U.S. patent application number 13/931447 was filed with the patent office on 2013-10-31 for water heaters with sealed door assembly.
The applicant listed for this patent is AMERICAN WATER HEATER COMPANY. Invention is credited to Marcus E. McAnally, Mark A. Murphy, Rodney R. Syler, Emadeddin Y. Tanbour.
Application Number | 20130284118 13/931447 |
Document ID | / |
Family ID | 42116266 |
Filed Date | 2013-10-31 |
United States Patent
Application |
20130284118 |
Kind Code |
A1 |
Tanbour; Emadeddin Y. ; et
al. |
October 31, 2013 |
WATER HEATERS WITH SEALED DOOR ASSEMBLY
Abstract
A water heater door assembly includes a base plate sized and
shaped to substantially sealingly cover an access opening in a
water heater combustion chamber and has at least one opening
through which a fuel supply line extends at least partly between a
burner in the combustion chamber and a gas control valve, and a
flexible seal positioned at least partly within the opening
including an engaging portion substantially sealed to an edge
portion of the opening, and a through hole that is shaped to
receive the fuel supply and has a size slightly smaller than the
size of an outer dimension of the fuel supply line such that the
flexible seal and the fuel supply line are friction fit together to
form a seal.
Inventors: |
Tanbour; Emadeddin Y.;
(Johnson City, TN) ; Syler; Rodney R.; (Franklin,
TN) ; Murphy; Mark A.; (Nashville, TN) ;
McAnally; Marcus E.; (Nashville, TN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
AMERICAN WATER HEATER COMPANY |
JOHNSON CITY |
TN |
US |
|
|
Family ID: |
42116266 |
Appl. No.: |
13/931447 |
Filed: |
June 28, 2013 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
12260259 |
Oct 29, 2008 |
8490580 |
|
|
13931447 |
|
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Current U.S.
Class: |
122/19.2 |
Current CPC
Class: |
F16J 3/041 20130101;
F23M 11/02 20130101; F24H 9/0026 20130101; F24H 1/186 20130101;
F16L 5/14 20130101; F23M 7/00 20130101; F24H 9/02 20130101 |
Class at
Publication: |
122/19.2 |
International
Class: |
F24H 9/02 20060101
F24H009/02 |
Claims
1. A water heater door assembly comprising: a door sized and shaped
to substantially sealingly cover an access opening in a water
heater combustion chamber, the door having a door opening through
which a burner fuel supply line extends at least partly between a
burner in the combustion chamber and a gas control valve; and a
unitary flexible seal positioned at least partly within the door
opening and comprising an engaging portion substantially sealed to
an edge portion of the door opening and having a through hole that
is shaped to receive the burner fuel supply line and having a size
slightly smaller than the size of an outer dimension of the burner
fuel supply line such that the flexible seal and the burner fuel
supply line are friction fit together to form a seal, the flexible
seal further comprising a first auxiliary opening sized and shaped
to sealingly receive one of a pilot fuel supply line and at least
one electrical wire extending through the door opening.
2. The water heater door assembly of claim 1, the flexible seal
further comprising a second auxiliary opening sized and shaped to
sealingly receive the other of the pilot fuel supply line and the
at least one electrical wire extending through the door
opening.
3. The door assembly of claim 1, wherein the engaging portion
includes a channel formed in a distal portion of the flexible seal,
the channel sized and shaped to sealingly engage the edge
portion.
4. The door assembly of claim 3, wherein the channel is
substantially U-shaped.
5. The door assembly of claim 1, wherein the flexible seal further
comprises: a flattened, O-ring shaped base portion having a
diameter larger than the burner fuel supply line and from which the
engaging portion extends radially outwardly and a tapered portion
extending radially inwardly from the base portion and containing
the through hole.
6. The door assembly of claim 5, wherein the auxiliary opening is
formed in the base portion.
7. The door assembly of claim 5, wherein the flange further
comprises a beaded portion on its distal end that engages the
burner fuel supply line.
8. The door assembly of claim 1, further comprising a radiation
shield mounted on the burner fuel supply line, spaced from the
flexible seal and sized to substantially block radiant heat
generated by the burner in the combustion chamber from impacting
the flexible seal.
9. The door assembly of claim 1, wherein the flexible seal is
formed from silicon based material.
10. The door assembly of claim 1, wherein the through hole in the
flexible seal is located in a folded portion extending from the
engaging portion.
