Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
FLUSHING HYDRANT WITH FAIL-SAFE
FIELD
[0001] The current disclosure relates to fire hydrants. Particularly, the
current disclosure
relates to flushing of fire hydrants.
SUMMARY
[0002] A device for flushing a hydrant is disclosed and includes a stem
connected to a fluid
valve of the hydrant and an actuation system including a biased translational
system
coupled to the stem, a compressed gas, and a normally-open gas discharge
valve.
[0003] Also disclosed is an actuation system for flushing a hydrant, wherein
the actuation
system includes a fluid, a piston assembly movable by the fluid, a manual
bleed valve in
communication with the fluid, and a biasing element at least indirectly
biasing the piston
assembly towards a stop position.
[0004] Also disclosed is a method of flushing a hydrant including operating an
actuation
system coupled to the hydrant, the actuation system including a compressed
gas, a
normally-open gas discharge valve, a piston assembly coupled to a stem of the
hydrant;
and a biasing element coupled to the stem, the stem connected to a fluid valve
of the
hydrant; closing the normally-open gas discharge valve; and opening the fluid
valve of
the hydrant by pressurizing one side of a piston plate of the piston assembly
with the
compressed air.
[0005] Various implementations described in the present disclosure may include
additional
systems, methods, features, and advantages, which may not necessarily be
expressly
disclosed herein but will be apparent to one of ordinary skill in the art upon
examination
of the following detailed description and accompanying drawings. It is
intended that all
such systems, methods, features, and advantages be included within the present
disclosure
and protected by the accompanying claims.
DESCRIPTION OF THE FIGURES
[0006] The features and components of the following figures are illustrated to
emphasize the
general principles of the present disclosure and are not necessarily drawn to
scale.
Corresponding features and components throughout the figures may be designated
by
matching reference characters for the sake of consistency and clarity.
Although
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dimensions may be shown in some figures, such dimensions are exemplary only
and are
not intended to limit the disclosure.
[0007] FIG. 1 is a cross-sectional view of a standard fire hydrant.
[0008] FIG. 2 is a cross-sectional view of a flushable hydrant in accord with
one embodiment
of the current disclosure in a resting state.
[0009] FIG. 3 is a cutaway view of the flushable hydrant of FIG. 2 taken along
a different
cutting plane from FIG. 2.
[0010] FIG. 4 is a cross-sectional view of the flushable hydrant of FIG. 2 in
an actuated
position.
[0011] FIG. 5 is a perspective view of the flushable hydrant of FIG. 2 without
a shroud.
[0012] FIG. 6 is a schematic representation of a compressed gas system of the
flushable
hydrant of FIG. 2.
[0013] FIG. 7 is an exploded perspective view of the flushable hydrant of FIG.
2.
[0014] FIG. 8 is an electrical schematic of the flushable hydrant of FIG. 2.
[0015] FIG. 9 is an electrical schematic of one embodiment of a flushable
hydrant.
[0016] FIG. 10 is a flow diagram showing an embodiment of a method for
operating the
flushable hydrant of FIG. 9.
[0017] FIG. 11 is a state diagram showing an embodiment of the various states
when the
flushable hydrant of FIG. 9 is operated.
[0018] FIGS. 12A-12C are timing diagrams showing examples of timing
characteristics of
the operation of the flushable hydrant of FIG. 9.
[0019] FIG. 13 is a side view of one embodiment of a flushable hydrant without
a shroud.
DETAILED DESCRIPTION
[0020] Disclosed are methods, systems, and apparatus associated with flushing
fire hydrants.
The disclosure provides apparatus, methods, and systems for flushing a fire
hydrant. The
fire hydrant in various embodiments may be flushed using a fluid actuation
system. The
fire hydrant in various embodiments may be flushed from a remote location
using a
remote communicator.
[0021] It is common in municipal water systems to flush water through fire
hydrants to
ensure adequate flow and pressure to the hydrants and to remove sediment from
the
piping system. Often, this can be a labor-intensive task, requiring
technicians to go into
the field to perform the flushing operation for each hydrant in the piping
system.
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[0022] Most standard fire hydrants in the United States of America and in many
other parts
of the world are "dry barrel hydrants," meaning that the hydrant itself
contains no water.
Because fire hydrants are above-ground apparatus, a hydrant full of water
could freeze
and crack. Instead, water is flushed into the hydrant when it is needed.
[0023] Standard fire hydrants, such as standard fire hydrant 10, seen in FIG.
1, contain a stem
12 that connects to a fluid valve 14 in a shoe 16. The shoe 16 is connected to
a lower
barrel 17. The lower barrel 17 is connected to the upper barrel 18. The upper
barrel 18 is
connected to a bonnet 24. A nozzle 27 is also seen on the upper barrel 18. The
shoe 16 is
in fluid communication with a water supply system, which is typically a
municipal water
supply. When water is needed or when the standard fire hydrant 10 needs to be
opened to
flush the water system, an operating nut 31 attached to the stem 12 is
actuated to open the
valve 14, thereby allowing water to flow into the lower barrel 17 and the
upper barrel 18.
A nozzle cap 26 can be removed to allow water to flush through the standard
fire hydrant
or to provide water for firefighting or for other purposes. Typically, when a
flushing
operation is desired, a diffuser is connected to the nozzle 27 to reduce the
velocity of the
water stream exiting the standard fire hydrant 10, although a diffuser may not
be
necessary in all applications.
