Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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>?~sc.xiptiot
05 Safety sealing device for gas conduits
Te.c.hr~ic.~,~...~.x'.ea
The invention conce~.~ns a safety sealing device for gas conduits with a
valve body and a v<~.lve seat according to the introductory part of the first
patent claim.
These type of safety sealing devices serve, in cases of damage such as pipe
bursts or hose ruptures, to seal the gas conduit in order to prevent an
uncontrolled leakage of gas and thereby a dangerous situation.
State-of-the-art
Safety sealing devices have already been known, which are arranged
between the supply pipe and a user and which should ensure that, for
example with pipe bursts or hose ruptures, sealing of the supply pipe is
achieved.
Thus a safety sealing device known from by ~~rhich
is US-PS 4,830,06 a
2o spherical valve bod~r, withinhousing havinga connectingthread at
a both
ends, can be pressed against a valve seat,whereby valve body
the is
movable in the axial dit~ecaionof the valve seat againstthe force
of a
spring in the closure direction.Whilst, in the valve
the open body
position,
is supported on a circlip underthe action spring;
of a dmring
its closing
movement, it is controlled by this spring.
only
With this solution ii: is disadvantageous that both the screw-in component
serving as the cirrlip for the valve body in the open position and the
screw-in component forming the s~.ipport for the spring create restrictors
which prod~.ice an additional pressure loss. In order to guarantee the
desired flow volcime, a larger construction dimensions have to be put up
with. Thus there ar~~ further disadvantages in that due to the insertion of
the valve in a gas :supply line, two new external sealin5 points are created
and in that when
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combining the safety sealing device with another fitting, e.g. a hose cock,
its constructional len;~th is increased. When extending existing systems, it
is
05 necessary to correspondingly shorten the existing gas supply line.
Seen as a whole, this thereby results in a extensiva device due to the
connection threads and the components.
A further safety sealing device is described in WO 92/01184, which seals a
piping system should it be damaged without however effecting a premature
closure of the supply line should a mser need the amount of gas
corresponding to its output over a longer period of time. With this safety
sealing device, a valve is supported against the force of a spring such that
it can slide in the a~;ial direction of a tubular shaped housing of a slidable
plate valve. To achie~re this, discs with axial support positions for the
plate
valve are placed in the housing, the discs having penetrations for gas flow
around their ci.rcumf~~rences. The housing has threads at both facing ends
for connection to the piping or other fittings.
With this solution it is disadvantageous that the movement of the valve
head is conducted through supports. Because the available standing
pressure forces, which then in cases of damage act on the valve head for
the closure movement, is only a few millibars, the spring's force, which
determines the flow rate <xt which the safety sealing device should operate,
is extraordinary little. Each support friction substantially falsifies this
flow
rate ans is not reproducible.
This disadvantage is especially serious when it is considered that the valve
is not activated in normal operation and therefore no movement of the valve
shaft ensues within the bearing, which is exposed to contamination due to
the gas flow. The use of si.ich safety sealing devices is, amongst other
things, intended however with gas pipes that are laid underground which
means that they also have to retain their safety capabilities without
maintenance over a longer period of time e.g. several decades.
It is a further disadvantage that with the installation of the valve in a gas
pipe two new outward sealing points are made and that when combining the
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safety device with another fitting, e.g. a hose cock, its constructional
length is increased. 4~hen extending existing systems, it is necessary to
05 shorten the existing gas supply line correspondingly.
The penetrated discs which serve to bear the plate valve further create an
additional pressure loss.
Seen as a whole, also with this solution, this thereby results in a extensive
device due to the connection threads and the components.
De.scri.ption of...the, ir~~r,~n,ti.o.n
The invention 'takes as its basis the problem of creating a safety sealing
device for gas pipes by which the bearing of the valve body should be
frictionless, require no maintenance and which causes only minimal flow
resistance. Further i:he safety sealing device should not require outward
sealing connections. It should be easy to install and able to be fitted into
existing gas piping or fittings without having to change them.
According to the invention, the problem is solved in that the valve body is
on the spring of freely suspended plate, which rests in the open position
on a circlip elastically: deformable in the radial direction, «hich is itself
latched into a notch, which is preferably connected in one piece with the
valve seat. Due to the extremely log.- weight, this solution has the advantage
that the occurring mass reaction, depending on the installation location
which for example has influence on the deflection and balance of forces and
therefore also on the clos~.ire process, is kept very low.