11. The door assembly of claim 10, wherein the through hole is
formed in a rib extending radially inwardly from a portion of the
folded portion.
12. A water heater comprising: a water container; a combustion
chamber adjacent the water container and having an access opening;
a burner associated with the combustion chamber and arranged to
combust fuel to heat water in the water container; a control valve
that regulates fuel flow from an external fuel source; and a door
assembly comprising: 1) a door member sized and shaped to
substantially sealingly cover an access opening in a water heater
combustion chamber and having a door opening through which a fuel
line extends at least partly between a burner in the combustion
chamber and a gas control valve; and 2) a flexible seal positioned
at least partly within the door opening comprising an engaging
portion substantially sealed to an edge portion of the door
opening, and having a through hole that is shaped to receive the
fuel supply and having a size slightly smaller than the size of an
outer dimension of the fuel supply line such that the flexible seal
and the fuel supply line are friction fit together to form a seal,
the flexible seal further defining an auxiliary opening shaped to
receive one of a pilot fuel line and an electrical wire extending
through the door opening.
13. The water heater of claim 12, wherein the engaging portion has
a channel formed in a distal portion of the flexible seal and is
sized and shaped to sealingly engage the edge portion.
14. The water heater of claim 13, wherein the channel is
substantially U-shaped.
15. The water heater of claim 12, wherein the flexible seal further
comprises: a flattened, O-ring shaped flat base portion having a
diameter larger than the fuel supply line and from which the
engaging portion extends radially outwardly and a tapered portion
extending radially inwardly from the base portion and containing
the through hole.
16. The water heater of claim 15, wherein the auxiliary opening is
formed in the base portion.
17. The water heater of claim 15, wherein the flange further
comprises a beaded portion on its distal end that engages the fuel
supply line.
18. The water heater of claim 12, further comprising a radiation
shield mounted on the fuel supply line, spaced from the flexible
seal and sized to substantially block radiant heat generated by a
burner in the combustion chamber from impacting the flexible
seal.
19. The water heater of claim 12, wherein the flexible seal is
formed from silicon based material.
20. A water heater comprising: a water tank for storing water to be
heated; a combustion chamber adjacent to the water tank and defined
at least in part by a side wall that include an access opening; a
burner positioned in the combustion chamber, the burner combusting
fuel to create products of combustion for heating the stored water;
an igniter positioned in the combustion chamber adjacent the burner
to ignite the fuel; a door removably sealed to the side wall to
close the access opening, the door including a door opening; a fuel
line extending through the door opening and being connected to the
burner for the delivery of fuel to the burner; an ignitor line
extending through the door and being connected to the ignitor; and
a flexible gasket positioned in the door opening and defining a
first aperture around the fuel line to create a gasket seal between
the fuel line and the door, and a second aperture around the
igniter line to create a gasket seal between the igniter line and
the door, to seal against ingress and egress of air between an
exterior and interior of the combustion chamber.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent
application Ser. No. 12/260,259, filed on Oct. 29, 2008, the
contents of which are incorporated by reference herein.
TECHNICAL FIELD
[0002] The technology in this disclosure relates to water heaters,
particularly to water heaters that have door assemblies, such as
those for water heater combustion chambers.
BACKGROUND
[0003] Gas fired water heaters traditionally have a water container
placed above or adjacent to a combustion chamber and burner
assembly. The burner assembly is controlled by a gas control valve
which may be responsive to user input, such as a temperature
setting. The burner assembly may have a main gas line extending
from the gas control valve, through the combustion chamber wall or
door, and to the burner. Gas lines have been constructed using
various configurations and materials. By way of example, rigid
tubing has been used where possible and in some cases threaded
fittings are used to connect the rigid tubing to flexible
tubing.
[0004] It could be beneficial to provide a gas line that is simple,
compact, durable, tamper-resistant and economical to construct.
SUMMARY
[0005] We provide water heater door assemblies comprising a base
plate sized and shaped to substantially sealingly cover an access
opening in a water heater combustion chamber and having at least
one opening through which a fuel supply line extends at least
partly between a burner in the combustion chamber and a gas control
valve; and a flexible seal positioned at least partly within the
opening comprising an engaging portion substantially sealed to an
edge portion of the opening and a through hole that is shaped to
receive the fuel supply line and has a size slightly smaller than
the size of an outer dimension of the fuel supply line such that
the flexible seal and the fuel supply line are friction fit
together to form a seal.
