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1. * GB780129 (A)
Description: GB780129 (A) ? 1957-07-31
Improvements in or relating to liquid pipelines
Description of GB780129 (A)
COMPLETE SPECIFICATION.
Improvements in or elaig to x.u1.c Pixoe
We, SHELL RESEARCH LIMITED, a
British Company, of St. Helen's Court, Great
St. Helen's, London, E.C.3, do hereby declare the invention for which
we pray that a patent may be granted to us, and the method by which it
is to be performed, to be particularly described in and by the
following statement:
The present invention relates to liquid pipelines, and whilst it is
generally applicable to pipelines for the transfer of liquids which
are immiscible or substantially immiscible with water, it is
particularly applicable to the pipelines which are used for the
transfer of hydrocarbon fuels from one reservoir to another, for
example, for the transfer of aviation fuel from a refuelling tanker or
a hydrant refuelling system to the storage tanks of an aircraft.
References to liquids in this Specification are to be understood to be
confined to those liquids which are immiscible or substantially
immiscible with water.
Particularly in cases such as the example quoted in which oil is being
delivered to a reservoir from which it is drawn for use a fuel, it may
be important that the oil being delivered should not contain water.
However, contamination with water can occur at some stage before
delivery and whilst certain procedures may be laid down for detecting
the presence of water in the oil in the reservoir from which it is
transferred, and for preventing its transference, an automatic
mechanical safeguard to stop the flow of oil as soon as water has been
detected is preferred, and it is therefore an object of the present
invention to provide apparatus for this purpose.
According to the present invention a liquid pipeline is provided with
apparatus responsive to the presence of water in liquid in the

2. pipeline, said apparatus comprising a filter pack of the kind
specified (as defined below) located in the path of liquid flowing
through an auxiliary channel ir,terconnecting two points spaced along
the main liquid flow channel, and means responsive to expansion of the
filter pack for indicating the presence of water and/or automatically
stopping the flow of liquid through the pipeline.
Reference has been made above to "filter packs of the kind specified".
This kind of filter pack is to be understood to be one which consists
in a mass of filter material, for example, impregnated filter paper,
which mass will permit the passage of liquid other than water through
it, but absorbs water carried in the liquid stream, and is so arranged
that on so doing it expands sufficiently to produce a mechanical
movement sufficient to actuate a suitable form of valve or valve
operating mechanism, such as a servo mechanism, and/or the actuating
mechanism of an indicating device. The latter may be either
electrical, mechanical or hydraulic. One form of filter pack of the
kind specified consists of a pack of annular filter papers compressed
between end plates and mounted on a triangular section rod passing
through the centre channel of the pack. Liquid flows through the pack
from outside the external cylindrical surface to the centre channel
within.
According to another aspect of the present invention there is provided
a liquid pipeline section adapted to be joined at either end to other
sections of pipeline or allied equipment, said section including
apparatus responsive to the presence of water in liquid being passed
through the section in the normal direction of liquid flow, said
apparatus comprising a filter pack of the kind specified located in
the path of liquid flow
ing through an auxiliary channel intereon-.
necting two points spaced along the main
liquid flow channel through the section, and
means responsive to expansion of the filter pack for indicating the
presence of water
and/or automatically stopping the flow of
liquid through the pipeline.
Further according to the present invention
there may be provided a reservoir for holding a stock of liquid for
supply to other reservoirs, for example aircraft fuel tanks,
said one reservoir being flitted with a pipeline for delivering liquid
to said other reservoirs, which pipeline has joined in it
a section as set out in the previous paragraph.
The filter pack may be included in an
arrangement whereby, on expansion, of it, the auxiliary channel is
closed, and in such a case said responsive means may then include a

