Note: Descriptions are shown in the official language in which they were submitted.
61~1
HOSE-BREAK VALVE
This invention relates to a hose--break valve for
pressure hoses or conduits with a surrounding protective
hose or conduit and a pressure medium in a space between
the pressure and protective hoses or conduits, said valve
having a sliding gate which is movable along a valve
housing between an open position and a closed position
preventing throughflow through the valve and which is
adapted to be actuated by said pressure medium to be held
thereby in the open position against the action of a load-
ing device yieldably actuating the sliding gate towardsthe open position and adapted to close the valve when the
pressure of said pressure medium falls short of a lower
limit value, so that the valve will prevent backflow of
gas or liquid from an appliance located downstream of the
valve upon leakage or break upstream of said valve.
A known hose-break valve of this type is described
in the published Swedish patent application 7702588-0 and
comprises a movable or displaceable sliding gate which is
actuated not only by the pressure medium enclosed between
the pressure conduit and the protective sleeve thereof,
but also by a spring pressure opposed to the pressure of
the pressure medium, the said two pressures maintaining
the sliding gate in a position permitting liquid to pass
through the valve when the said pressures counterbalance
each other, i.e. when they are equal, but displacing the
sliding gate in one or the other direction to close the
liquid flow through the valve when one or the other
pressure exceeds the opposed pressure, for instance upon
break of the pressure conduit and/or its protective
sleeve. The function of these known hose-break valves is
satisfactory, except when pressure surges occur in the
pressure conduit or in the pressure medium within the
protective sleeve, and when a small leakage occurs in
the pressure conduit or in the sleeve, Thus, it was found
that such pressure surges upset the spring-balanced
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6~1
position of the sliding gate, and furthermore the effects
of the pressure surges are aggravated because the sliding
gate is moved out of the balanced open position and par-
tially closes the throughflow through the valve. A small
leakage in the pressure conduit or in the sleeve will
cause the balanced position of- the sliding gate to be
displaced in one or the other direction from the open
-position of the valve, resulting in a partial throttling
which may remain over a long period of time until so much
pressure medium has leaked out that the valve will be
fully closed. Such long-term throttling of the flow through
the valve may result in considerable loss of power.
The present invention therefore has for its object
to obviate these shortcomings of the prior art hose-break
valves operating with a pressure medium to actuate a
sliding gate included in the valve. To achieve this object,
the hose-break valve of the present invention is charac-
terized by the features stated in the appended claims.
The invention will be described in detail in the
following, reference being had to the accompanying
drawings in which:-
Fig. 1 is a longitudinal section of a ~ortion ofa first embodiment of the invention;
Fig. 2 is a side view of a sleeve forming a valve
housing in the first embodiment;
Fig. 3 is a side view of a sliding gate in the
first embodiment;
Fig. 4 illustrates a tool attached to the valve for
mounting the valve and for emergency release thereofi
Fig. 5 is an exploded view of the details of a
valve releasing or pressure relieving mechanism in the
first embodiment;
Fig. 6 illustrates a detail of the first embodiment
of the invention;
Figs. 7 and 8 illustrate alternative embodiments of
the connection of the valve sliding gate to a protective
sleeve surrounding the pressure conduit;
Fig. 9 illustrates a modified embodiment of the
valve according to the invention;
Fig 10 illustrates a longitudinal section of
another embodiment of the present valve in open position;
Fig. 11 illustrates a longitudinal section of a
part of the valve of Fig. 10 in a partially closed
position; and
Figs. 12 and 13 show a side view and an end view,
respectively, of a valve housing in the ~alve shown in
Fig. 10.
In the embodiment of the present invention shown in
Figs. 1-6, the valve comprises a slidin~ gate 1 which is
slidable on a sleeve 2 forming the valve body or housing
and provided at one end with an externally threaded
connection 3 for connecting the valve to e.g. a hydraulic
cylinder and provided at its other end with an internally
threaded connection 4 which, as will appear from the
drawings, is connected to a pressure hose 5 by means of a
conventional hose coupling 6. The sliding gate 1 which
surrounds the valve sleeve 2 with a sliding fit, is
sealed against the valve sleeve 2 by means of sealing
rings 7 and is provided on its inner side with a circum-
ferential groove 8 having a width at least equal to the
outer distance between two rows of holes 10 and 11,
respectively, provided in the sleeve 2 on either side of
a wall 9 within said sleeve, the holes ~f each such row
having a diameter which makes the total area of the holes
of one row larger than the internal cross-sectional area
of said sleeve 2.