[0006] We also provide water heaters comprising a water container,
a combustion chamber adjacent the water container and having an
access opening; a burner associated with the combustion chamber and
arranged to combust fuel to heat water in the water container; a
control valve that regulates fuel flow from an external fuel source
and a door assembly comprising a base plate sized and shaped to
substantially sealingly cover an access opening in a water heater
combustion chamber and having at least one opening through which a
fuel supply line extends at least partly between the burner and a
gas control valve; and a flexible seal positioned in the opening
comprising an engaging portion substantially sealed to an edge
portion of the opening and a through hole that is shaped to receive
the fuel supply line and has a size slightly smaller than the size
of an outer dimension of the fuel supply line such that the
flexible seal and the fuel supply line are friction fit together to
form a seal.
[0007] We further provide water heaters comprising a water
container, a combustion chamber adjacent the water and having an
access opening, a burner associated with the combustion chamber and
arranged to combust fuel to heat water in the water container; a
control valve that regulates fuel flow from an external fuel
source; and a door assembly comprising 1) a base plate sized and
shaped to substantially sealingly cover the access opening and
having at least one rounded opening through which a fuel supply
line extends at least partly between the burner and a gas control
valve, and 2) a rounded flexible seal positioned at least partly
within the opening comprising a flattened, O-ring shaped base
portion having a diameter larger than the fuel supply line, an
opening edge engaging portion having a channel sized and shaped to
sealingly engage the rounded opening that extends radially
outwardly from the base portion, and an inner flange extending
radially inwardly from the base portion and containing a through
hole that is shaped to receive the fuel supply line and has a size
slightly smaller than the size of a dimension of the fuel supply
line such that the flexible seal and the fuel supply line are
friction fit together to form a seal.
[0008] We still further provide water heaters comprising a water
container, a combustion chamber adjacent the water and having an
access opening; a burner associated with the combustion chamber and
arranged to combustion fuel to heat water in the water container, a
control valve that regulates fuel flow from an external fuel
source, and a door assembly comprising a base plate sized and
shaped to substantially sealingly cover an access opening in the
combustion chamber and having at least one opening through which a
fuel supply line extends at least partly between the burner and a
gas control valve, and a rounded flexible seal positioned at least
partly within the opening comprising: 1) an opening edge engaging
portion comprising a channel formed in a distal portion of an outer
flange extending radially outwardly from a base portion of the
flexible seal and 2) a tapered portion extending at least partly
radially inwardly from the base portion and forming a through hole
that is shaped to receive the fuel supply line and has a
size/diameter slightly smaller than the size of an outer dimension
of the fuel supply line such that the flexible seal and the fuel
supply line are friction fit together to form a seal.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 is a schematic front elevational view of a water
heater.
[0010] FIG. 2 is a schematic side elevational view of the water
heater of FIG. 1.
[0011] FIG. 3 is a schematic front elevational view of the lower
portion of a water heater of the type shown in FIG. 1.
[0012] FIG. 4 is a schematic perspective view of a water heater
door assembly taken from the water heater shown in FIGS. 1 and
3.
[0013] FIG. 5 is a schematic side elevational view, partially taken
in section, of the door assembly of FIG. 4.
[0014] FIG. 6 is a schematic perspective view of the door assembly
shown in FIG. 5.
[0015] FIG. 7 is a schematic rear view of the door assembly shown
in FIGS. 5 and 6.
[0016] FIG. 8 is a schematic perspective view, taken from below, of
a flexible seal utilized in the door assembly shown in FIGS.
5-7.
[0017] FIG. 9 is a schematic perspective view taken from above of
the flexible seal shown in FIG. 8.
[0018] FIG. 10 is a schematic perspective view, taken in section,
of another fuel line assembly.
[0019] FIG. 11 is a schematic perspective view, taken in section,
of another fuel line assembly.
DETAILED DESCRIPTION
[0020] It will be appreciated that the following description is
intended to refer to specific aspects of the representative
structures selected for illustration in the drawings and is not
intended to define or limit the technology of this disclosure,
other than in the appended claims.
[0021] Turning now to the drawings in general and FIGS. 1-3 in
particular, the number "2" designates a storage type gas water
heater 2. Water heater 2 includes jacket 4 which surrounds a water
tank 6, a main burner 14 in a combustion chamber 15. The term water
tank 6 or water container can include conventional storage type
water tanks. However, it can include other types of structures
through which water passes and/or is retained for a period of time
whether extended or just momentary. Thus, the water container can
also be as simple a structure as a pipe or conduit through which
water flows.