3. main valve located in the main channel between the said two points and
a valve actuating. mechanism responsive to the liquid flow conditions
in the auxiliary channel for closing. the main valve when flow of
liquid through the auxiliary channel ceases.
Some grades of filter packs of the kind specified are sufflciently
sensitive to the absorption of a small quantity of water to seal
themselves against further flow of liquid through them In.
consequence, when a filter pack of these grades is included in an
arrangement as set-out in the previous paragraph, the self-sealing of
the filter pack itself is used to close the. auxiliary channel. When
other - grades of filter - pack are - included in such an arrangement
the arrangement will include a. valve. for closing the auxiliary
channel on expansion of the. filter pack..
The valve actuating mechanism responsive to the liquid: flow
conditions in the auxiliary channel may comprise a Venturi neck
mounted in the auxiliary channel upstream of the filter pack, and a
valve actuating mechanism for the main valve including a spring
biasing means- operating to close the valve and means responsive to
the difference
between the liquid pressures in the main
channel on the inlet side of the valve and at
a point in the Venturi neck in the auxiliary channel for opposing the
action of the biasing means and opening the main valve when the
difference exceeds a predetermined
amount. Said pressure difference responsive
moans may comprise a flexible bellows or
diaphragm open on one side to the liquid in
the main channel at the inlet side of the valve a liquid conduit
interconnecting the space on the other side of the bellows or
diaphragm
with the liquid at a point along the Venturi
neck in the auxiliary channel, and a spring
for extendin, the bellows or -diaphragm and
closing the valve when the pressures on either
side are equal.
Alternatively the valve actuating mechanism may comprise means for
supplying liquid under pressure to the mechanism under the control of
a further valve or valves in the auxiliary channel operated by the
flow of liquid through the auxiliary channel and/or expansion of the
filter pack, for supplying liquid from the auxiliary channel under
pressure to close the main valve when the liquid flow in the auxiliary
channel ceases and/or the filter pack expands, and to maintain the
main valve open whilst the liquid flow in the auxiliary channel
continues. The liquid may be supplied from the auxiliary channel to

4. either side of a flexible bellows or diaphragm movement of which
causes operation of the main valve, the further valves controlling the
supply of liquid to the appropriate side of the bellows or diaphragm
to open and close the mai l valve under the appropriate conditions.
The main valve is preferably of a balanced type, in order that its
operation is not affected by the liquid pressures on either side of
it, For example, it may be a butterfly valve, which, where the
pipeline is of circular cross section, includes a valve member of
elliptical. cross section the length of the minor axis of which is
equal to the internal diameter of the pipeline. The valve member is
mounted for rotation about its minor axis. and about a diameter of the
cross section of the pipeline, so that when the plane of the valve
member is parallel to the longitudinal axis of the pipeline the valve
is open and on rotation through an angle, for example, 39"-40", the
valve is closed.
In another arrangement, the filter pack is included in an arrangement
whereby, on expansion of it the auxiliary channel is closed, and sad
responsive means includes a main valve located in the main channel,
and a valve actuating mechanism arranged to be actuated by a
mechanical movement caused by expansion of the filter pack. Here again
the filter pack itself will be used to seal the auxiliary channel if
it is of sufficiently high grade, or it may be associated with a valve
for closing the auxiliary channel on expansion of the filter pack. The
valve actuating mechanism may be of any suitable form and may include
a servo mechanism. In such an arrangement, some suitable means is
provided for causing liquid flow through the auxiliary channel despite
the greater resistance to flow through that channel. Thus, the outlet
from the auxiliary channel may open into a Venturi neck situated in
the main channel at the downstream one of said two points, the
depression at the throat of the
Venturi neck being utilised to effect the desired flow. Alternatively
the or a pump for effecting flow in the main channel may be connected
in the main channel between the said two points.. the auxiliary
channel then constituting a separate flow circuit in tercollnectine,
the outlet and intake sides oa the pump.
Whilst the section of the pipeline in which the apparatus is
incorporated will usually be of rigid construction, the remainder of
the pipeline into which it is joined may be wholly or in pare
flexible.
As will be apparent from the example described below the apparatus
will usually be designed to operate when the liquid flows in only one
of the two possible diictions i l the main channel and in the
auxiliary channel, and where this is so terms such as "the inlet side
of a valve", "upstream", are used with reference to the normal