In the position shown in Fig. 1, which is the one
end position of the sliding gate and the fully open
position of the valve and which is determined by an ad-
justable abutment 12 which is shown in Fig. 1 in the form
of a nut on the threaded connection 3, the groove 8 over-
lies the two rows of holes 10, 11, thereby enabling
pressure medium, such as hydraulic fluid or pressure gas,
to flow through the valve in one or the other direction~
In this open position of the valve, the sliding gate 1 is
held urged against the nut 12 by a pressurized pressure
medium, such as a hydraulic fluid, a suitable gas or air,
which i5 enclosed within the space 13 and which is under
such a predetermined pressure that the pressure acts on
the sliding gate 1 with a force at least equal to and
preferably somewhat greater than the force exerted in the
opposite direction by a pressure sprin~ 17 mounted between
the nut 12 and the sliding gate 1. In this manner, also
the sliding gate 1 is held in the end position shown in
Fig. 1 and is unahle to move to the right in the said
Figure upon an increase of the pressure within the space
13 which is formed between the pressure hose 5 and an
outer hose 14 surrounding said pressure hose 5 over the
entire length thereof, said outer hose 14 being dimen-
sionally stable against at least said predetermined
pressure and functioning also as a protection for said
pressure hose 5. In Figs. 1 and 6-8 the pressure hose 5
is shown to be vulcani~ed with its end 15 to an end
socket 16 of the sliding gate 1. The socket 16 preferably
is provided with circumferential ridges serrated in cross-
section in order to establish an entirely tight connection
- between the gate and the outer hose. Naturally, such a
tight connection between these members can be achieved
also in some other manner, for instance by connecting the
hose end 15 with the end socket 16 of the sliding gate by
means of hose clips 50, as is shown in Fig. 9.
The pressure medium enclosed in the space 13 may be
either a liquid or a gas, such as air.
The pressure medium enclosed within the space 13 also
acts upon a rubber diaphragm 18 in a release or pressure
relieving mechanism 19 disposed within the sliding gate 1.
A cover 20 screwed to said sliding gate clamps the rubber
diaphragm 18 against a steel washer 23 which is supported
by a shoulder 21 in the sliding gate and sealed there-
against by means of an annular rubber seal 22. The rubber
diaphragm 18 is so dimensioned that it withstands at least
the pressure required to maintain the valve in the pOSitiQn
shown in Fig~ 1 against the action of the spring 17, but
ruptures at a predetermined pressure increase within the
space 13, i.e. when a predetermined up2er limit value of
the pressure ln ~he space 13 is exceeded. The release
mechanism 19 com~rises, besides the said diaphragm, a
pressure sleeve or tubular punch 26 displaceably mounted
in the sliding gate underneath the diaphragm and provided
with an ex~ernal flange 25, said pressure sleeve or punch
26 having an external diameter not greater than the
diameter of holes 28 provided both in the steel washer
and in the cover and aligned with one another and with
said pressure sleeve (see Fig. 5). Furthermore, the
pressure sleeve or punch 26 is formed at its end facing
the diaphragm 18 with a knife-edge 24. By means of a
pressure spring 27 disposed between the steel washer 23
and the flange 25, the pressure sleeve is yieldingly
held against a cam surface 29 formed in the valve body
2 and having a crest 30 and an end stop 31 determining
the other end position of the sliding gate.
In view hereof, even an insignificant leakage in the
pressure hose 5 will cause hydraulic fluid to leak into
the space 13, provided that the pressure in the space 13
is lower than the hydraulic pre~sure in the hose 5,
whereby the pressure in said space and thus also on the
diaphragm 18 will be increased successively, and this
pressure increase will continue until the diaphragm 18
ruptures, the sliding gate 1 being unable to leave the
position shown in Fig. 1 during this pressure increase.
As a result, the pressure in the space 13 drops and the
sliding gate 1 is rapidly moved by the pressure spring 17
; into its other end position determined by the end stop 31
and the pressure sleeve 26. In this position, the sliding
gate portion 32 overlies the holes 11 with its seals 7
sealing against the valve body 2 on either side of said
holes which thus are closed, whereby return flow of
hydraulic fluid from e.g. a hydraulic cylinder (not shown)
in the direction of the arrow 33 is prevented. In this
manner, also the cylinder or, rather, its piston is
locked in position and unable to move.