[0022] Passing through the center of the tank 6 is a flue 10, in
this instance incorporating a series of baffles 12 to better
transfer heat generated by the main burner 14. Water tank 6 is
preferably of mains pressure capability and is capable of holding
heated water. Water tank 6 is preferably insulated by foam
insulation 8. Alternative insulation may include fiberglass or
other types of fibrous insulation, heating retaining material and
the like. Fiberglass insulation 9 surrounds combustion chamber 15
and the lowermost portion of water tank 6. It is possible that heat
resistant foam insulation can be used if desired. A foam dam 7
separates foam insulation 8 and fiberglass insulation 9.
[0023] Located underneath the water tank 6, within the combustion
chamber 15, is the main burner 14 which uses any type of fuel such
as oil, natural gas or other gases such as LPG, for example. Other
suitable fuels may be substituted. Fuel is provided to the main
burner 14 through the main fuel line 20, which is fluidly connected
to fuel control valve 21. Fuel control valve 21 supplies fuel to
burner 14 by way of main fuel line 20. Main burner 14 combusts a
fuel and air mixture and the hot products of combustion resulting
rise up through flue 10, possibly with heated air. Water tank 6 is
lined with a glass or other type of coating for corrosion
resistance. Bottom 5 of water tank 6 is preferably coated on both
its interior facing surface 3 and exterior facing surface 11. The
thickness of the coating of exterior facing surface 11 may be about
half of the thickness of interior facing surface 3. Also, the lower
portion of flue 10 is preferably coated on both of its opposing
surfaces. The surface exposed to the flue gases has a thickness
about half the thickness of the surface exposed to water in water
tank 6. It has been discovered that the glass coating helps to
prevent scaling of the flue and water tank surfaces.
[0024] Combustion chamber 15 also contains a pilot burner 49
connected to fuel control valve 21 by pilot fuel supply line 47. A
sheath 52, preferably made of copper, containing wires (not shown)
from a flame detecting thermocouple to ensure that in the absence
of a flame at pilot burner 49 fuel control valve 21 shuts off the
gas supply. The thermocouple may be selected from those known in
the art. RobertShaw Model No. TS 750U is preferred.
[0025] FIG. 3 particularly shows main fuel line 20 and pilot fuel
supply line 47 extending outwardly from a door 25, which provides
access to the combustion chamber 15. Door 25 is removably sealable
to skirt 60 that forms the side wall of combustion chamber 15. Door
25 is held into position by a pair of screws 62 or by any other
suitable means. Pilot fuel supply line 47 and fuel supply line 20
pass through door 25 in a substantially fixed and sealed condition.
Sheath 52 also extends through door 25 in a substantially fixed and
sealed condition as does igniter line 64. Igniter line 64 connects
on one end to an igniter button 22 and a piezo igniter 66. Igniter
button 22 can be obtained from Channel Products, for example. Each
of pilot fuel supply line 47, fuel supply line 20 and sheath 52 are
removably connectable to fuel control valve 21 by compression nuts
68, 70 and 72, respectively. Each of compression nut 68, 70 and 72
are threaded and threadingly engage control valve 21.
[0026] The products of combustion pass upwardly and out the top of
jacket 4 via flue outlet 16 after heat has been transferred from
the products of combustion. The flue outlet 16 discharges
conventionally into a draft diverter 17 which in turn connects to
an exhaust duct leading outdoors.
[0027] Water heater 2 is preferably mounted on legs 24 to raise
bottom pan 26 off the floor. Bottom pan 26 preferably has one or
more apertures 27 or some other means (not shown) for receiving
combustion air. Where bottom pan 26 meets jacket 4, the mating
surfaces (made up from surfaces of bottom pan 26 and jacket 4) can
be sealed thoroughly to prevent ingress of air or any flammable gas
or vapor. The cylindrical wall of jacket 4 (the majority of gas
water heaters are cylindrical; however, a cubic or other shaped
jacket 4 may be utilized) can be sealed gas tightly so no openings
or breaks remain upon assembly and installation.