5. direction of liquid flow in the said channels.
Three embodiments of an oil pipeline in accordance with the present
invention will now be described by way of example with reference to
the accompanying drawings, in which
Figure 1 - shows a cross -section of an oil pipeline section according
to the present ininvention;
Figure 2 shows a cross section of a further oil pipeline section
according to the present invention:
Figure 3 shows part of Figure 2 on an enlarged scale;
Figure 4-shows a schematic arrangement of a third section; and
Figure 5 shows a part of the arrangement of Figure 4 in greater
detail.
In the first example, shown. in Figure 1, a short section of pipeline
having a main channel 1 of circular cross section is pra- vided with
an auxiliary channel 2 interconnecting two -points spaced apart along
the main channel 1. The ends of the section are provided with flanges
to enable it to be coupled to other sections of pipeline or other
apparatus. Other forms of coupling means may also be provided. In the
following description it will be assumed that the oil flow through the
main channel .1 in normal operation- takes place only in the direction
indicated by the arrow 3. Between the two points in the main channel 1
interconnected by the auxiliary channel 2, there is mounted the valve
member 4 of a butterfly valve for controlling the oil flow in the main
channel 1, although other types of valve may be employed if required.
This valve member 4 consists of an elliptical plate, the length of the
minor axis of which is equal to the diameter of the cross-section of
the main channel 1, The member 4 is mounted in bearings mounted
diametrically opposite one another in the wall of the main channel 1
so that it can rotate about a spindle S lying along its minor axis.
When the member 4 lies in a plane parallel to the longitudinal axis of
the main channel 1, it presents negligible obstruction to the liquid
flow through the main channel 1, but, as the member is rotated through
approximately 30 to the- position shown in Figure 1, it increasingly
obstructs the main channel 1 until it finally stops the flow
altogether. The movement ofthe valve member 4 is controlled by a rigid
rod 6 pivotally connected at one end to a point spaced along the major
axis of the member 4 from its centre, and connected at the other end
to the moving end plate 6a of a flexible bellows 7. The bellows 7 is
secured to the end wall 8 of a cavity 9 in the wall of the main
channel 1 lying upstream of the valve member 4. The bellows 7 contains
a compressed spring 10 which keeps the bellows 7 extended when the
fluid pressures inside and outside are equal and consequently by means
of the rod S forces the valve member 4 into the position shown in
Figure 1 in which it closes the main channull.

6. The entrance to the auxiliary channel 2 at the upstream end diverges
at only a small angle from the main channel 1. A Venturi neck 15 is
mounted in the entrance to the auxiliary channel 2, and from the
outlet of the neck 15, oil then flows to a -filter - pack 16 which is
of the kind specified. The filter pack 16 consists in a large number
of annular sheets of specially impregnated filter-paper held between a
pair of end plates 17 and 18 which are supported by a central- fl--d
19 passing down the central channel within the pack. The external
diameter of the-filter papers is less than the internal diameter of
the part of the auxiliary -channel 2-in which it is mounted, so that
an annular channel 20 is left between the wall of the auxiliary
channel 2 and the external surface of the filter packs 16. The
auxiliary channel 2 - bends beyond the filter pack 1G at nearly a
right angle to rejoin the main channel 1, but a short sealed branch
arm 21 is provided which is in effect an extension of the part in
which the filter pack 16 is mounted. The closure 22 at the end of the
branch arm 21 which is held for example by nuts and bolts securing it
and a gasket 22a to the flange on the end of the branch arm 21,
incorporates a support 23 into which the nearer end plate
1L7 of the filter pack 16 is screwed. This end plate 17 together with
the flange on the inner end of the support 23 closes the auxiliary
channel 2 at the downstream end of the filter pack 16, apart from a
central channel 24 through it which forms a continuation of the
central channel through the filter pack 16 around the rod 19. The rod
19 passes through the channel 24 to the other side of the plate 17 and
a valve member 25 is formed there, integrally with the end of the rod
19. The member 25, by movement towards the plate 17, comes up against
a valve seat 26 around the mouth of the channel 24, closing that
channel 24 and with it the auxiliary channel 2. A compressed spring 27
is included which tends to hold the valve member 25 away from the seat
26 and also holds the papers of the filter pack 16 in compression. An
O-ring seal 28 is mounted in an annulus on the outer surface of the
support 23. A further valve member 29 formed on the rod 19 is provided
as a precaution so that if the plates 17 and 18 are inserted without a
pack 16 between them. the channel 24 is closed by the valve member 29
coming up against the seating 30 under the force exerted by the spring
27.
The other end plate 18 of the filter pack 16, is rigidly connected to
the end of the rod 19, and blocks the entrance to the central channel
through the pack. It is a slide fit within the auxiliary channel 2,
but is provided with holes 31 (two of which appear in Figure 1)
permitting flow of oil intci the annular space 20 between the eternal
surface of the pack 16 and the wall of the auxiliary channel 2.
Small bleeder channels 32 open into tile channel in the Venturi neck