If the pressure in the space 13 between the pressure
6~
hose 5 and the outer hose 14 should drop more or less
slowly, the gate 1 will be urged by the pressure spring
17 to the left with respect to Fig. 1. Regardless of
whether the sliding gate 1 moves slowly or rapidly from
the end position shown in Fig, 1 into the other end
position, the pressure sleeve 26 will be displaced radially
outwardly by the cam 29 of the valve housing or body so
that the knife-edge 24 of the pressure sleeve cuts or
punches a hole in the diaphragm 18, thereby causing the
pressure in the space 13 to drop more rapidly and thus
the valve to close instantaneously everytime this is
required. It will be realised that the cutting or punching
operation effected by the pressure sleeve should take
place as quickly as possible after the sliding gate 1 has
been set in motion by the pressure spring 17, during which
motion the pressure sleeve 26 thus is guided by the cam 29
which, when the pressure sleeve 26 has passed the crest 30,
permits the pressure spring 27 to displace the pressure
sleeve 26 radially inwardly so that said sleeve can abut
the end stop 31 and arrest the sliding gate in its other
end position, i.e. the closed position of the valve.
In this other end position, the outer hose 14 shown
in Fig. 1 exhibits the wavy shape which is shown in
Fig. 6 and which permits an extension of the hose corre-
sponding at least to the distance which the sliding gatehas travelled. The outer hose always strives to return to
this wavy shape when it has been deformed.
In view hereof, the hose 14 will contribute in moving
the sliding gate 1 from the open to the closed position.
Furthermore, it is possible, within the scope of the
invention, to replace the pressure spring 17 by a tension
spring built into the hose 14, or other tensioning member
providing for rapid movement of the sliding gate 1 from
open to closed position as soon as the pressure in the
space 13 drops.
The above described embodiment of the arrangement
causes a rapid pressure drop in the space 13, not only
when the diaphragm 18 ruptures~ but also as soon as a
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611
leaka~e or break occurs in the outer hose 14, and the
valve according to the invention will therefore function
also in such cases. ~he pressure drop in this
instance does not depend on a rupturing of the diaphragm
but on the cutting of a hole in the diaphragm 18 when the
pressure in the space 13 has fallen below a predetermined
lower limit value and the sliding gate 1 has been moved
a given distance towards the closed position. In the
event a predetermined, maximally permissible pressure
increase in the space 13 is exceeded, the diaphragm will
rupture. Such a pressure increase may occur upon leakage
or break in the inner hose 5, The hose-break valve
according to the present invention will thus function
satisfactorily regardless whether only the inner hose,
only the outer hose, or both the inner hose and the outer
hose should rupture, and also regardless of the sequence
of such ruptures.
Should it not be possible to tension the pressure
spring 17 and/or the hose 14 by hand when the valve is
mounted or after the valve has been released and a new
rubber diaphragm 18 has been mounted in the release
mechanism 19, the too] illustrated in Fig, 4 can be used.
This tool has a fork-shaped end 35, a body 37 having a
slot 36, and a portion 39 carrying a set screw 38. The
tool is hooked with its fork-shaped end over the valve
connection 3 and firmly pulled against the nut 12, where-
upon a stop screw 40 extending through the slot 36 is
screwed into a threaded hole 41 in the sliding gate 1
which can then be moved into its end position by means of
30 the set screw 38 opposite the stop screw 40, while ten-
sioning the pressure spring 17 and/or the hose, and/or
other tensioning member which may be built into the hose,
whereupon pressure medium is introduced into the space 13
until the pressure required for maintaining the sliding
gate in its position abutting the nut 12 has been reached.
The tool may be used also for emergency release of the
valve. To enable the tool to be mounted in different
positions on the valve, a number of holes should be
114bi6~
provided around the periphery of the sliding gate 1.
Fi~. 7 shows an alternative embodiment of the
connection of the outer hose to the end sleeve 16 of the
sliding gate, and this alternative embodiment comprises
S a sleeve 43 movable relative to said sliding gate 1 and
sealed thereagainst by means of a seal 42, said sleeve
43 serving to protect and support a jointing hose 46
which extends between the outer sleeve or hose 14 and
the end sleeve 16 of the sliding gate and which, because
the sleeve 43 is made for instance of steel, may be
essentially thinner and more elastic and flexible than
the outer sleeve or hose 14. The jointing hose 46 is
vulcanised to the outer sleeve or hose and to the end
sleeve 16 at 45, while the sleeve 43 is secured to the
jointing hose 46 by means of a clamp 44 or the like.
Also in the embodiment shown in Fig. 8, the jointing
hose 46 is vulcanised to the end sleeve 16 and to the
outer hose 14. The embodiment according to Fig. 8 distin-
guishes over the embodiment shown in Fig. 7 merely in that
the jointing hose 46 is vulcanised to an intermediate
sleeve 90 which in turn in vulcanised at 45 to the outer
hose or sleeve 46, and in that the sleeve 43 is fixedly
connected at its end facing the valve with the jointing
hose 46, but is movable relative to said jointing hose
at its other end which is sealed against the jointing
hose by means of seals 47. Fig. 8 shows the jointing hose
in the open position of the valve, while Fig. 7 shows
the jointing hose 46 in the closed position of the valve.
