[001] The present disclosure generally relates to non-return valves. Particularly, but not
exclusively, the present disclosure relates to the non-return valves for ejecting exhaust
gases from combustion chamber. Further, embodiments of the present disclosure provide
a unidirectional flow of exhaust gases through the non-return valve and provide quick
return mechanism for the non-return valves.
BACKGROUND
[002] Non-return valves are common in industrial and domestic applications and are used
to allow flow of fluid in one direction. So as certain drawbacks associated with existing
non-return valves are such as higher weight resulting in back pressure, leakage, problem
of suction pressure created during closing of the valve, complex design, not suitable for
high temperature and low pressure applications. Moreover, the existing non-return valves
are manufactured by casting process resulting in manufacturing defects. The existing nonreturn valves do not facilitate quick return motion of the valve during closing of the valve.
[003] In view of above, there is an immense need in the art to provide an optimized
structure of non-return valve.
[004] The present disclosure is directed to overcome one or more limitations stated above
or any other limitations associated with the prior art.
SUMMARY OF THE DISCLOSURE
[005] One or more shortcomings of conventional systems have been overcome, and
additional advantages are provided through a non-return valve as claimed in the present
disclosure. Additional features and advantages are realized through the techniques of the
present disclosure. Other embodiments and aspects of the disclosure are described in detail
herein and are considered a part of the claimed disclosure.
3
[006] The limitations of the prior arts are addressed to a great extent by improving the
quick return mechanism for non-return valve in accordance with the present disclosure.
[007] The present disclosure relates to construction of non-return valve for allowing one
direction flow of gases coming out from Diesel Generator sets (hereinafter referred to as
DG sets). However, the non-return valve may be assembled in different applications or
systems in which one-direction flow of the gases takes place. The gases coming out from
DG sets are at high temperature and low pressure. Further, the non-return valve is also used
to restrict the flow of gases in other systems during the bypass situation.
[008] Additional features and advantages are realized through the techniques of the
present disclosure. Other embodiments and aspects of the disclosure are described in detail
herein and are considered as a part of the claimed disclosure.
[009] A non-return valve for low pressure and high temperature gases comprises a
housing defined with a first end opening and a second end opening. A seat extending from
the first end opening towards the second end opening. A flap pivotably connected to the
housing, such that the flap is adapted to rest on the seat in a closed position of the nonreturn valve. A quick return mechanism comprises a stiffener connected to the flap. The
stiffener is defined with an upper portion and a lower portion. The upper portion of the
stiffener is provided with one or more cutouts. The one or more cutouts are configured to
shift center of gravity of the flap towards the lower portion to facilitate quick return motion
of the flap during closing of the non-return valve.
[010] In an embodiment, the non-return valve is defined with a thickness ratio between
stiffener thickness and flap thickness which varies from 1:1.5 to 1:6.
[011] In an embodiment, the seat is defined with a wedge shaped structure to facilitate
proper seating of the flap during quick return motion of the flap.
4
[012] In an embodiment, the flap comprises a flange extending in a direction
perpendicular to a plane of the flap.
[013] In an embodiment, the non-return valve comprises a rod attached to the flange of
the flap by thermal joining process.
[014] In an embodiment, an at least two opposite co-axial slots are provided on an inner
surface of the first end opening of the housing.
[015] In an embodiment, the at least two co-axial slots are adapted to receive the rod to
facilitate pivotal movement of the flap.
[016] In another non-limiting embodiment, a quick return mechanism for a non-return
valve is described. The quick return mechanism comprises a stiffener connected to a flap
of the non-return valve. The stiffener is defined with an upper portion and a lower portion.
The upper portion of the stiffener is provided with one or more cutouts. The one or more
cutouts are configured to shift center of gravity of the flap towards the lower portion to
facilitate quick return motion of the flap during closing of the non-return valve.
[017] In an embodiment, the stiffener is defined with a profile dimension ratio varying
from 1.05:1 to 2:1.
[018] In an embodiment, the stiffener comprises a plurality of holes coinciding with a
plurality of circumferential holes of the flap. The plurality of holes and the plurality of
circumferential holes are adapted to receive a plurality of rivets for connecting the stiffener
with the flap.
[019] In an embodiment, the stiffener comprises a central aperture coinciding with a bleed
hole of the flap to facilitate ejection of exhaust gas during quick return motion of the flap.