[0024] FIG. 2 is a cross-sectional view of a flushable hydrant 100 in accord
with one
embodiment of the current disclosure. The flushable hydrant 100 of the current
embodiment includes an assembly of various pieces that permits electronic
flushing of the
flushable hydrant 100. In various embodiments, the flushable hydrant 100
includes an
actuation system that includes a biased translational system for automated
opening while
maintaining a rotational manual override.
[0025] Seen in FIG. 2, much like a standard fire hydrant, the flushable
hydrant 100 includes a
stem 110 that communicates with a fluid valve (not shown) to allow water to
flush from a
lower barrel (not shown) of a hydrant body 115 into an upper barrel 118 of the
hydrant
body 115. To do this, an operating nut 120 is rotated thereby causing
actuation of the
stem 110. The operating nut 120 includes an interface portion 122 and a body
portion
124. The body portion 124 includes a cavity 126, which includes internal
threading 128.
The internal threading 128 interacts with a plunger assembly 130. The plunger
assembly
130 includes a threaded actuator 132 sheathing a piston 134. The threaded
actuator 132 is
not mechanically coupled to the piston 134 but instead is allowed to move
freely up and
down in the current view. The threaded actuator defines a square bore 133 and
has a
contact end 131. The square bore 133 is square in cross-section. The piston
134 includes
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an upper portion 136 and a lower portion 138. The lower portion 138 defines a
bore 139,
which will be discussed later. Although only a cross-sectional view is shown,
the upper
portion 136 is square in cross-section so that the threaded actuator 132 does
not rotate
when the operating nut 120 rotates. Instead, the threaded actuator 132
translates
downward in the current view thereby manually opening the fluid valve (not
shown). A
coupling countersink 111 is seen in the stem 110. The lower portion 138 fits
into the
coupling countersink 111 and is shown inserted therein. The stem 110 defines a
bore 112.
A coupling shear pin 142 is inserted through both the bore 112 and the bore
139 to couple
the plunger assembly 130 with the stem 110.
[0026] The foregoing paragraphs describe a manual override system of the
flushable hydrant
100 that allow the flushable hydrant 100 to be operated externally by an
operator such as
a fireman or technician. As such, the flushable hydrant 100 can be used in the
same
application as prior art fire hydrants. However, the flushable hydrant 100 is
also operable
by other means, as described below.
[0027] Coupled to the stem 110 is a top stop 144. The top stop 144 provides
bracing for one
end of a biasing element 146. In the current embodiment, the biasing element
146 is a
helical spring, although it may be various types of biasing elements in
various
embodiments, including various types of springs, magnetic biasing,
electromechanical
biasing such as servomotor-actuation, electromagnetic biasing such as solenoid-
actuation,
and gravitational biasing, among others. The biasing element 146 is braced on
its other
end to a bottom stop 148. Because the top stop 144 is coupled to the stem 110,
the biasing
element 146 biases the flushable hydrant 100 to the closed position, as shown
in FIG. 2.
[0028] As can be seen, the flushable hydrant 100 includes a shroud 149. The
shroud 149 of
the current embodiment is made of steel that is 0.100 inches in thickness,
although
various materials and thicknesses may be used in various embodiments. The
flushable
hydrant 100 includes six compressed gas containers 150a-f (150b, c, d, e not
shown). For
example, the gas containers 150a-f may contain compressed air. In various
embodiments,
various numbers, shapes, and configurations of compressed gas containers 150
may be
used. In one exemplary embodiment, the shroud 149 is used as a compressed gas
container 150 such that compressed gas fills the entire volume encompassed by
the
shroud. Such a configuration would obviate the need for separate compressed
gas
containers 150. Other fluid media may be used in the system of the current
embodiment
aside from compressed gas. Compressed gas is intended solely as an exemplary
embodiment. Additionally, myriad variations on the systems, methods, and
apparatus of
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the current embodiment may be used in various embodiments, including
variations that
may obviate the need for a fluid system, in some embodiments.
[0029] Each compressed gas container 150a-f is designed to hold a
predetermined volume of
compressed gas at a predetermined pressure. All of the compressed gas
containers 150a-f
are in fluid communication with one another such that the compressed gas
containers
150a-f act as a single container, although various embodiments may include
various
different configurations.
[0030] Fittings 152a-f provide a fluid communication route from each
compressed gas
container 150a-f to gas bores 154a-f in a hydrant seal plate 155,
respectively. Each fitting
152a-f in the current embodiment is made of brass, although other materials or
configurations may be used. Each gas bore 154a-f is in fluid communication
with a vein
156a-f, respectively, which connects to an annulus groove 158. Because all of
the veins
156a-f are in fluid communication with the same annulus groove 158, compressed
gas
may move between the compressed gas containers 150a-f to equalize pressure
therein.
Annular gaskets 162a, b are seen sealing the annulus groove 158.
[0031] A hold down assembly 160 includes a hold down nut 164 and a stem body
166. The
hold down nut 164 is connected by threading 167 to threading 169 of the stem
body 166.
The hold down assembly 160 sandwiches a bonnet 170 of the flushable hydrant
100. The
connection of the hold down assembly 160 and the bonnet 170 is sealed by a
gasket 171.
[0032] The stem body 166 defines a bias cavity 168 inside which the previously-
mentioned
biasing element 146 is seated. The stem body 166 also defines a pressure
cavity 175.