The embodiment shown in Fig~ 9 illustrates that it
is also possible to dispose the sliding gate 1 movable
within a steel casing comprising two portions 48, 49 of
which the portion 48 is screwed onto the portion 49~ In
this embodiment, the rubber diaphragm 18 of the axially
disposed release or pressure relieving mechanism 19 is
clamped against the shoulder 21 by means of a hollow nut
52 screwed into an opening 51 in the sliding,gate 1. The
pressure sleeve or punch 26 which in this instance is
provided with throughholes 53 for the pressure medium ('as
4~6~
is the case also in the embodiment shown in Fig, 5) is
here actuated directly by the sliding gate 1. A number of
pressure sprin~s 55 are disposed between the portion ~9
and the sliding gate 1. The space 13 is supplied with
pressure medium through a nipple 56.
The embodiment, illustrated in Figs. 10-13, of the
hose-break valve according to the present invention
possesses, like the embodiments previously described, a
sliding gate 1 movably mounted on a valve body or housing
2. The arran~ement of the circumferential groove 8 of the
sliding gate and the sealing rings 7, the rows of holes
10, 11 and the wall 9 of the valve housing is the same
as in the embodiments previously described, except that
the wall 9 also has a circumferential groove accommodating
a sealing ring 60. The sealing ring 60 seals against the
inner side of the sliding gate portion 32 when the valve
is in the closed position. The valve housing has a
narrower portion 62 with a bevelled face 63 at the end
adjacent the row of holes 11. The sliding gate 1 has at
its end a corresponding inwardly directed, bevelled
flange 64 which, when the sliding gate 1 is moved to the
left with respect to Fig, 10, will engage the bevelled
face 63 which serves as a stop when the valve is fully
closed.
Compared to the embodiments previously described,
the valve housing 2 has been extended to the left with
respect to Fig. ].0 and thus has a cylindrical portion 65,
a thicker portion 66 beyond said portion 65, and, beyond
said thicker portion 66~ a sealing portion 67 for the
30 outer holes 14. Extending through said portions 65, 66
and 67 are two longitudinal bores 68 connecting the space
13 between the hoses 5 and 14 with the inner cavity 69 of
the hose-break valve so that the pressure medium within
the space 13 can freely flow to the cavity 69 and act
directly on the sliding gate to move the latter towards
the right against the action of the pressure-spring 17
which is clamped between the sliding gate and the nut 12
screwed onto the threaded portion 3 of the valve housing~
.
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611
To sea] the cavity 69 against the surroundings, the portion
65 of the valve housing has two sealing rings 70 which are
placed in grooves and seal against the inner side of the
cylindrical bore provided in the sliding gate 1 and
defining the cavity 69.
In the embodiment illustrated, the sliding gate 1 has
an external thread 72 with a screwed-on union nut 73~ the
free end 74 of which is adapted to cooperate with the
shoulder 75 between the portions 65 and 66 of the valve
housing. In the fully closed position of the valve (deter-
mined by the engagement of the inwardly facing flange 64
of the sliding gate with the bevelled face 63 of the
valve housing~ the surface 74 of the nut 73 normally is
a short distance from the shoulder 75~ The nut 73 can be
utilized for wholly or partly opening the valve by hand,
if this should be necessary in the event of a hose-break.
By screwing the nut 73 outwards on the threads 72 of the
sliding gate 1, the latter can thus be moved to the right
with respect to Fig. 10 so that the spring 17 will ayain
be compressed and the inner groove 8 will enable the pres-
sure medium to pass between the rows of holes 10 and 11.
The valve housing 2 shown in Figs. 10-13 has a
filling nipple 56 which is screwed into a threaded hole
76 in the portion 66 and opens into one of the longitudinal
bores 68 to permit filling of pressure medium into the
space 13. On the opposite side, another bore 77 is pro-
vided which opens into the other bore 68 but is provided
at its inner end with a circumferential shoulder 78
against which a rupturable diaphragm 18 of elastomer or
other suitable material is clamped by means of a nut 52
having a through hole 79. The details 1~, 52, 78-79
constitute a first pressure re~ieving device 19 which is
adapted, when the pressure of the pressure medium within
the space 13 exceeds a predetermined upper limit value,
to relieve the pressure within said space by rupturing
the diaphragm 18. The pressure relieving device 19 may
also be a safety valve having an adjustable limit value
pressure. The essential thing is that, when the pressure
i
of the pressure medium exceeds an upper limit value, the
pressure within the space 13 will be relieved so that the
sprin~ 17 will move the sliding gate 1 into closed posi-
tion.