5
[020] In another non-limiting embodiment, the one or more cutouts are formed on
opposite sides of a vertical axis Y-Y of the stiffener.
[021] It is to be understood that the aspects and embodiments of the disclosure described
above may be used in any combination with each other. Several of the aspects and
embodiments may be combined together to form a further embodiment of the disclosure.
[022] The foregoing summary is illustrative only and is not intended to be in any way
limiting. In addition to the illustrative aspects and features described above, further aspects
and features will become apparent by reference to the drawings and the following detailed
description
BRIEF DESCRIPTION OF ACCOMPANYING DRAWINGS
[023] Further aspects and advantages of the present invention will be readily understood
from the following detailed description with reference to the accompanying figure(s). The
figure(s) together with a detailed description below, are incorporated in and form part of
the specification, and serve to further illustrate the embodiments and explain various
principles and advantages, in accordance with the present invention wherein:
[024] FIG.1 illustrates an exploded view of a non-return valve, in accordance with the
embodiment of the present disclosure;
[025] FIG. 2 illustrates working positions of the non-return valve, in accordance with a
preferred embodiment of the present disclosure;
[026] FIG. 3 illustrates a top view of a stiffener, in accordance with a preferred
embodiment of the present disclosure;
[027] FIG. 4 illustrates an exploded view of flap and stiffener, according to an
embodiment of the present disclosure;
6
[028] FIG. 5 illustrates a top view of the stiffener attached with the flap, according to an
embodiment of the present disclosure;
[029] FIG. 6 illustrates a side view of the stiffener attached with the flap from FIG. 5,
according to an embodiment of the present disclosure;
[030] Skilled artisans will appreciate that elements in the drawings are illustrated for
simplicity and have not necessarily been drawn to scale. For example, the dimensions of
some of the elements in the drawings may be exaggerated relative to other elements to help
to improve understanding of embodiments of the present invention.
DETAILED DESCRIPTION
[031] While the invention is susceptible to various modifications and alternative forms,
specific embodiment thereof has been shown by way of example in the figures and will be
described in detail below. It should be understood, however that it is not intended to limit
the invention to the particular forms disclosed, but on the contrary, the invention is to cover
all modifications, equivalents, and alternative falling within the spirit and the scope of the
invention.
[032] It is to be noted that a person skilled in the art would be motivated from the present
disclosure and modify construction of a non-return valve. However, such modifications
should be construed within the scope of the disclosure. Accordingly, the drawings show
only those specific details that are pertinent to understand the embodiments of the present
disclosure, so as not to obscure the disclosure with details that will be readily apparent to
those of ordinary skill in the art having benefit of the description herein.
[033] The terms "comprises", "comprising", or any other variations thereof, are intended
to cover a non-exclusive inclusion, such that a system, device that comprises a list of
components does not include only those components but may include other components
not expressly listed or inherent to such setup or device. In other words, one or more
elements in a system or apparatus proceeded by "comprises... a" does not, without more
7
constraints, preclude the existence of other elements or additional elements in the system
or apparatus.
[034] Accordingly, the present disclosure provides a non-return valve to allow flow of
gases coming out from DG sets (not shown in figures) in one direction. DG sets are
provided to generate electricity for commercial building where high power transmission is
required. DG sets are the electric power generating units that uses diesel for its functioning.
The diesel is allowed to burn in combustion chambers in order to generate mechanical
energy and said mechanical energy is utilized to run mechanical components. The
mechanical energy is further converted into electrical energy during the combustion
process. The non-return valve is mounted on an exhaust manifold of the DG sets to
facilitate ejection or expelling of the exhaust gases from the combustion chamber into the
atmosphere in a one-directional manner. The non-return valve is also used to restrict the
flow of gases in other systems in which one direction flow of gases takes place. The nonreturn valve disclosed in the present disclosure is operable at high temperatures (i.e. up to
650° C) and low pressure.
[035] The non-return valve comprising a housing, a flap, a stiffener and a rod. The
housing is preferably having a cylindrical shaped structure which provides provisions for
mounting internal components and also protects the internal components from external
environment. The housing comprises a seat and a mounting portion for the rod. The seat
has a wedge shaped structure to provide proper seating for the flap to facilitate minimum
leakage of the exhaust gases. The mounting portion for the rod comprises two opposite coaxial slots. The slots adapted to receive the rod and allow its rotation therein with minimum
friction. The axial slots can be spaced in such a way to minimize the lateral movement of
the flap.
