U.S. patent application number 13/588937 was filed with the patent office on 2013-11-21 for sewer vent.
This patent application is currently assigned to ORC Technology Pty Ltd. The applicant listed for this patent is Bernie SIZER, Greg WILLIAMSON. Invention is credited to Bernie SIZER, Greg WILLIAMSON.
Application Number | 20130305441 13/588937 |
Document ID | / |
Family ID | 49577955 |
Filed Date | 2013-11-21 |
United States Patent
Application |
20130305441 |
Kind Code |
A1 |
WILLIAMSON; Greg ; et
al. |
November 21, 2013 |
Sewer Vent
Abstract
A sewer vent 1 including structure 3 defining a flow path along
which air entering the sewer travels upwardly past a valve element
4. The valve element is configured to sink in air to form a seal to
prevent gas escaping from the sewer, and float in water to form a
seal to prevent water entering the sewer.
Inventors: |
WILLIAMSON; Greg; (Narre
Warren North, AU) ; SIZER; Bernie; (Narre Warren
North, AU) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
WILLIAMSON; Greg
SIZER; Bernie |
Narre Warren North
Narre Warren North |
|
AU
AU |
|
|
Assignee: |
ORC Technology Pty Ltd
Narre Warren North
AU
|
Family ID: |
49577955 |
Appl. No.: |
13/588937 |
Filed: |
August 17, 2012 |
Current U.S.
Class: |
4/219 |
Current CPC
Class: |
E03F 5/08 20130101; F16K
24/00 20130101; E03F 7/04 20130101 |
Class at
Publication: |
4/219 |
International
Class: |
E03F 7/04 20060101
E03F007/04 |
Foreign Application Data
Date |
Code |
Application Number |
May 16, 2012 |
AU |
2012202851 |
Claims
1. A sewer vent including structure defining a flow path along
which air entering the sewer travels upwardly past a valve element,
wherein the valve element is configured to sink in air to form a
seal to prevent gas escaping from the sewer; and float in water to
form a seal to prevent water entering the sewer.
2. The vent of claim 1 wherein the valve element is or includes a
downwardly open vessel portion.
3. The vent of claim 1 wherein the valve element has a waist
encircled by the structure to retain the valve element.
4. The vent of claim 3 wherein the encircling structure includes or
carries a resilient portion for engaging the valve element to form
each of the seals.
5. The vent of claim 1 including an overflow relief mechanism.
6. The vent of claim 5 wherein the overflow relief mechanism
includes a mounting arrangement, by which the vent is mountable,
configured to permit the vent to be lifted by rising liquid.
7. The vent of claim 6 including a float for lifting the vent.
8. The vent of claim 6 wherein the mounting arrangement includes an
upwardly open tube in which the vent is receivable and relative to
which the vent may be so lifted.
9. The vent of claim 8 and the upwardly open tube.
Description
FIELD OF THE INVENTION
[0001] This invention relates to a sewer vent.
BACKGROUND
[0002] Typically urban water systems include two waste streams for
carrying waste water away from dwellings: a sewerage system and a
separate storm water system.
[0003] The sewerage system includes sewers for conveying waste
water from toilets and other bathroom facilities to a treatment
facility. This water carries fecal matter and other hazardous
materials and is often referred to as "sewage" or "black water". At
the treatment facility the sewage is typically treated using a
combination of mechanical, chemical and biological techniques to
sanitise the water, before the water can be discharged. Typically
the treated water is discharged to a natural body of water or
watercourse.
[0004] Storm water on the other hand typically receives little, if
any, treatment prior to being discharged. By way of example, the
storm water may simply be passed through a screen to mechanically
separate debris entrained in the water stream. Treating and
discharging storm water is thus significantly cheaper than treating
and discharging sewage. It is therefore desirable that storm water
is not directed into the sewerage system. Storm water entering the
sewer is referred to as "infiltration".
[0005] The air within a sewer system is typically pungent with
noxious gases. To prevent these noxious gases seeping into
dwellings, toilets and other bathroom fittings are fitted with
"water traps". A water trap consists of a U-shaped flow path. Water
traps are designed so that towards the end of a charge of fluid
flowing through the trap (e.g. towards the end of a toilet
flushing) air is drawn into the trap and serves to separate an end
portion of the charge. The separated charge portion is left behind
to fully occlude a lower portion of the U thereby to form a seal to
prevent the sewer gases escaping.