Advantageous refinements of the invention are taken from the further
patent claims given later.
Thereby the circlip can be formed for example, by an expanding spring or
a slit annular ring which preferably has three inward flanges distributed
evenly around the circumference whereby the flow cross-section is reduced
only immaterially.
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That thereby to enable adjustment without changing the flow cross-section,
it is a proven advantage if the support shoulder of spring end facing the
05 valve body is adjustable in the axial direction in that it is connected,
for
example, to the valve seat by a thread. Due to this adjustable support
shoulder, a possibility for adjusting the safety sealing device has been
found which suffices without changing the flow cross-section.
Especially for use in connection with a commercial gas stopcock, it is an
advantage if the safety sealing device is inserted in the gas inlet of the
gas stopcock, whereby the plate of the safety sealing device has a lug-
shaped extension on its side facing the spring in the axial direction, which
protrudes from the s.~,me when the safety sealing device is closed whereas it
is within the same when the safety sealing device is open. It is of course
also possible that thEe valve seat made in one piece with the gas inlet of the
gas stopcock. Thereby the safety sealing device is located so far inside the
gas inlet that the lug-shaped extension protrudes into the swivel area of
the closure member of the gas stopcock. With this solution the safety-
sealing device can close completely sealed. A leakage flow bore for automatic
re-opening of the gas stopcock is not necessary. With the closing of the
gas stopcock, which is normally the case in damage repair, e.g replacing a
hose, the lug-shaped extension is pushed in the axial direction ~,~hereby the
safety sealing device is re-opened so that the gas can flozr again after
damage repair and on opening the gas stopcock.
In another advantageous refinement, because the outer diameter of the
valve body without elastic sealing element is smaller than inner diameter of
the valve seat associated to it, whilst. the outer diameter of the valve body
with the sealing element is larger than this inner diameter, and by this
means, that a circmlar shoulder is connected to the inner diameter of the
valve seat and itself' to a tubular end-piece in the flow direction, whose
length is so dimensioned that a blocking element, with withdrawn sealing
element, does not leave this tubiMar shaped end-piece in the closure
direction of the safety sealing device, whereas with a missing sealing
element, the valve body can be pressed so far into the valve seat that the
blocking element protrudes out of the end-piece, the installation can be
carried out very easily, in which the valve body together with the locking
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spring, the sealing element not being fitted, is placed so far into the valve
seat, that the blocking element can readily be connected to a lug belonging
05 to the valve boy in the flow direction. In conclusion, the installation of
the
sealing element is carried out.
It is an advantage that the lug is provided with a thread on which that for
example, a wire clip .as blocking element is easily attached and is adjustable
in the axial direction. of the lug for adjustment purposes.
Of course it also possible that the valve body is screwed on to the lug
thread in the flow direction whilst the blocking element, resting on the
shoulder of the valve seat, is rigidly attached to the lug thread.
Form. of., c.onstryctio.r~
25
35
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Fo.~m.....o~...GP...n.S.G.xt-~Ct~On.
05 The invention is described in detail in the following form of construction.
There is:
Fig. 1 A safety sealing device for gas pipes (accordingthe invention)
to in
the open position, sectional view.
Fig. A safety sealing device for gas pipes {accordingthe invention)
2 to in
the closed position, sectional view.
Fig. 3 A safety sealing device for gas pipes (accordingto the invention)
before installation of the elastic sealing
element
Fig. 4 .a safety sealing devic,e for gas pipes (accordingthe invention)
to in
another verson, in the open position, sectional
Vlew.
Fig. 5 A plan view A of s;~fety sealing device (accordingto the invention)
from Fig. 4.
Fig. 6 A safety sealing device for gas pipes (accordingth.e invention)
to in
a further version, in the open position,
sectional viem.
Fig. ~ safety sealing device for gas pipes (.accordingthe invention)
i to in
-3. fnrtr;er version c.~ith a freely suspendedbody- (6),
valve in the
ope:~ I~ositic~n, sectional vie~~-.
r i,. A plan view B of safety sealing device (accordingto the invention)
8
from Fig. 7.
Fig. A plan view B of safety sealing device {accordingto the invention)
9
from Fi j. 7 vrith a changed circlip for
the spring.
Fig. 10 An adjr.rstable safety sealing de-ice for (according
gas pipes to the
invention) in a further version, in the open
position, sectional vies.-.