[036] In an embodiment of the present disclosure, the flap comprising at least one bleed
hole, plurality of circumferential holes and a flange. The flap is pivotably attached to the
housing by the rod received in the two co-axial slots. The bleed hole facilitates ejection of
exhaust gases during closing of the non-return valve. The said ejection of gases results in
lowering of suction pressure in order to prevent damage to the flap and to the seat of the
8
non-return valve. The plurality of circumferential holes are adapted to receive a plurality
of rivets passing through a plurality of holes on a stiffener. The stiffener is connected to
the flap as a counter-weight by means of the plurality of rivets. The stiffener is defined
with an upper portion and a lower portion, such that the upper portion is provided with one
or more cutouts. The cutouts provided in upper portion facilitates lowering of center of
gravity of the stiffener towards the lower portion. The stiffener being attached with the flap
by the plurality of rivets lowers the combined center of gravity to facilitate quick return
motion of the flap during closing of the non-return valve. The cutouts provided on the upper
portion of the stiffener may be of any shape or structure and may be one or more than one
in order to lower the center of gravity towards the lower portion of the stiffener. The
stiffener is also provided with a central aperture coinciding with the bleed hole provided
on the flap. The central aperture is configured to allow the flow of exhaust gases from the
combustion chamber or exhaust manifold into the atmosphere.
[037] The following paragraphs describe the present disclosure with reference to FIGs. 1
to 6. In the figures, the same element or elements which have similar functions are indicated
by the same reference signs.
[038] Referring to FIG. 1, an exploded view of a non-return valve in accordance with the
present disclosure is depicted. The non-return valve (100) for low pressure and high
temperature gases comprises a housing (1) defined with a first end opening (11) and a
second end opening (12). The non-return valve (100) comprises a seat (2), a flap (3) and a
stiffener (4) all enclosed in the housing (1). The housing (1) provides protection for internal
components like flap, seat, stiffener and likewise from external environment. The housing
(1) is preferably having a cylindrical shaped structure communicatively connected to an
exhaust manifold of the one-way device. The one-way device may be diesel generator sets
or other systems which require flow gases or fluids in one direction only. The first end
opening (11) of the housing (1) is defined as an input end that receives exhaust gases from
the combustion chamber or exhaust manifold of DG sets or other similar systems. The
second end opening (12) of the housing (1) is opened to atmosphere for expelling the low
pressure and high temperature exhaust gases into the atmosphere. The first end opening
9
(11) is defined with an inner surface (111) configured to attach the flap (3) with the housing
(1).
[039] Referring to FIG. 1 and FIG. 2, the seat (2) is integrally formed with the housing
(1), such that the seat (2) extends from the first end opening (11) towards the second end
opening (12) along a longitudinal axis X-X. The seat (2) may be removably attached to the
housing (1) by adapting different attachment means. The longitudinal axis X-X is defined
as an axis passing through the length of the non-return valve (100). The seat (2) extends
from the inner surface (111) of the first end opening (11) of the housing partially towards
the second end opening (12). The seat (2) is defined with a wedge shaped structure in
accordance with the present disclosure. The wedge shaped structure of the seat (2) has an
angle of inclination which may vary from 6 deg. to 14 deg but not limited to the same. The
seat (2) may be manufactured from a material which is having good damping property. The
damping property of the seat material prevents wearing off of the flap (3) by absorbing
impact forces during return motion of the flap (3). The wedge shaped structure of the seat
(2) provides proper seating of the flap (3) and utilization of damping material for
fabricating the seat (2) results in increase in life of the non-return valve (100) by reducing
the damage caused to the seat (2) during return motion of the flap (3).
[040] In an embodiment of the present disclosure, the flap (3) comprises a flange (31), a
bleed hole (32) and a plurality of circumferential holes (33). Referring to FIG. 1 and FIG.4,
the flange (31) extends in a direction perpendicular to plane of the flap (3) which provides
a mechanical advantage during opening and closing of the flap (3). The flange (31)
facilitates quick return motion of the flap (3). The flange (31) forms an L-shaped integral
structure with the flap (3) as shown in FIG. 6. The flange (31) is configured to attach a rod
(6) to provide pivotal motion to the flap (3) during operating conditions of the valve (100).
