapet de non-retour (4)
;
permettre au carburant restant dans le canal (9) de s'écouler à travers un moyen de
fuite (13), dans une seconde direction, d'un côté aval vers un côté amont d'un second
clapet de non-retour (7), tout en effectuant les étapes consistant à :
retirer un élément parmi l'unité de filtre (6) et le filtre (8) ;
insérer un filtre (8) ou une unité de filtre (6) neuf ou réparé ; et
raccorder la première extrémité (9a) du canal (9) à l'un desdits éléments parmi le
canal d'évacuation de carburant (10), l'unité de filtre (6) et le premier clapet de
non-retour (4).
30. Procédé selon la revendication 29, comprenant en outre l'étape consistant à ouvrir
le premier clapet de non-retour (4) avant de détacher la première extrémité (9a).