[0006] Despite this design intent, fluid moving along the sewer can
create a low enough pressure such that the volume of fluid left
behind in the water trap is inadequate to form a seal, or even a
portion of left behind fluid can be drawn into the sewer. This is
referred to as breaking the water trap and results in unpleasant
smells emanating from the sewer into the dwelling.
[0007] To address this problem, external vents are sometimes
provided. The vents connect the sewer to the atmosphere at a point
external to the dwelling. The vents are typically high mounted to
minimise the adverse affects of sewer gases emanating from the
vent. High mounting the vent also serves to prevent storm water
entering the sewer system via the vent, but has drawbacks in that
the elevated vent and the plumbing thereto can be unsightly and
entails costs.
[0008] Existing domestic sewer systems are typically also fitted
with an overflow relief device. Such overflow relief devices are
mounted external to the dwelling at a short distance above the
ground, e.g. some regulations specify a minimum of 75 mm (about 3
inches), but below the level of appliances internal to the
dwelling. Each overflow relief device is connected to the sewer and
comes into play if there is a downstream obstruction of the sewer.
As sewage builds up in the sewer system to the height of the
overflow relief device, it starts overflowing at this point. Thus
overflowing sewage is discharged external to the dwelling rather
than internal to the dwelling via the appliances.
[0009] The mounting of the overflow relief devices above ground
level is intended to prevent storm water entering the sewer via the
overflow relief device. This is not entirely effective. If the
contour of the ground surrounding the overflow relief device causes
storm water to accumulate and puddle about the overflow relief
device, once the puddling water reaches the height of the overflow
relief device it will enter the sewer. This problem is compounded
by the fact that ground contours can change over time. Some
nefarious individuals intentionally recountour the surrounding
ground (e.g. when a concrete driveway is installed) to direct storm
water towards the overflow relief gully when this presents them
with a lower cost option than installing appropriate storm water
drains.
[0010] It is an object of the invention to provide an improved
sewer vent, or at least to provide an alternative for those
concerned with sewer vents.
[0011] It is not admitted that any of the information in this
patent specification is common general knowledge, or that the
person skilled in the art could be reasonably expected to ascertain
or understand it, regard it as relevant or combine it in any way at
the priority date.
SUMMARY
[0012] One aspect of the invention provides a sewer vent including
structure defining a flow path along which air entering the sewer
travels upwardly past a valve element, wherein the valve element is
configured to [0013] sink in air to form a seal to prevent gas
escaping from the sewer; and [0014] float in water to form a seal
to prevent water entering the sewer.
[0015] The valve element may be or include a downwardly open vessel
portion. Preferably the valve element has a waist encircled by the
structure to retain the valve element, in which case the encircling
structure preferably includes or carries a resilient portion for
engaging the valve element to form each of the seals.
[0016] The vent preferably includes an overflow relief mechanism,
which mechanism may include a mounting arrangement, by which the
vent is mountable, configured to permit the vent to be lifted by
rising liquid. The vent may include a float for lifting the
vent.
[0017] The mounting arrangement preferably includes an upwardly
open tube in which the vent is receivable and relative to which the
vent may be so lifted.
[0018] Another aspect of the invention provides the vent and the
upwardly open tube.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] FIG. 1 is a vertical cross-section view of an exemplary
sewer vent in situ.
DESCRIPTION OF AN EMBODIMENT
[0020] FIG. 1 illustrates a sewer vent 1 received within an
upwardly opened tubular portion 2. The vent 1 and tube 2 are in use
mounted close to ground level. The tube 2 is fitted to the end of a
pipe which connects to an underlying sewer. The vent 1 is thereby
communicated with the sewer.
[0021] The sewer vent 1 includes four principal components: body
structure 3, valve element 4, elastomeric ring 5 and float 6.
[0022] The body structure 3 is made up of a top cover 3a, a centre
plate 3b and main body 3c. Preferably each of these components is,
at least predominantly, formed of PVC. The cover 3a includes a
spherically domed portion which presents a convex upper surface and
is about 3 mm thick. The cover 3a has a circular periphery when
viewed in plan.
[0023] Bosses 3d and 3e, and spigot 3f, project downwardly from an
interior of the cover 3a.