[0028] In particular, gas, water, electrical, control or other
connections, fittings or plumbing, wherever they pass through the
jacket 4 or bottom pan 26, can be sealed airtight. The joining area
of bottom pan 26 to jacket 4 and all service entries or exits to
the jacket 4 need not be sealed airtight. It is preferred, however,
that the space around burner 14 be substantially air/gas tight
except for means to supply combustion air.
[0029] Referring now to FIGS. 5-9, a representative structure of a
six degrees of freedom flexible joint (hereinafter sometimes
referred to as "flexible gasket 500" is shown. The flexible gasket
500 is positioned within an opening 102 in door 25. The opening has
an edge portion 104 which is in direct contact with flexible gasket
500.
[0030] Flexible gasket 500 includes a base portion 506 and an outer
flange 508 that extends radially outwardly from the base portion
506. The outer flange 508 has a channel 510 as particularly shown
in FIG. 8 which substantially sealingly engages edge portion 104 of
door 25. Channel 510 is preferably shaped similarly to the shape of
edge portion 104 to enhance the sealing effect. However, any number
of shape channels 510 such as U-shaped, V-shaped and the like may
be employed.
[0031] A folded portion 512 extends from base portion 506 and has a
distal end 514 as particularly shown in FIG. 9 that is shaped to
receive main fuel line 20 through a through hole 516. The diameter
of through hole 516 may be smaller than the outer diameter of main
fuel line 20. In that regard, the diameter of through hole 516 may
be slightly smaller than the diameter of main fuel line 20 so that
a friction fit between flexible gasket 500 and main fuel line 20 is
achieved. This results in a substantial seal against the ingress
and egress of air between the exterior and interior of the
combustion chamber.
[0032] In this particular structure, the diameter of through hole
516 is about the same as or--slightly larger than the outer
diameter of main fuel line 20. However, there is a radially
inwardly extending rib 517 that has an opening, the inner diameter
of which is smaller than the outer diameter of main fuel line 20.
Preferably, the diameter of rib 517 is slightly smaller than the
diameter of main fuel line 20 so that a friction fit between
flexible gasket 500 generally and rib 517 in particular, on the one
hand, and main fuel line 20, on the other hand, is achieved.
[0033] Flexible gasket 500 also has at least one auxiliary opening
518 through which a pilot fuel line (not shown in FIGS. 8 and 9,
but shown in FIG. 3 by reference number 47) can extend into the
combustion chamber from the gas control valve 21 in a similar
substantially sealed manner. Additionally, one or more electrical
wires (not shown in FIGS. 5-9, but wire 64 is shown in FIG. 3) can
extend through another auxiliary opening such as opening 519, for
example. Additional structures may extend through one or more
openings of the type such as shown by openings 118 and 119.
[0034] Flexible gasket 500 is at least partially made from a
flexible material that allows for the installation of main fuel
line 20 through flexible gasket 500 in a relatively easy manner.
Also, the flexibility of flexible gasket 500 allows for a certain
degree of float or six-way movement of fuel line 20 as shown by the
arrows labeled A and B in FIG. 5. The flexible nature of flexible
gasket 500 allows not only for movement in the directions shown by
arrows A and B, but also within a continuum of directions and
angles between arrows A and B. This is particularly advantageous
during transportation and installation wherein the water heater 2
may be "jostled." This construction allows for the relative
movement of the components of the fuel line system without damage
occurring.
[0035] Folded portion 512 can be configured in any number of shapes
and sizes, as well as numbers of folds. Although flexible gasket
500 is shown with three such folds in FIGS. 5-9, any number of
folds may be utilized. Moreover, although the folds are shown as
U-shaped folds, other shapes of folds may be used such as V-shaped
folds that substantially render the folded portion as a pleated
portion.
[0036] Referring now to FIG. 10, another representative structure
of a six degrees of freedom flexible joint (hereinafter sometimes
referred to as "flexible gasket 100") is shown. The flexible gasket
100 is positioned within an opening 102 in door 25. The opening has
an edge portion 104 which is in direct contact with flexible gasket
100.
[0037] Flexible gasket 100 includes a base portion 106 and an outer
flange 108 that extends radially outwardly from the base portion
106. The outer flange 108 has a channel 110 which substantially
sealingly engages edge portion 104 of door 25. Channel 110 is
preferably shaped similarly to the shape of edge portion 104. Thus,
any number of shaped channels 110 such as U-shaped, V-shaped and
the like may be employed.