7. 15 and supply oil from it through an annular chamber 33 and a pipe 34
to the interior of tile bellows 7.
In operation, as long as a filter pad 16 is dry and in position, the
spring 27 forces the valve member 25 away from m the seat 26, thus
keeping the central channel 24 and thus the auxiliary channel 2 open.
With no oil in the pipeline section, the valve member 4 will be closed
by the action of the bias spring 10 within the bellows 7, since the
air pressures inside and outside the bellows 7 will be equal. On
pumping dry oil into the pipeline section, it will therefore initially
flow only through the auxiliary channel 2, passing through the Venturi
neck 15, through the holes 31 in the end plate 13 of the filter pack
16 to the annular space 20 between the external surface of the pad- 16
and the wall of the auxiliary channel 2, through the pack 16 itself,
out through the channel 24 in the end plate 17, and back through the
remainder of the auxiliary channel 2 into the main channel 1
downstream of the valve member 4. The bellows 7 will now be subject
eternally to the pressure of the oil on the inlet side of the valve
member 3. The interior of the bellows 7 however is subject only to the
smaller pressure of the oil as it flows through the constriction of
the Venturi neck 15, and the compression of the bias spring 10 is
arranged so that this difference under normal operating pressures is
sufficient to overcome the spring 10, depress the bellows 7 and rotate
the valve member 4 anticlockwise as it is shown in Figure 1, thus
opening tile main channel 1.
These conditions are maintained unless the oil contains sufficient
water which when absorbed on the filter pack 16 causes it to expand.
Expansion of the pack 16 will the end plate 18 to move away from the
other which is fixed, and after the absorption of only a small
quantity of water, the movement is sufficient to overcome the spring
27 holding open the valve member 25 away from the seat 26 and thus to
close the auxiliary channel 2. As flow through the
Venturi neck 15 decreases, the oil pressure inside the bellows 7
increases, towards the same value as the pressure at the inlet side of
the valve member ', until the pressure difference exerted on the
bellows 7 is insufficient to overcome the bias spring 10, whereupon
the bellows 7 expands closing the valve member '. The whole action can
be made to be nearly instantaneous so that only a very small quantity
of water can flow past before the main channel 1 is closed.
The larger the percentage of water in the oil, the quicker the filter
pack 16 expands and consequently the valve member 4 is closed.
If the filter pack 16 6 s should become clogged with material other
than water, the apparatus again operates to close the valve member 4
so that oil cannot be passed through the main channel 1 while the pack
16 is inoperative due to clogging. @ As the filter pack 16 starts to

8. clog, the f o,- through the auxiliary channel 2 will decrease for a
given pressure.
This will cause Xil-e liquid pressure inside the bellows 7 to
increase. owing to the reduced rate of flow through the Venturi neck
15, and the valve member 4 will start to close, causing a partial
obstruction of the main channel 1. @ This will increase the pres- sure
at the upstream end of the auxiliary channel 2, which will tend to
restore the rate of flow through the filter pack 16. Further dogging,
however, will eventually cause the valve member 4 to close entirely,
when the condition of the pack is such that the full operating
pressure cannot restore flow through it. As flow cannot now take place
through either channel 1 or 2, the need to replace the filter pack 16
will be evident to the operators in charge of the apparatus.
The filter pack 16 can be replaced by removing the closure 22, after
shutting off the oil flow of course, and withdrawing the filter pack
16 on its support sul
The second embodiment is shown in
Figures 2 and 3 in which the same references are used as in F@ ure 1
for identical parts), Fi Figure 3 showing he encircled part of
Figure 2 on a larger scale. The Venturi neck of the previous
embodiment is omitted from the auxiliary channel 2. The valve member
of the main valve. which is again a butterfly valve, is operated by a
rod 35 and lever 36, the lever 36 being secured to one end to the
spindle 5 on which the valve member 4 rotates. At the e!lrt the
spindl-e 5 is carried by a bearing 37 mounted in the wall of the main
channel 1, whilst at the other end it passes out through a bearing 38
and a gland carrying an O-ring seal 39. The rod 35 is moved to open
and close the valve member 4 by expansion of bellotvs 40 mounted in a
liquid tight chamber 41. Oil conduits 42 and 43 leading from the
chamber 41 communicate with the spaces in the chamber 41 inside and
outside the bellows 40. The chamber may, as shown, conveniently be
mounted on the outside of the main channel l.
The filter pack 16 is of similar construction to that shown in Figure
1, but is arranged slightly differently. The support for the filter
pack 16 is again mounted on the closure 22 for the branch arm 21 of
the auxiliary channel 2 and consists in a sleeve 45 extending up
inside the auxiliary channel 2 to beyond the upstream end of the pack
16. The sleeve 45 is a slide fit in the auxiliary channel 2 and is
provided at its upstream end with Owing seals 46 (see
Figure 3) for preventing leakage between its outer surface and the
wall of the auxiliary channel 2. Openings 47 in the sleeve 45 are
provided to allow oil to pass out of the sleeve 45 back to the main
channel.
The end plates 17 and 18 of the filter pack 16 lie within the sleeve