[0024] The boss 3d is tubular and mates with a vertical tubular
boss 3g extending upwardly from the centre plate 3b to define a
vertical through bore communicating a chamber 3h below the centre
plate 3b to atmosphere. The upper open end of the boss 3d
constitutes an air intake. Desirably the air intake is mounted at,
or as in this case adjacent, the very top of the vent 1 to reduce
the likelihood of being submerged.
[0025] The boss 3e carries a downwardly open blind bore and mates
with a tubular boss 3i projecting upwardly from the plate 3b. A
tubular boss 3j projects upwardly from the main body 3c and mates
with an underside of the centre plate 3b in alignment with the
bosses 3e, 3i. A screw passes through the bosses 3i, 3j to engage
the bore of boss 3e to connect the structural members 3a, 3b and
3c.
[0026] The main body 3c includes a circular horizontal base 3k from
which an annular wall 3l projects upwardly and a cylindrical wall
3m projects downwardly.
[0027] The base 3k and wall 3l together define an upwardly open
cup-like portion. The centre plate 3b sits atop a stop in the form
of an upwardly facing annular step on the interior of the wall 3l
to define the chamber 3h in the lower half of this cup-like
portion.
[0028] The upper edge of the wall 3l defines an upwardly open
groove, in which an O-ring is received, and a cylindrical inwardly
facing surface. The outer periphery of the cover 3a includes a
short downwardly projecting circular rib, co-operable with this
cylindrical surface of the wall 3l, and a downwardly facing annular
planar surface co-operable with the O-ring. Via this interface the
cover 3a sealingly engages the main body 3c.
[0029] As noted, the lower chamber 3h is communicated to the
atmosphere via the bosses 3d, 3g. The cover 3a and centre plate 3b
together define an upper chamber 3n within the upwardly open
cup-like portion of the main body 3c. The centre plate 3b has a
central circular aperture through which the lower chamber 3h is
communicable with the upper chamber 3n. The centre plate 3b and
main body 3c include co-operable tubular bosses (not shown;
analogous to the bosses 3d, 3g, which communicate the upper chamber
3n with the region 3o below the main body 3c (which is in turn in
communication with the sewer). The structure 3 thereby defines a
flow path communicating the outside environment with the sewer.
[0030] The valve element 4 is carried within the central aperture
of the centre plate 3b such that any air entering the sewer via
this flow path must move upwardly past the valve element 4 en route
from the lower chamber 3h to the upper chamber 3n.
[0031] The ring 5 has a square cross-section and an outwardly
facing annular groove about its periphery by which it is engaged
with the inner edge of the circular opening of the centre plate 3b.
The valve element 4 consists of an upwardly open cup-like portion
4a and a downwardly open cup-like portion 4b. In the described vent
1 the portions 4a, 4b are formed separately. A horizontal floor of
the portion 4a is bonded to a horizontal ceiling of the portion 4b.
The portions 4a, 4b each include outwardly diverging walls defining
a waist about the point at which the portions are bonded.
[0032] This waist is encircled by the centre plate 3b and the ring
5 such that the valve element 4 is retained in its position
intermediate the lower chamber 3h and the upper chamber 3n.
[0033] In operation of the vent 1, the valve element moves up and
down. The spigot 3f is received within the upwardly open cup-like
portion 4a at least when the element 4 is in its uppermost
position. The spigot 3f co-operates with the internal surfaces of
the inclined walls of the portion 4a to limit "cocking" (i.e. to
limit rotation about any horizontal axis) of the element 4 as it
moves upwardly.
[0034] The inclined wall of the portion 4a carries adjacent its
upper edge a sharp annular rib which projects outwardly and
downwardly at an oblique angle. When the pressure within the sewer
is equal to atmospheric conditions, the valve element will tend to
drop to its lowermost position under its own weight. For this
purpose the valve element 4 is formed of materials heavier than
air.
[0035] In its lowermost position the annular rib of the portion 4a
engages the ring 5 to form a seal. This seal serves to prevent air
and other gases escaping from the sewer via the flow path of the
structure 3. Any increase in gas pressure within the sewer (which
would otherwise tend to drive gases from the sewer) tends to drive
the valve element 4 downwardly into firmer engagement with the ring
5. Thus preferred forms of the invention have been found to
effectively limit the escape of sewer gases.
[0036] On the other hand, a reduction of pressure in the sewer
tends to lift the valve element from its lowermost position such
that a short "burp" of air enters the sewer to limit the reduction
in pressure and in turn preserve nearby water traps.