Within the pressure cavity 175 is a piston assembly 180. The piston assembly
180
includes a piston plate 182, a washer 184, a washer stop 186, a cylinder body
188, a
bottom plate 189, and a bottom plate stop 187. In some embodiments, the bottom
plate
189 and cylinder body 188 may be one piece. Annular gaskets 191a, band 192a, b
seal
the space between the piston plate 182 and the bottom plate 189. Piston
gaskets 194a, b
seal a chamber 199 defined within the space between the piston plate 182 and
the stem
body 166 on the opposing side of the piston plate 182 from the bottom plate
189. The
chamber 199 as shown has no volume. When the piston plate 182 moves, the
chamber
199 becomes larger. The purpose of the piston gaskets 194a, b will become
apparent
below with reference to FIG. 3.
[0033] A gas intake port 196 can also be seen connected to the top of
compressed gas
container 150a. The gas intake port 196 allows the compressed gas containers
150a-f to
be filled with compressed gas.
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[0034] As seen in FIG. 3, the cutting plane of the flushable hydrant 100 is
orthogonal to the
cutting plane of FIG. 2. A pressure regulation assembly 310 can be seen in the
current
view. An annulus connection line 315 connects through a bore in the hydrant
seal plate
155 to the annulus groove 158. As such, the annulus connection line 315 is in
fluid
communication with the annulus groove 158. The pressure regulation assembly
310 also
includes a chamber line 325 that connects through a fitting 327 to the stem
body 166.
The stem body 166 includes a gas intake port 410 (not shown) leading to the
chamber
199. A proximity sensor 335 can be seen in the pressure cavity 175. The
pressure
regulation assembly 310 also includes other features and apparatus (as will be
described
below) that allow the regulation of pressure through the pressure regulation
assembly
310. The pressure regulation assembly 310 controls the amount of gas that
flows from the
annulus connection line 315 to the chamber line 325.
[0035] In operation, the flushable hydrant 100 can be actuated using the
manual process
described above. The flushable hydrant 100 can also be actuated by an
actuation system.
The actuation system may be connected to a remote communicator in various
embodiments. One embodiment of an actuation system is described below,
although one
of skill in the art would understand that various elements may be altered or
substituted in
various modifications to the disclosure below without being considered outside
the scope
of the disclosure.
[0036] The stem 110 is capable of automatic actuation using the actuation
system. The
actuation system includes energy stored in the form of compressed gas,
although various
forms of stored energy may be used in various embodiments, including
batteries, biasing
elements such as springs and elastic, stored gravitational energy, mechanical
batteries and
flywheels, shape memory energy, and electromechanical storage, among other
types of
stored energy. Actuating the stem 110 using compressed gas is controlled by
the pressure
regulation assembly 310. The pressure regulation assembly 310 may include a
wireless
communication module or another communication module in various embodiments.
The
pressure regulation assembly 310 receives instructions to open the flushable
hydrant 100.
In response, the pressure regulation assembly 310, which is connected in fluid
communication by the annulus connection line 315 to the annulus groove 158.
The
annulus groove 158 is connected to each vein 156a-f. Each vein 156a-f is
connected to
each gas bore 154a-f. Each gas bore 154a-f is connected to by each fitting
152a-f to each
compressed gas container 150a-f. The chamber line 325 connects the pressure
regulation
assembly 310 in fluid communication to the chamber 199. Thus, the pressure
regulation
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assembly 310 controls the release of compressed gas from the compressed gas
containers
150a-f to the chamber 199.
[0037] In operation, the pressure regulation assembly 310 is opened to allow
compressed gas
to travel from the compressed gas containers 150a-f to the chamber 199. As
pressure of
the compressed gas in the compressed gas containers 150a-f is released into
the chamber
199, the increased pressure in the chamber 199 is applied to the surface area
of the piston
plate 182. Pressure applied to an area creates a force on the piston plate 199
which is
translated into the washer 184 and, thereby, into the washer stop 186. The
force on the
washer stop 186 is translated into the stem 110 resulting in a downward force
on the stem
110.
[0038] As the compressed gas flowing from the compressed gas containers 150a-f
to the
chamber 199 increases, the downward force on the stem 110 increases.
Eventually, the
force on the stem 110 overcomes the closing pressure of the fluid valve (not
shown),
causing the valve to open. When the valve opens, water is allowed to flush
into and
through the flushable hydrant 110. As such, the actuation system operates as a
biased
translational system in the current embodiment. Various embodiments of biased
translational systems may also be used in various embodiments.
[0039] To open the fluid valve, the stem 110 moves downward as shown in FIG.
4. In the
current view, the gas intake port 410 can be seen in the chamber 199. The
proximity
sensor 355 (not shown) is covered by the piston plate 182 which causes the
pressure
regulation assembly 310 to close the gas pathway from the compressed gas
containers
150a-f to the chamber 199.
[0040] As can be seen, the biasing element 146 has compressed, thereby storing
energy. The
top stop 144 has moved downward in the view because it is connected to the
stem 110, as
is the coupling shear pin 142, the piston plate 182, the washer 184, and the
washer stop
186. In the current embodiment, all of these parts have moved until the piston
plate 182
contacts the cylinder body 188 and the cylinder body 188 provides a mechanical
stop.
Other embodiments many include various configurations for stops. It should be
noted that
no other parts or subassemblies of the flushable hydrant 100 have moved in the
current
embodiment, although various configurations may be present in various
embodiments.
[0041] FIG. 5 shows a perspective view of the flushable hydrant 100.