Fig. 11 A safety sealing devi~~e for gas pipes (accordingthe invention)
to in
the gas inlet of a gas stopcock, iri the on.
closed positi
Fig. 12 A safety sealing device for gas pipes (accordingthe invention)
to in
the gas inlet of a gas stopcock, in the forcedposition.
open
Fig. 13 A safet;y sealing device for gas pipes (accordingto the invention)
used in an electrc>-welded sleeve, in the on.
open positi
Fig. A safety sealing device for gas pipes (accordingto the invention)
14
integrated with an electro-welded sleeve,
in the closed position.
Fig. 15 A circlip for application in an electro-welded.
sleeve
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The safety sealing device fox' gas pipes, according to the invention, shown
in Fig. 1 consists of a tu>r~ular shaped valve seat (1), which has at its
outer
05 diameter, which is otherwise smaller than the inner diameter gas pipe (26)
(not shown in different figures), a ring flange (2) whose diameter is on the
other hand larger than the inner diameter of gas pipe (26). In order to
guarantee an easy insertion of the safety sealing device, according to the
invention, the ring flange (2) is advantageously provided with an insertion
bevel {3). Further it is a proven advantage if the wing flange (2) is
provided with a circular groove (4) on both sides in order to achieve a
better elasticity by means of the enlarged height of the ring flange (2).
At its rear face, against the flow direction shown by an arrow, a sealing
surface (5) is located in the form of a concave ball. A valve body (6),
movable in the axial direction, is arranged within the valve seat ( 1 ) and
has
a ring shaped notch for the accommodation o.f a circular ring (7) serving as
a sealing element. Thereby the valve body (6) and circular ring {7)
dimensions are determined such that the outer diameter of valve body (6)
without circular ring (7) is smaller than the inner diameter of its associated
va.lwe seat (1) whilst the oi.zter diameter of the valve body (6) with mounted
circc.zlar ring ( r ) is hr.rger i;h.~,n this inner diameter.
On the flow direction side of valve body (6), one of the valve bodies (6) is
held supported in the open position by spring (8) preferably formed as a
compression spring, which is supported at its other end by circular
shoulder (9) v.~hich connector to valve body (6) with its associated inner
circumference of valve seat ( 1 ).
For guiding spring (8), the valve body (6) has a circular collar (10) on
which a lug (11) is connecaed in the flow direction. Lug (I1) has a throu.gh-
hole (12) at its end which serves to accommodate a blocking element (13), in
this case a rod (Fig. 1). There is the relationship between the length of lug
(11) and the length of they tubular shaped end-piece (14) connected on
shoulder (9), that tr..e blocking element (13) with mounted circular ring (7)
does not leave this i,,ubular shaped end-piece (14) in the closed position of
safety sealing device (Fig. 2) whereas without circular ring (7), the valve
body (6) can be pressed so far into the valve seat (1) that the blocking
element (13) protrudes out of the end piece (14) (Fig. 3).
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A somewhat different version is shown in Fig. 4. Hereby lug (11) is
provided with a thread and a wire clip (15), which is formed such that it
05 can be screwed on i:o lug (11) (Fig. 5) and serves as blocking element
(13).
In Fig. 6 a further version is shown. This solution differs from the
previous version in that the valve body (6) and the lug (11) consist of two
separate components whereby the val~~e body (6) has an a~ia.l threaded born
(16) with which it is screwed on to the threaded lug (11) located in the
flow direction upon which the supported blocking element (13) is rigidly
attached to shoulder {9) of valve seat (1). In order to guarantee the
necessary sealing and prevent twisting, an appropriate material, e.g. in this
case a commercial P'CFE (polytetraflorethylene} tape (17) is located between
lug (11) and the bore (16). In this version, an elastic sealing element is
dispensed with. To achieve the desired sealing efficiency, valve body (6) is
spherically shaped ~,vhilst the sealing surface (5) is executed as a bevel. To
accommodate spring (8) a.nd at the same time to reduce mass, valve body (6)
has additionally a recess (2'7).
In a further safety sealing dei-ice, according to the in~-ention shown in Fig.