The rod (6) may be attached to the flange (31) by thermal joining process like welding etc.
The rod (6) is configured to receive in at least two co-axial slots (60, 61) formed on the
inner surface (111) of the first end opening (11) of the housing (1). The axial slots (60, 61)
can be spaced in such a way to minimize the lateral movement of the rod (6) and
10
simultaneously of the flap (3). The co-axial slots (60, 61) may be structured such that to
provide minimum friction to the rod (6) during pivotal movement of the flap (3).
[041] The bleed hole (32) provided at center of the flap (2) is adapted to expel excess
exhaust gases from the combustion chamber or the exhaust manifold during return motion
of the flap (3). When the gas flow source is closed a suction pressure is generated which
pulls the flap (3) towards the seat (2) and may damage the flap (2) or the seat (2). Thus, to
prevent the flap (3) from any kind of damage the bleed hole (32) is provided on the flap (3)
which allows the flow of exhaust gases through it during the closing of the flap (3). Thus,
it results in reduction of the suction pressure which get created during closing of the flap
(3).
[042] The plurality of circumferential holes (33) provide provision for connecting the
stiffener (4) with the flap (3) by using plurality of rivets (5) as shown in Fig. 1, FIG. 2 and
Fig. 6. The plurality of circumferential holes (33) are provided at equidistance from each
other around the circumferential region of the flap (3). The stiffener (4) may be connected
to the flap (3) by different attachment means to form an integral part with the flap (3). The
stiffener is defined with a plurality of holes (45) coinciding with the plurality of
circumferential holes (33) on the flap (3). The rivets (5) comprising a head portion and a
tail portion such that the tail portion is configured to initially pass through the plurality of
holes (45) on the stiffener (4) then through the plurality of circumferential holes (33) on
the flap (3) to rigidly connect the stiffener (4) with the flap (3). However, the connecting
method of the stiffener (4) to the flap (3) may be varied in accordance with the different
applications.
[043] In another embodiment of the present disclosure, the stiffener (4) provides a counter
weight for the flap (3) to increase the stiffness of the flap (3). Referring to FIG.s 3-5, the
stiffener (4) is defined with an upper portion (41) and a lower portion (42), such that the
upper portion (41) covers major area of the stiffener (4). Referring to FIG. 3, the stiffener
(4) is defined with a profile dimension ratio (a:b) which may vary from 1.05:1 to 2:1. The
upper portion (41) is provided with one or more cutouts (43) to reduce weight of the
11
stiffener (4) in upper portion (41) region. The cutouts (43) are configured to shift center of
gravity of the flap (3) towards the lower portion (42). The cutouts (43) in accordance with
the present disclosure are two in number and are symmetrical to each other. The cutouts
(43) are formed on opposite sides of a vertical axis Y-Y of the stiffener (4). The vertical
axis Y-Y is defined as an axis passing through a central hole (44) provided on the stiffener
(4) and perpendicular to the longitudinal axis X-X. Due to two symmetrical cutouts (43)
on the stiffener (4) , the weight of the stiffener (4) is reduced and since the cutouts (43) lie
in the upper portion (41), the center of gravity of the stiffener (4) is shifted downwards.
Thus, the downward shifting of center of gravity of the stiffener (4) results in quick return
motion of the flap (3) once there is no flow of the exhaust gases. The two symmetrical
cutouts (43) also result in reduction of weight of the flap (2) without limiting its stiffness.
The stiffener (3) is having a thickness indicated by (T) and the flap (2) is having thickness
indicated by (t), wherein the thickness ratio t:T varies from 1:1.5 to 1:6. The stiffener (4)
has a profile dimension ratio varies from 1.05:1 to 2:1. The term profile dimension ratio is
defined as (a:b) such that (a) is defined as a radial distance between outer periphery of the
symmetrical cutouts (43) & boundary of the stiffener (4) and (b) is defined as a distance
between two symmetrical cutouts (43) as shown in FIG. 3. The profile dimension ratio
(a:b) is defined in accordance with the minimum weight that can be given to the stiffener
(4). The central hole (44) provided at center of the stiffener (4) coincides with the bleed
hole (32) provided on the flap (2) to facilitate expelling of exhaust gases into the
atmosphere to reduce suction pressure. Each of the plurality of holes (45) provided on the
stiffener (4) coincides with the circumferential holes (33) on the flap (3) as shown in FIG.