Compressed gas
containers 150a, b, f can be seen in the view (150c, d, e are hidden from
view). A battery
510 is held in place by a battery bracket 515. A gas intake valve 520 and a
gas discharge
valve 525 can be seen. Although the gas intake valve 520 and the gas discharge
valve 525
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are used in the current embodiment, various types of pressure regulation
mechanisms,
systems, and methods may be used in various embodiments. Between the gas
intake valve
520 and the gas discharge valve 525 is a tee joint 530. The tee joint 530 is
connected on
one side to the gas intake valve 520, on one side to the gas discharge valve
525, and on
one side to the chamber line 325 (shown in FIG. 3). The gas intake valve 520
and gas
discharge valve 525 control the system.
[0042] Before any flushing takes place, pressure in the compressed gas
containers 150a-f is at
its highest, and there is no pressurization in the chamber 199. To open the
fluid valve (not
shown), as previously described, the gas discharge valve 525 closes and the
gas intake
valve 520 opens. As such, the pressure in the chamber 199 increases until the
force
exerted on the piston plate 182 overcomes the closing pressure of the fluid
valve (not
shown) at which point the fluid valve opens. As previously described, pressure
in the
compressed gas containers 150a-f is much greater than necessary to open the
fluid valve
(not shown). As such, when the proximity sensor 355 recognizes that the piston
plate 182
has moved to open the fluid valve (not shown), the gas intake valve 520
closes. This
feature helps preserve compressed gas (e.g., compressed air) in the compressed
gas
containers 150a-f because it may not be necessary for the pressure to equalize
fully from
the compressed gas containers 150a-f to the chamber 199 in order to open the
fluid valve
(not shown). Preserving compressed gas allows more flushing cycles to occur
without
refilling the compressed gas containers 150a-f. In some embodiments, the gas
intake
valve 520 and gas discharge valve 525 may each be configured to include a
solenoid,
which physically opens or closes a pneumatic valve in response to electrical
input. In
addition to a solenoid, the gate intake valve 520 and gas discharge valve 525
may also
include a gas intake port (e.g., gas intake port 196) and a gas discharge
port, respectively.
For example, the gas intake port may lead into the chamber 199 and the gas
discharge
port may lead into the surrounding environment.
[0043] Once water flushes into the flushable hydrant 100, the pressure inside
the upper barrel
118 equalizes with the system pressure. Thus, water in the system provides no
closing
pressure on the fluid valve (not shown). Instead, closing pressure on the
fluid valve is
provided by the biasing element 146, which becomes compressed due to the force
on the
piston plate 182.
[0044] When it is desired to close the fluid valve, the gas discharge valve
525 is opened
while the gas intake valve 520 remains closed. The exhaust line 535 vents to
outside air.
Without closed pressure in the chamber 199, compressed gas is allowed to flow
through
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an exhaust line 535 that is connected to the gas discharge valve 525. The
pressure in the
chamber 199 is released, thereby relieving the downward force on the piston
plate 182.
The release of the downward force allows the biasing element 146 to lift the
stem 110
and, thereby, to close the fluid valve.
[0045] FIG. 6 displays a schematic representation of the compressed gas system
of the
flushable hydrant 100. In the current embodiment, the compressed gas
containers 150a-f
are in fluid communication with each other and are connected to the gas intake
valve 520.
The gas intake valve 520 maintains any compressed gas in the compressed gas
containers
150a-f until operation of the flushable hydrant 100 is desired as described
above. When
the flushable hydrant 100 is operated, the gas discharge valve 525 closes and
the gas
intake valve 520 opens. This allows compressed gas to flow into the chamber
199. When
the proximity sensor 335 is activated as described above, the proximity sensor
335 sends
a signal to the gas intake valve 520 to close, cutting the flow of compressed
gas from the
compressed gas containers 150a-f to the chamber 199. When it is desired to
return the
flushable hydrant 100 to resting state, the gas discharge valve 525 is opened,
allowing
compressed gas in the chamber 199 to escape and to exhaust.
[0046] An exploded view of the flushable hydrant 100 is seen in FIG. 7. In
addition to
features of the current embodiment that have already been mentioned, the
exploded view
of the flushable hydrant 100 also shows bolts holding the flushable hydrant
100 together,
among other various features.
[0047] An electrical schematic can be seen in FIG. 8. The electrical schematic
of FIG. 8 is
but one method of compiling the circuitry to achieve the desired result, and
one of skill in
the art would understand that variations to such an arrangement may be
possible in
various embodiments.
[0048] In the current embodiment, each of the gas intake valve 520 and the gas
discharge
valve 525 are operational as electrical latching solenoids, although various
types of
pressure regulation mechanisms may be present in various embodiments. The gas
intake
valve 520 and the gas discharge valve 525 may be normally closed in some
embodiments.
In various embodiments, the gas discharge valve 525 may be normally open.
[0049] A first isolator 810 and second isolator 820 provide circuit isolation
depending on the
direction of current into the system. When current flows in one direction, one
circuit is
activated; when current flows in the opposite direction, another circuit is
activated. As
such, the electrical configuration of the current embodiment does not operate
both the gas
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intake valve 520 and the gas discharge valve 525 at the same time, although
one of skill
in the art would understand that a simple modification would allow such a
configuration.