[0038] A tapered portion 112 extends radially inwardly from base
portion 106 and has a distal end 114 that is shaped to receive main
fuel line 20 through a through hole 116. The diameter of through
hole 116 is smaller than the outer diameter of main fuel line 20.
Preferably, the diameter of through hole 116 is slightly smaller
than the diameter of main fuel line 20 so that a friction fit
between flexible gasket 100 and main fuel line 20 is achieved. This
results in a substantial seal against the ingress and egress of air
between the exterior and interior of the combustion chamber.
[0039] Flexible gasket 100 also has at least one auxiliary opening
118 through which a pilot fuel line (not shown in FIG. 10, but
shown in FIG. 3 by reference number 47) can extend into the
combustion chamber from the gas control valve 21 in a similar
substantially sealed manner. Additionally, one or more electrical
wires (not shown in FIG. 10, but wire 64 is shown in FIG. 3) can
extend through auxiliary opening 118. Additional structures may
extend through one or more openings 118.
[0040] Like flexible gasket 500, flexible gasket 100 is at least
partially made from a flexible material that allows for the
installation of main fuel line 20 through flexible gasket 100 in a
relatively easy manner. Also, the flexibility of flexible gasket
100 allows for a certain degree of "float" or six-way movement of
fuel line 20 as shown by the arrows labeled C and D in FIG. 10.
This is particularly advantageous during transportation and
installation wherein the water heater 2 may be "jostled." This
construction allows for the relative movement of the components of
the fuel line system without damage occurring.
[0041] The distal end 120 of main fuel line 20 is secured in place
by a mounting bracket 122. This can be made from a flexible
material or a non-flexible material. The material can be the same
or different from flexible gasket 100. Flexible gasket 100 may be
made from any number of materials that are heat resistant to a
temperature typical of the vicinity of water heater combustion
chambers. Also, the material should be heat resistant over extended
periods of time and should be formulated so that it will retain its
flexibility over an expected water heater service life. The
material should be selected so that it has a degree of strength to
resist easy puncture or deterioration. Silicon-based materials are
preferred although any material meeting these fundamental
guidelines is satisfactory.
[0042] Referring to FIG. 11, another representative flexible gasket
structure 200 is shown. That structure contains a radially
outwardly extending outer flange 208 that may be similar in
function and shape to the flange shown in FIG. 10. It also includes
a channel 210 in which a edge opening portion 212 engages channel
210 in a substantially sealed manner. Channel 210 may also have
various shapes such as U-shape, V-shape and the like. Flexible
gasket 200 also includes a base portion 214 that is substantially a
type of O-ring that is flattened such that its inner and outer
surfaces are substantially parallel to main fuel line 20. One end
of flange 214 has an inner flange 216 that extends radially
inwardly toward main fuel line 20. That inner flange also has a
beaded portion 218 that engages the outer surface of main fuel line
20. As was the case in FIG. 10, the beaded portion 218 has a
diameter that is preferably slightly smaller than the diameter of
the outer surface of the main fuel line 20 such that insertion of
main fuel line 20 through hole 220 of beaded portion 218 results in
a friction fit and in a substantial air-tight seal. Otherwise, the
functionality of flexible gasket 200 is substantially the same as
flexible gasket 100 as depicted in FIG. 10.
[0043] Main fuel line 20 is shown having a radiation shield 222
that is substantially, circularly shaped and is placed on the
inside of the combustion chamber. It is provided with a sufficient
size or diameter that substantially blocks radiant heat emanating
from burner 14 from directly impacting on flexible gasket 200. This
assists in extending the surface life of flexible gasket 200.
[0044] Various other sizes and shapes of flexible gaskets may be
employed. They should be fixable to the opening 102 and should
engage fuel line 20 with a friction fit arranged so that the
resulting door assembly, including fuel line 20, is substantially
sealed and resists ingress and egress of air from the combustion
chamber except by way of designated passageways.
[0045] It will be understood that water heater 2 may be constructed
with a wide variety of materials, in a wide variety of shapes and
sizes. For example, any number of types of burners 14 may be
employed, along with various types of fuel control valves 21 and
the like. Also, various types of insulation, water containers/tanks
and jackets may be employed.
[0046] Although the technology of this disclosure has been
described in connection with specific representative forms thereof,
it will be appreciated that a wide variety of equivalents may be
substituted for the specified elements described herein without
departing from the spirit and scope of this technology as described
in the appended claims.
* * * * *