9. 45, the former being fixed in position and the latter being a slide
fit. As before, passages 31 in the plate 18 are provided for the flow
of oil to the annular space 20 surrounding the pack 16. Similarly the
valve member 25 on the end of the rod 19 is held away from the seat 26
by a compressed spring 27.
At the upstream end, there is a pressure operated valve 48, the main
member 49 of which is held dosed, in the absence of ail under pressure
in the entrance to the main channel 1, by the spring 50 which is
compressed between it and the end plate .18 of the pack 16. Integral
with the member 49 is the valve member 51 of an associated slide valve
which member 51 slides in a somewhat narrower passage 45a at the end
of the sleeve 45. The upstream space on the side of the valve member
49 communicates directly with the entrance to the passage 45a, through
the channel 52 in the valve member 51 and the parts 53. Flanges on the
member 51, which are provided with sealing rings (not shown)
preventing the passage of fluid between them and the wall of the
channel 45a, co-operate with narrow passages 54 and 55 through the
sleeve 45, to place one or other of the annular compartments 56 or 57
in communication with the interior of the channel 45a. If the member
49 is home, the passages 54 are open, and if the member 49 is away
from its seat, the passages 55 are open. Conduits 58 and 59 lead from
the compartments 56 and 57 and are joined as indicated by the letters
A and B on
Figures 2 and 3 to the conduits 42 and 43 leading to the exterior and
the interior respactively of the bellows 40 (Figure 2)
In operation, when there is insufficient oil pressure in the auxiliary
channel 2 to force the valve member 49 away from its seat, the
passages 54 are open and oil flows through the compartment 56, conduit
58 and conduit 42 to the exterior of the bellows 40 thus causing the
main valve member 4 to close.
When sufficient oil pressure builds up to open the valve member 49,
the passages 55 are opened, and oil is supplied to the interior of the
bellows 40 through the chamber 57 and conduits 59 and 43, thus causing
the main valve member Lli to open. If at any time there is sufficient
water in the oil to cause the pack 16 to expand the valve mem bers 25
and 49 close the auxiliary channel 2 and the valve member 4 also
closes with the valve member 49, since oil is now sup plied to the
exterior of the bellows 40 again.
In order to prevent hydraulic lock within the bellows 40 or the
chamber 41, additional conduits 60 lead from the spaces inside and
outside the bellows 40 to the inlet of the pump supplying the oil.
These conduits (i0 are provided with throttle plates 61 so that when
liquid pressure is applied either to the inside or the outside of the
bellows 40 it will not leak away until the source of pressure is cut

10. off by movement of the pressure operated valve 48. The throttle plates
61 will also prevent undesired build-up of pressure On either side of
the bellows 40 due to leakage past the flanges on the valve member 51.
In both embodiments described it may be possible to dispense with the
valve member 25 and its associated seat 26 at the downstream end of
the filter pack 16, if the filter material is of a grade such that, on
absorption of a small quantity of water, the pressure in the pack is
sufficient to seal it against fur- ther oil flow. In such a case, it
will be evident that the valve is redundant and need not be included.
The third embodiment, shown diagrammatically in Figures 4 and 5, is in
some ways rather simpler in construction, and operates by a slightly
different method, in that the expansion of the filter pack on the
absorption of water, causes a mechanical movement which itself is
utilised to shut off the flow in the main channel 1 by means of the
valve member 4. The filter pack 16 is mounted vertically in a
cylindrical chamber 70 (which is indicated schematically only in
Figure 4) the upper end plate 17 of the pack being secured to the
walls of the chamber 70, dividing it into upper and lower compartments
71 and 72, the only communication between which is through a number of
holes 73 in tfle end plate 17 which provide communication between the
upper compartment 71 and the central channel inside the filter pack
16. The normal direction of flow through the auxiliary channel 2 is
such that oil flows into the lower compartment 72 outside the filter
pack 16, through the pack 16, out through the holes 73 in the upper
end plate 17 into the upper compartment 71 and then back to the main
channel 1.
The lower end plate 18 of the filter pack 16 is secured to the rod 19
which extends through the central channel of the filter pad and up
through the upper end plate 17 and out of the chamber 70 through a
fluid
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