[0050] A switch 830 is controlled by the first isolator 810. Switches 830,840
are electrical
switches in the current embodiment, such as transistors. Various embodiments
may
include variations of switches, including both electrical and mechanical
switches. When it
is desired to open the gas intake valve 520, current flows through the first
isolator 810
and closes the switch 830, allowing current to flow across the switch 830. The
current is
allowed to flow through the proximity sensor 335 when the proximity sensor 335
is not
activated. In other words, the proximity sensor 335 is normally shorted. The
flowing
current activates the gas intake valve 520, causing it to open, as described
above. The first
isolator 810 receives a feedback from the circuit to remain on so long as the
proximity
sensor 335 is shorted. This action provides the electrical latching of the
solenoid in the
gas intake valve 520.
[0051] As described above, the opening of the gas intake valve 520 causes the
piston plate
182 to travel in front of the proximity sensor 335. When this occurs, the
proximity sensor
335 is activated and provides an open in the circuitry. The feedback to the
first isolator
810 is cut, and the switch 830 opens, deactivating the gas intake valve 520
and returning
the solenoid in the gas intake valve 520 to its normally closed position.
[0052] When it is desired to open the gas discharge valve 525, current flows
the opposite
direction and activates the second isolator 820, thereby closing a switch 840
and allowing
current to flow to the gas discharge valve 525. Because no proximity sensor is
used with
the gas discharge valve 525, the system simply opens the gas discharge valve
525 for a
preset duration using an RC (resistor-capacitor) configuration. In the current
embodiment,
the duration that the gas discharge valve 525 is opened is a few seconds,
although various
time durations may be used in various embodiments. Once the timing of the RC
current
has expired, the switch 840 opens, stopping current flow to the gas discharge
valve 525.
When power to the solenoid of the gas discharge valve 525 is stopped, the gas
discharge
valve 525 returns to its normally closed position. Various electronic circuits
that are
shown but not described would be understood by one of skill in the art.
[0053] FIG. 9 illustrates a schematic circuit diagram of a control circuit 900
according to
various implementations of the present disclosure. The control circuit 900 is
considered
to be an alternative to the circuit of FIG. 8. One of ordinary skill in the
art may
understand that certain modifications can be made to the control circuit 900
without
departing from the spirit and scope of the present disclosure. As arranged in
FIG. 9, the
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control circuit 900 may be configured to control the operations of the
flushable hydrant
100. The control circuit 900 may be contained on a printed circuit board or
other suitable
board. The control circuit 900 is configured to be connected to a
communication device
(e.g., a communication circuit board) that can receive a wireless signal from
a wireless
network, wherein the wireless signal includes instructions to start a flushing
cycle or stop
a flushing cycle. The control circuit 900 is also configured to be connected
to the
solenoids of the gas intake valve 520 and gas discharge valve 525 and to the
proximity
sensor 335.
[0054] In response to the flushing instruction signals from the communication
device, the
control circuit 900 controls the air pressure in the chamber 199 by switching
the solenoid
valves. According to some embodiments, the control circuit 900 contains a
failsafe
arrangement such that if power to the control circuit 900 is lost, the
solenoid valves return
to their steady state or rest conditions. For example, at rest, the gas
discharge valve 525
may remain in an open state to release any residual gas pressure and the gas
intake valve
520 may remain in a closed state to preserve pressurized gas in the gas
container 150.
[0055] The package components of the control circuit 900 shown in the circuit
diagram of
FIG. 9 include a microcontroller 910, an opto-isolator 912, a debug device
914, an
external connector 916, a shorting jumper 918, a first driver 920, a second
driver 922, and
a voltage regulator 924. The circuit also includes resistors, capacitors,
inductors, diodes,
LEDs, and other electrical components used in a manner that will be understood
by one of
skill in the art.
[0056] The voltage regulator 924 is connected to a 12-volt power supply (e.g.,
a battery or
battery pack) and regulates a 3.3-volt power signal for operating the digital
components
of the circuit. The shorting jumper 918 may be configured to close a break in
the circuit.
The debug device 914 (e.g., JTAG or other suitable debugger) may include one
or more
plugs, solder joints, pads, etc. to enable the debugging of the
microcontroller 910 or
joints. The debug device 914 includes at least an I/O line and a clock line
connected to
the microcontroller 910. When the control circuit 900 is in a sleep state, the
shorting
jumper 918 is able to force the control circuit 900 into an awake state to
enable a
technician to debug the device if needed.
[0057] The external connector 916 includes 12 pins, labeled 1-12. Pins 1-8 are
configured
for receiving inputs from external sources and pins 9-12 are configured for
providing
outputs to the external sources. Pins 1 and 3 are connected to the positive
terminal of one
or two 12-volt power supplies (e.g., from batteries or other external sources)
for
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supplying 12 volts to the control circuit 900 where needed. Pins 2, 4, and 8
are connected
to the negative or ground terminal of the 12-volt power supply and may be
grounded.
Pins 5 and 6 are connected to the communication device, which may be housed on
the
flushing hydrant 100. Pin 7 is connected to a sensor. Pins 9 and 11 are supply
voltage
outputs for the solenoid valves. Pin 10 is connected to a first solenoid valve
configured to
control air intake and pin 12 is connected to a second solenoid valve
configured to control
air discharge. Pins 5, 6, and 7 are primarily input pins for receiving control
signals and
sensor signals. Pins 10 and 12 are primarily output pins for providing control
signals to
the first and second solenoid valves.