4.
[044] In an embodiment of the present disclosure, working of the non-return valve (100)
is disclosed. When exhaust gases are allowed to pass through the housing (1) the gases
exert a force on the flap (3) resting on the seat (2). Since the flap (3) is pivotably mounted
on the housing (1), the force on the flap (3) results in pivotal movement of the flap from a
close position (A) to open position (B) as shown in FIG. 2 and allows flow of the exhaust
gases into the atmosphere. The close position (A) is defined as the position in which the
flap (3) rests on the wedge shaped seat (2) and the open position (B) is defined as the
12
position in which the flap (3) is not in contact with the wedge shaped seat (2). The flap (3)
is attached with the housing (1) and provides an opening angle of the flap (3) in the range
of 6 deg. to 90 deg but not limited to the same. Once the flow of exhaust gases is stopped
the flap (3) tends to move towards its close position (A) by the action of gravity. The center
of gravity of the stiffener (4) which is fixed with the flap (3) is located downward resulting
in a quick return motion of the flap (3). During the pivotal motion of the flap (3) from open
position (B) to close position (A), a suction pressure is generated which pulls the flap
towards the seat (2). The suction pressure generated during closing of the flap (3) may
damage the flap (3). The bleed hole (32) provided on the flap (3) facilitates reduction in
suction pressure by allowing flow of gases through the bleed hole (32) and the central hole
(44) on the stiffener (4) into the atmosphere during closing of the flap (3). Therefore, the
reduction in suction pressure prevents damaging of the flap (3) and increases the lifetime
of the non-return valve (100).
[045] The non-return valve disclosed in the present disclosure is used in application field
of ejecting exhaust gases from the diesel generator sets. However, the non-return valve can
also be used in different application fields. The non-return valve facilitates quick return
motion of the flap due to appropriate location of center of gravity of the flap. Further, the
suction pressure is reduced to negligible due to the presence of bleed hole on the flap,
wherein the size of bleed hole is determined using Choke-flow equation.
[046] Some of the advantages of the non-return valve disclosed in present disclosure are:
• Negligible suction pressure
• Negligible leakage of exhaust gases
• Quick return mechanism due to appropriate location of center of gravity
• Applicable for all sizes of hose
• Appropriate size of bleed hole, which is determined using Choke-flow equation
to prevent distortion of the flap due to suction pressure
• Flap is constructed such that it has less weight and high stiffness
• Design of flap and seat eases manufacturing tolerances
13
Equivalents:
[047] The embodiments herein and the various features and advantageous details thereof
are explained with reference to the non-limiting embodiments in the description.
Descriptions of well-known components and processing techniques are omitted so as to
not unnecessarily obscure the embodiments herein. The examples used herein are intended
merely to facilitate an understanding of ways in which the embodiments herein may be
practiced and to further enable those of skill in the art to practice the embodiments herein.
Accordingly, the examples should not be construed as limiting the scope of the
embodiments herein.
[048] The foregoing description of the specific embodiments will so fully reveal the
general nature of the embodiments herein that others can, by applying current knowledge,
readily modify and/or adapt for various applications such specific embodiments without
departing from the generic concept, and, therefore, such adaptations and modifications
should and are intended to be comprehended within the meaning and range of equivalents
of the disclosed embodiments. It is to be understood that the phraseology or terminology
employed herein is for the purpose of description and not of limitation. Therefore, while
the embodiments herein have been described in terms of preferred embodiments, those
skilled in the art will recognize that the embodiments herein can be practiced with
modification within the spirit and scope of the embodiments as described herein.
[049] Throughout this specification the word "comprise", or variations such as
"comprises" or "comprising", will be understood to imply the inclusion of a stated element,
integer or step, or group of elements, integers or steps, but not the exclusion of any other
element, integer or step, or group of elements, integers or steps.
[050] The use of the expression "at least" or "at least one" suggests the use of one or more
elements or ingredients or quantities, as the use may be in the embodiment of the disclosure
to achieve one or more of the desired objects or results.