[0037] The wall of the portion 4b has a stepped profile defining an
upwardly facing annular section carrying an upwardly directed sharp
annular rib.
[0038] In the event that the vent 1 is submerged, water enters the
lower chamber 3h via the bosses 3d, 3g and begins to surround the
lower portions of the valve 4. The portion 4b, being a downwardly
open vessel, traps a pocket of air. In the described exemplary
event, the vent is formed of heavier than water materials and the
portion 4b is dimensioned to trap a volume of air sufficient to
cause the valve element 4 to float.
[0039] As water continues to accumulate in the chamber 3h, the
valve element 4 is lifted until the sharp rib of portion 4b engages
an underside of the ring 5 to form a seal. As the depth of water
above the vent 1 increases, so does the pressure in the chamber 3h,
which pressure serves to drive the sharp annular rib into further
engagement with the ring 5. Thus this exemplary vent has been found
to be effective to prevent water entering the sewer via the flow
path of the structure 3 and thus constitutes an anti-infiltration
device.
[0040] As described, the elastomeric ring 5 serves to define the
valve element's 4 upper and lower positions and to co-operate with
the valve element 4 to form a seal in each of the upper and lower
positions. In normal operation, the vent 1 functions as a check
valve to prevent gas escaping the sewer and also as a check valve
to prevent water entering the sewer.
[0041] The mounting arrangement of the vent 1 will now be
described. As will become apparent this mounting arrangement
constitutes an overflow relief mechanism.
[0042] The tube 2 has a flared upper end. The outer circular
periphery of the cover 3a is dimensioned to sit within and mate
with this flared portion. When the vent is so mounted its edges are
concealed; only the domed exterior of the cover 3a and its air
intake can be reached. These features are not readily gripped by
hand. Thus the vent is tamper-resistant.
[0043] An outwardly open annular groove encircles the wall 3l
adjacent its upper edge. This groove carries a further O-ring
configured to mate with the cylindrical interior of the tube 2 to
prevent sewer gases escaping between the tube 2 and the structure
3. The remaining portions of the vent 1 are configured to (at least
ideally) clear the tube 20.
[0044] In this example, exemplary vent 1 and tube 2 are configured
for a 1.1 mm radial clearance between the cylindrical exterior of
the portion 3m and the cylindrical interior of the tube 2. Thus the
vent 1 can be simply dropped into the tube 2.
[0045] The float 6 is carried within the region 3o defined by the
portion 3m. It also forms part of this exemplary overflow relief
mechanism. It includes an upward spigot 6a by which it is mounted
to the main body 3c. The spigot 6a is received within and engages a
tubular boss 3p projecting downwardly from the centre of the floor
3k. The float 6 is a closed air filled vessel.
[0046] The operation of the overflow relief mechanism will now be
described. During normal operation of the sewer the water level is
well below the vent 1. In the event of a downstream blockage of the
sewer, the water level may rise. In the event that it rises to the
level of the float, the float is dimensioned to provide sufficient
buoyancy to lift the vent 1. In the described exemplary vent, if
the water simply rises to, or slightly above, the level of the
float and then recedes, the vent 1 may be lifted a short distance
and then dropped to its original position once the water has
receded. Thus the vent resets itself without the need for
intervention from a user. The elevated vent also serves to provide
a visual indication of a blockage before sewage overflows.
[0047] If instead of receding the water in the sewer continues to
rise, the vent 1 is lifted further until it projects a sufficient
distance beyond the tube 2 to topple therefrom. The vent 1 is thus
fully ejected from the tube 2. As the vent 1 is fully ejected, the
full bore of the tube 2 is available to provide overflow relief.
This reduces the risk of the overflow relief being overwhelmed by a
downstream blockage such that sewage overflows from both the
overflow relief and from appliances within the dwelling.
[0048] An exemplary vent 1 and tube 2 have been described. This
exemplary arrangement should not be construed as limiting the scope
of the invention. Other variations are possible. By way of example,
it is contemplated that the downwardly open valve portion 4b could
be replaced with a lighter than water solid. Whilst it is
considered that various lighter than water solids could be
workable, the use of a downwardly open vessel is preferred. Various
low cost, lighter than water materials are thought to be at risk of
various forms of degradation. By way of example, aerated
polystyrene is thought to suffer from the interpenetration of
various solids which can affect its density.
* * * * *