[0058] The input pins 5 and 6 may be configured to receive bi-directional
control signals
from the communication device or other external control circuit. The external
control
circuit may include an H-bridge or other type of device for providing bi-
directional
controls. The external control circuit is configured to provide a current in
one direction as
a request to start a new flush cycle and provide a current in the other
direction as a request
to stop the flush cycle. For example, a positive current from pin 5 to pin 6
(phase_A to
phase_B) indicates a flush start request, whereas a negative current from pin
5 to pin 6
(phase A to phase B) may indicate a flush stop request.
[0059] The opto-isolator 912 includes input pins 1-4 and digital output pins
Y1 and Y2.
When there is a positive voltage between pins 1 and 2, the opto-isolator 912
responds by
providing a digital output along pin Yl, which is referred to herein as a
"flush_start"
signal. The flush_start signal is sent to input pin 7 of the microcontroller
910. Also,
when there is a negative voltage between pins 3 and 4, the opto-isolator 912
responds by
providing a digital output along pin Y2, which is referred to herein as a
"flush_stop"
signal. The flush_stop signal is sent to input pin 8 of the microcontroller
910.
[0060] As mentioned above, pin 7 of the external connector 916 is connected to
receive an
input from a sensor. The sensor may be a proximity sensor (e.g., proximity
sensor 335)
or other type of sensor for detecting the presence of an object. In this case,
the sensor
detects when the piston plate 182 has been forced down to a certain position
to such an
extent that the fluid valve 14 opens. In response to sensing the presence of
the piston
plate 182, the sensor sends a positive signal, which is received on pin 7 of
the external
connector 916 and provided to pin 6 of the microcontroller 910.
[0061] Therefore, the microcontroller 910 is configured to receive input
signals from the
proximity sensor and also receive input signals for flush_start and
flush_stop. In response
to these inputs, the microcontroller 910 is configured to control the various
states of the
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flushing hydrant 100, as explained in more detail below with respect to the
state diagram
of FIG. 11. The microcontroller 910 controls the states of the flushing
hydrant 100 by
providing certain output signals as explained in more detail below with
respect to the
timing diagram of FIG. 12.
[0062] The microcontroller 910 may include a microprocessor or other suitable
type of
processing device. The microcontroller 910 may be configured to monitor
various
conditions and provide logic and timing functionality. Based on various
conditions,
logic, and timing parameters, the microcontroller 910 may be configured to
control the
drivers 920 and 922.
[0063] For example, the microcontroller 910 provides an output to the first
driver 920, which
controls the gas intake valve 520. The microcontroller 910 also provides an
output to the
second driver 922, which controls the gas discharge valve 525. Signals sent to
the drivers
920 and 922 may also illuminate LEDs 924 and 926, respectively, which may be
used for
indicating the status of the drivers (and solenoids) to a person near the
flushing hydrant
100. When a positive signal is received from the microcontroller 910, the
first driver 920,
in some embodiments, may provide a 12-volt signal to pin 10 of external
connector 916
leading to the solenoid of the gas intake valve 520. Likewise, when a positive
signal is
received from the microcontroller 910, the second driver 922, in some
embodiments, may
provide a 12-volt signal to pin 12 of external connector 916 leading to the
solenoid of the
gas discharge valve 525. Thus, the solenoids may be powered by the 12-volt
signals. In
other embodiments, the drivers 920 and 922 may be configured to create a short
to ground
in order to activate the solenoids.
[0064] The control circuit 900 may include the following specifications. The
battery power
input and auxiliary power input are nominally 12 volts, but may range from
about 11-14
volts. The quiescent/standby current is nominally 25 11A, but may have a
maximum of 35
pA. The operating current is 5 mA (nominal) and 15 mA (maximum). The solenoid
coil
current is 0.80 amps (nominal) and 1.00 amps (max). The solenoid coil
equivalent circuit
has an impedance of 13 ohms + 55 mH (nominal) and 13 ohms + 70 mH. The
solenoid
driver avalanche protection is 0.050 joules (nominal) and may range from 0.030
to 0.100
joules. The solenoid driver has short circuit protection. The operating
temperature may
range from -30 degrees Celsius to 70 degrees Celsius.
[0065] FIG. 10 illustrates a method 1000 for operating the flushable hydrant
100 according to
various embodiments of the present disclosure. In some embodiments, the method
1000
may be executed by the microcontroller 910 or by some or all of the components
of the
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control circuit 900. The method 1000 starts when the "flush start" signal is
received. As
shown, the method includes closing an air discharge valve (e.g., gas discharge
valve 525)
as described in block 1002 so that any air pressure applied to the chamber
(e.g., chamber
199) will not escape. Then, the method waits for a certain delay time (step
1004). After a
short wait (e.g., about one second), the method includes opening an air intake
valve (e.g.,
gas intake valve 520) as indicated in block 1006. Opening the air intake valve
allows air
from the compressed air tank(s) (e.g., gas containers 150) to enter the
chamber 199 and
build up pressure. When the air pressure is great enough, the pressure will
force the
piston (e.g., piston plate 182) in a certain direction. When the air intake
valve is opened,
the method further includes starting a first timer, as indicated in block
1008. The timer
Ti is used to monitor the time that it takes the air pressure to force the
piston into a
position where the fluid valve is opened to allow the hydrant to be flushed.