[051] Any discussion of documents, acts, materials, devices, articles and the like that has
been included in this specification is solely for the purpose of providing a context for the
14
disclosure. It is not to be taken as an admission that any or all of these matters form a part
of the prior art base or were common general knowledge in the field relevant to the
disclosure as it existed anywhere before the priority date of this application.
[052] The numerical values mentioned for the various physical parameters, dimensions
or quantities are only approximations and it is envisaged that the values higher/lower than
the numerical values assigned to the parameters, dimensions or quantities fall within the
scope of the disclosure, unless there is a statement in the specification specific to the
contrary.
[053] While considerable emphasis has been placed herein on the particular features of
this disclosure, it will be appreciated that various modifications can be made, and that many
changes can be made in the preferred embodiments without departing from the principles
of the disclosure. These and other modifications in the nature of the disclosure or the
preferred embodiments will be apparent to those skilled in the art from the disclosure
herein, whereby it is to be distinctly understood that the foregoing descriptive matter is to
be interpreted merely as illustrative of the disclosure and not as a limitation.

We Claim:

1. A non-return valve (100) for low pressure and high temperature gases, comprising:
a housing (1) defined with a first end opening (11) and a second end opening (12);
a seat (2) extending from the first end opening (11) towards the second end opening (12);
a flap (3) pivotably connected to the housing (1), wherein the flap (3) is adapted to rest on
the seat (2) in a closed position of the non-return valve (100); and
a quick return mechanism comprising:
a stiffener (4) connected to the flap (3), wherein the stiffener (4) is defined with an upper
portion (41) and a lower portion (42);
the upper portion (41) of the stiffener (4) is provided with one or more cutouts(43), wherein
the one or more cutouts (43) are configured to shift center of gravity of the flap (3) towards
the lower portion (42) to facilitate quick return motion of the flap (3) during closing of the
non-return valve (100).
2. The non-return valve (100) as claimed in claim 1, wherein the non-return valve (100) is
defined with a thickness ratio between stiffener thickness (T) and flap thickness (t) which
varies from 1:1.5 to 1:6.
3. The non-return valve (100) as claimed in claim 1, wherein the seat (2) is defined with a
wedge shaped structure to facilitate proper seating of the flap (3) during quick return
motion of the flap (3).
4. The non-return valve (100) as claimed in claim 1, wherein the flap (3) comprises a flange
(31) extending in a direction perpendicular to a plane of the flap (3).
5. The non-return valve (100) as claimed in claim 1, wherein the non-return valve (100)
comprises a rod (6) attached to the flange (31) of the flap (3) by thermal joining process.
17
6. The non-return valve (100) as claimed in claim 1, wherein an at least two opposite coaxial slots (60, 61) are provided on an inner surface (111) of the first end opening (11) of
the housing (1).
7. The non-return valve (100) as claimed in claim 1, wherein the at least two co-axial slots
(60, 61) are adapted to receive the rod (6) to facilitate pivotal movement of the flap (3).
8. A quick return mechanism for a non-return valve (100), the mechanism comprising:
a stiffener (4) connected to a flap (3) of the non-return valve (100), wherein the stiffener
(4) is defined with an upper portion (41) and a lower portion (42);
the upper portion (41) of the stiffener (4) is provided with one or more cutouts (43), wherein
the one or more cutouts (43) are configured to shift center of gravity of the flap (3) towards
the lower portion to facilitate quick return motion of the flap (3) during closing of the nonreturn valve (100).
9. The quick return mechanism as claimed in claim 10, wherein the stiffener (4) is defined
with a profile dimension ratio (a:b) varying from 1.05:1 to 2:1.
10. The quick return mechanism as claimed in claim 10, wherein the stiffener (4) comprises
a plurality of holes (45) coinciding with a plurality of circumferential holes (33) of the flap
(3), and
the plurality of holes (45) and the plurality of circumferential holes (33) are adapted to
receive a plurality of rivets (5) for connecting the stiffener (4) with the flap (3).
11. The quick return mechanism as claimed in claim 10, wherein the stiffener (4) comprises
a central aperture (44) coinciding with a bleed hole (32) of the flap (3) to facilitate ejection
of exhaust gas during quick return motion of the flap (3).
12. The quick return mechanism as claimed in claim 10, wherein the one or more cutouts
(43) are formed on opposite sides of a vertical axis Y-Y of the stiffener (4)