7, the ring fl<~nge (2} found at. the end of val~-e seat (1) is made
significantly stronger than form of construction described above, tvhereby it
also has an insertion bevel (3). This type of valve seat (1) is especially
suitable for the installation in gas pipes consisting of polyethylene as they
are shown allusively under (26) in F'ig. 7. The safety sealing device is
hereby installed i.n which the gas pipe (26), e. g. consisting of polyethylene
pipe, is heated. The yielding component is in this case not the ring flange
(2) but the gas pipe (26}.
The valve body consists of a freely suspended plate (18) on spring (8)
which in the open position rests against an elastic radially deforrnable
circlip. In this form of construction, the circlip consists of, as can easily
be
recognized in Fig. 8, an expanding spring (20) which is latched into a
circular inner notch ( 19} of the valve seat ( 1 ).
It is obvious that instead of the expanding spring (20), other shaped
circlips can also be used. For example in Fig. 9, the circlip is formed by a
slit circular ring (24) which has preferably three inward flanges (25)
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arranged regularly a:round the circumference. Thereby it is to be observed
that the circlet surf~;ce area reducing the flow cross-section is to be kept
05 as low as possible.
A circular ring ('7) located on plate (18) serves to achieve the desired
sealing efficiency, w'~ilst the sealing surface (5) of valve seat (1) is on
the
other hand constructed in the form of a concave ball.
Because gas piping of polyethylene tubing is generally underground and
that the safety sealing device can only be reached with difficulty, the plate
(18) has a leakage pore (23), which leads to a definitive and self-evident
permissible leakage flow, whereby after repair of damage which caused the
safety sealing device to close, the device re-opens itself. .
In Fig. 10, the safety sealing device already described in Fig. 7 is changed
to the effect that the cir°clip shoulder (21), constructed as a
separate
component, is connected to valve seat (1) via a thread (22) and is thereby
adjustable in the axial direction. Thus an adjustment is made possible which
dispenses ~~-ith a change of the flow cross-section.
The use of the safety sealing device, according to the invention, in
connection with a commercial gas stopcock (29) is shown in Figures 11 and
12. Whilst in Fig. 11, the safety sealing device is inserted in the gas inlet
of the gas stop cocl.c, in Fig. 12 the valve seat ( 1 ) is constructed in one-
piece with the gas inlet of the gas stopcock (29). In both constrr.rctions,
plate (8) of the safei;y se;iling device has a lug-shaped extension (28) on
its
side facing spring (~c) in the axial direction, which protrudes from the
safety sealing device when it is closed (Fig. 11), whereas in the open
position of the safety sealing device the lug (28) is within it. Thereby
the safety sealing device is arranged so far in the gas inlet that the lug-
formed extension (28) protrudes into swivel range of the closure member
(32) of the gas stopcock (29) when the safety sealing device is closed. With
the closing of the gas stopcock (29), which usually takes place when
damage occurs, the lug-shaped extension (28), whose end is correspondingly
shaped, is pushed in the axial direction (Fig. 12), whereby the safety
sealing device completely re-opens again due to the effects of spring (8), so
that after darn<~ge repair gas flow can take place again when the gas
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stopcock (29) is opened.
05 With gas pipes (26) ~~onsisting of polyethylene tubing, connections are
made
in many cases by means of so-called electro-welded sleeves (30}. A safety
sealing device advantageous for this case is shown in Figures 13 and 14.
Whilst in Fig. 13, the safety sealing device is inserted in the electro-welded
sleeve (30}, in Fig. 14 the valve seat (1) is constructed in one-piece with
the same. In order to realize the circlip (33) simply for the plate (8), the
circular ring (24) which series as a circlip shown in Fig. 9 has teeth (34),
which press into the elec;tro-welded sleeve, in addition to the flanges (25)
distributed around the outer circumference.
As can be seen from both figures, the inner diameter of the safety sealing
device can be enlarged, as they are located outside the gas pipe (26),
whereby pressure reduction due to the safety sealing device can be
minimized.
In order to keep the constructional increase in length, which is necessary
in order to gi.ia.rantee the welding length used for connection with the gas
pipe (26), small, it is an advantage if the safety sealing dei-ice has a
detached collar (31 ) a.t i.ts o~.rtflow end, whose flow cross-section is
otherwise larger than the flow cross-section in the plate area, whereby the
outer diameter of the collar (3l.) is smaller than the inner diameter of the
oas pipe (26).
It is obvious that the individual constri.ictions described in this paragraph
lay no claim on completeness. For example it is possible that the individual
components given in the above construction can be interchanged withomt
leaving the claimed area of protection.