[0066] The method of FIG. 10 also includes determining whether or not a
"flush_stop" signal
is received (step 1010). If such a signal is received, the method branches off
to block
1030 to begin a shutdown routine. If no "flush_stop" signal is received, the
method
proceeds to decision block 1012, which determines whether the timer Ti is
greater than
five seconds. Thus, if the compressed air tanks do not provide adequate
pressure to force
the piston so as to open the fluid valve within the designated time, then the
pressurization
stage is aborted and the method skips to block 1030 to begin the shutdown
routine. If five
seconds has not been reached, the method proceeds to decision block 1014. As
indicated
by this block, the method includes the step of determining whether or not some
type of
flush indication is received from the sensor (e.g., proximity sensor 335). For
example, if
the sensor detects that the position of the piston has been moved to such a
location that
the fluid valve is opened, then it is known that the air pressurization
routine has
successfully pressurized the chamber 199 so as to open the fluid valve. As
such, the
method proceeds from the air pressurization stage and moves to a flush stage,
which
starts, for example, with block 1016. However, if no flush indication is
receives at step
1014, the method loops back to decision block 1010.
[0067] As indicated in block 1016, the method includes the process of closing
the air intake
valve. This valve is closed because at this point the chamber is adequately
pressurized
and more pressurized air is not needed. As indicated in block 1018, a second
timer T2 is
started. This timer records the time that the hydrant is maintained in a
flushing condition.
The method then proceeds to decision block 1020, which suggests that a
determination is
made as to whether or not a "flush_stop" signal is received. If so, the method
skip ahead
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to block 1030 to begin the shutdown routine. If no such signal is received,
the method
goes to decision block 1022 and it is determined whether the second timer is
greater than
a predetermined flush time. In this example, the predetermined flush time is
30 minutes.
If the hydrant has been flushing for at least 30 minutes, then the method
jumps to block
1030 to begin the shutdown routine. If less than 30 minutes, the method
proceeds to
decision block 1024. At this point, it is determined whether or not a flush
indication is
still being received from the sensor. If the sensor is still indicating that
the hydrant is in
the flush mode, the method returns back to decision block 1020 to continuing
check the
three conditions described in blocks 1020, 1022, and 1024. If the sensor no
longer
indicates that the hydrant is flushing in step 1024, the method goes to block
1026.
[00681 Block 1026 indicates that the second timer T2 is stopped. In some
embodiments, the
T2 time may later be resumed from where it left off after the flushing begins
again. In
this way, the total flushing time (even if interrupted) can be monitored. In
various
embodiments, the T2 time may be reset so that the flushing time is only for a
continuous
interrupted amount of time. In step 1028, the first timer Ti is reset and the
method
returns back to block 1006 to begin the pressurization stage again. For
example, if it is
determined that the hydrant is not flushing, the air pressure should be re-
applied to open
up the fluid valve again to continue the flushing cycle.
[00691 The shutdown routine of the method begins with block 1030. The method
opens the
air discharge valve to release the air pressure in the chamber, which allows a
biasing
member 146 to force the piston back to its rest state and closes the fluid
valve. Step 1032
includes closing the air intake valve, if it has not already been closed in a
previous step.
Also, the method includes entering a sleep mode (step 1034) and ending the
flush routine.
[0070] FIG. 11 illustrates a state diagram 1100 indicating the states of
operation for the flush
system. In some embodiments, the states may be controlled by the
microcontroller 910
shown in FIG. 9. As shown, the state diagram 1100 includes a first state
represented as a
"sleep" state 1102 when the electrical components are in a low-power mode for
conserving power. For example, the sleep state 1102 may consume about 25 to 35
iu,A
from the +12V power source. In the sleep state 1102, the solenoid for the gas
discharge
valve 525 may maintain the valve in an open or "venting" condition such that
air in the
chamber is exposed to ambient air and the pressure in the chamber is equalized
with the
environment. The solenoid for the gas intake valve 520 may maintain the valve
in a
closed state such that the pressurized air in the tanks is conserved in the
tanks. The
system remains in the sleep state 1102 until a flush start signal is received,
which wakes
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up the system to begin a new flush cycle. The system may also awaken from a
forced wake signal.
[0071] When awakened, the system moves to a "prefill" state 1104. The prefill
state 1104
precedes a state when the chamber is actually filled with pressurized air. In
the prefill
state 1104, the normally-open gas discharge valve 525 is closed, thereby
pneumatically
sealing the chamber to enable pressurization. The system remains in the
prefill state 1104
for a short time (e.g., about one second) to allow the gas discharge valve 525
to close for
sealing the chamber. Then the system moves to a "fill" state 1106.
[0072] The fill state 1106 includes opening the normally-closed gas intake
valve 520. With
the chamber 199 sealed, pressurized air from the gas cylinders 150A-F may
enter the
chamber to build the air pressure. In the fill state 1106, the sensor 335
detects when the
piston 180 has been moved to such a position that the fluid valve is opened.
Before the
piston reaches this point, indicating that the air pressure has not yet forced
the piston far
enough, the air pressure continues to build in the chamber. The system also
determines if
the sensor does not assert within a certain amount of time that would normally
be needed
for the intake air to pressurize the chamber. For example, the pressurization
time may be
about five seconds. Not being able to pressurize within this period may be an
indication
of a problem and the system may move from the fill state 1106 to the
"shutdown" state
1110 as described below. Otherwise, if the sensor senses the presence of the
piston in a
position that indicates that the fluid valve is open and the hydrant is
flushing, then the air
intake valve may be closed and the system moves to the "flush" state 1108. The
flush
state 1108 may also be referred to as an "open" state to indicate that the
fluid valve is
open and the system is flushing.