In order to release or close the valve also when-the
pressure of the pressure medium falls short of a pre-
determined lower limit value, the embodiment illustrated
in Figs. 10-13 comprises a second pressure relieving
device. In the embodiments previously described, this
second pressure relieving device is the punch 26 provided
with a knife-edge 24 for punching a hole in the diaphragm
18. In the embodiment illustrated in Figs. 10-13, this
second pressure relieving device is formed by a hole 80
which is bored into the sliding gate 1 and has an opening
81 which, when the sliding gate 1 is in the fully open
position shown in Fig. 10, lies between two sealing rings
82, 83 on the valve housing 2. The arrangement is such
that already a slight lowering of the pressure in the
communicating spaces 13, 68, 69 causes the spring 17 to
move the sliding gate 1 to the left so that, when the
pressure of the pressure medium falls short of the lower
limit value, the opening 81 in the sliding gate has moved
past the sealing ring 82 for instance into the position
- shown in Fig. 11. The play between the valve housing 2
and the sliding gate 1 will then cause the pressure medium
within the communicating spaces 13, 68, 69 to escape
through the opening 81 and the hole 82 so that the pressure
within these spaces will be lowered more quickly until the
valve is in fully open position. The speed at which the
pressure within the spaces 13, 68, 69 i~ relieved can be
determined by varying the relative diameters of the co-
operating portions of the housing and the sliding gate.
In the embodiment illustrated in Fig, 10, the con-
nection of the inner and outer hoses 5 and 17, respec-
tively, with the valve housing 2 is somewhat different.Thus, the inner hose 5 has been pushed over a clamping
portion 84 on the valve housing, and a slotted inter-
mediate sleeve 85 has been disposed around the hose end
12
so that said sleeve leaves a throughflow portion 86 to
esta~)lish communication between the spaces 13 a~d 69. The
outer hose 14 has been pushed over the intermediate sleeve
and the housing portion 68, whereupon two hose clamps 87
have been mounted for clamping the outer hose against the
portion 67 and the inner hose against the portion 84
through the intermediary of the outer hose 1~ and the
sleeve 85.
In the embodiment illustrated in Figs. 10-13, the
iO sliding gate 1 may well be made of steel and the valve
housing 2 of brass ox similar metal having a higher co-
efficient of linear expansion than the material of the
sliding gate 1. As a result of this arrangement, the
hose-break valve may be connected with this portion 3 to
a metal pipe in e.g. a gas supply system, in which case
a fire and the possible destruction of the hoses 13 and
14 will cause the valve to be released so that the
sliding gate 1 is moved to closed position, the rlange 64
of said sliding gate engaging the bevelled face 63 of the
valve housing. If the heat is so intense as to cause
destruction of all sealing rings, the higher coefficient
of linear expansion of the valve housing will cause the
latter to expand into firm and gas-tight engagement with
the inner side of the sliding gate 1 so that gas cannot
escape from the metal supply pipe connected with the
thread 3.
An important advantage of the hose-b~eak valve accord-
ing to the present invention, as compared with the prior
art hose-break valve disclosed by the above-mentioned
Swedish published patent application 7702~88-0, is that
the sliding gate 1 is held in a stable open position be-
cause it engages the nut 12 of the valve housing and the
end of the valve housing portion 49, respectively, when
the loading device or the spring 17 and 55, respectively,
are completely compressed. This rigid engagement between
the sliding gate and the valve housing in the fully open
position of the valve may be utilized for placing the
pressure medium within the space 13 under a pressure
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13
higher than is necessary for compressing the loaded
aevice 17, 55 so that a certain amount of pressuxe is
kept in reserve for a slow leakage of pressure medium
before release of the hose-break valve. q`hus, it is not
necessary exactly to adapt the pressure of the pressure
medium to an i~completely compressed loading device, as
is the case in the known hose-break valve disclosed by
the above-mentioned Swedish published application. Be-
sides, if such an exact adjustment had been necessary,
it would have required constan~ supervision and topping-
up of pressuxe medium via the nipple 56 to compensate
also for unavoidable leakage.
The hose-break valve according to the invention
should be mounted at either end of a pressure hose. By
connecting the spaces 13 of a group of valves in series
with one another, one attains the advantage that all of
the valves in the group are closed upon leakage or break
in a hose belonging to one valve.