[0073] When it is determined that flushing has begun and the air intake has
been closed, no
more air is needed for pressurization. Even with the air intake closed, the
pressurized air
in the chamber remains pressurized (unless there is a leak in the system). The
constant
pressure keeps the piston in the down position thereby keeping the fluid valve
open. The
hydrant continues to flush during the flush state 1108. The system may leave
the flush
state 1108 in response to multiple different conditions. If a "flush stop"
signal is
received, indicating that the flushing cycle is to stop, then the system moves
to the
shutdown state 1110. In some embodiments, if a certain amount of time from the
start of
the flush cycle elapses (i.e., times out), then the flush cycle 1108 has
successfully
completed and the system moves to the shutdown state 1110. According to
additional
embodiments, if the sensor determines that the piston has not remained in the
down
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position to thereby keep the fluid valve open, the system moves from the flush
state 1108
back to the fill state 1106 to allow more pressurized air to fill the chamber.
Once
sufficient pressure has been added in the fill state 1106 to resume flushing,
as indicated
by the sensor 335, the system may return back to the flush state 1108.
[0074] The shutdown state 1110 may be entered when a flush_stop signal is
received during
the prefill 1104, fill 1106, or flush 1108 states. The shutdown state 1110 may
also be
entered when the flush cycle has completed in the flush state 1108 in response
to a
flush_stop signal or timeout. During the shutdown state 1110, the air
discharge valve is
opened to release pressure from the chamber. Also, the air intake valve is
closed if it has
not already been closed during another state. When the fluid valve and air
valves are
returned to their rest conditions, the system returns to its sleep state 1102
and waits for
the next flush cycle to begin.
[0075] FIGS. 12A-C are timing diagrams of the flushing system according to
various
implementations of the present disclosure. The timing diagrams show the timing
signals
for a controller (e.g., the control circuit 900 or microcontroller 910), a
sensor (e.g.,
proximity sensor 335), an intake solenoid (e.g., the solenoid associated with
gas intake
valve 520), and a discharge solenoid (e.g., the solenoid associated with the
gas discharge
valve 525). These four timing signals are labeled on the left side of the
diagram as
"control," "sensor," "intake," and "discharge," respectively. According to
some
embodiments, the intake solenoid keeps the gas intake valve in a closed
position when at
rest and the discharge solenoid keeps the gas discharge valve in an opened
position when
at rest.
[0076] FIG. 12A shows the timing signals for control, sensor, intake, and
discharge when the
system is operating in a normal manner, according to some embodiments. The
first time
instance may be the initiation of the flush cycle in response to a flush start
signal. The
controller asserts a positive signal to indicate the start. Immediately
thereafter, the
discharge solenoid asserts a positive signal (e.g., positive voltage signal)
to close the
normally-open air discharge valve. The air discharge valve may remain closed
during the
duration of the flush cycle. A predetermined time after this first time
instance, the intake
solenoid asserts a positive signal (e.g., positive voltage signal) to open the
normally-
closed air intake valve, as indicated by the second time instance. The air
intake valve
remains open for enough time until the air pressure sufficiently pressurizes
the chamber.
[0077] The third time instance represents a time (after the air intake valve
has been opened)
when the sensor detects the presence of the piston in the proper position for
flushing. The
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sensor asserts a positive signal and in response the intake solenoid de-
asserts the signal to
close the air intake valve. Since FIG. 12A represents the system operating
normally, the
sensor signal remain high for the remaining duration of the flush cycle,
indicating that the
piston is still in the flushing position. The system remains in this condition
for the
duration of time needed to flush the hydrant (e.g., 30 minutes) or until a
flush_stop signal
is received.
[0078] When the flushing time has expired or the flush_stop signal is
received, the controller
provides a negative signal, which indicates the end of the flush cycle.
Immediately
thereafter, the discharge solenoid is de-asserted, thereby opening the air
discharge valve
and releasing the pressure, causing the piston to return to its stable state
and out of range
of the proximity sensor. The sensor senses this change and outputs a low
signal to
indicate that the flushing cycle has ended. It may be noted that the air
intake valve had
been closed prior to the end of the flush cycle and does not need to be closed
at this time.
[0079] FIG. 12B shows a situation where a certain amount of leakage from the
pressure
chamber may occur. In this case, the air intake valve is opened and then re-
opened in
order to maintain adequate pressure. The first three time instances are the
same as
described above with respect to FIG. 12A. At the fourth time instance shown in
FIG. 12B,
the sensor detects that the piston has moved out of the flushing position
towards its
normal rest state, which indicates that the fluid valve is closing or closed
and the air
pressure inside the chamber is losing pressure. When the sensor de-asserts a
low signal,
the air intake solenoid valve responds by opening the valve again to apply
more pressure.
At the next time instance, the sensor detects the piston in the flush position
again and the
air intake valve can be closed again. At the end of the flush cycle (e.g.,
when flushing
time period has expired or when a flush_stop signal is received), the air
discharge valve is
opened and the sensor again indicates closure of the fluid valve.
[0080] FIG. 12C shows a situation when the air pressure from the air tanks is
not enough to
properly pressurize the chamber in the allotted amount of time (e.g., five
seconds). The
first two time instances in FIG. 12C are the same as the previous two figures.
However, it
should be noted that in this situation the sensor never detects the presence
of the piston
and never asserts a high signal. After timeout, the microcontroller 910
operates the
discharge solenoid to open the air discharge valve as usual and operates the
intake
solenoid to close the air intake valve. The microcontroller 910 will then
proceed to the
sleep state. Receiving the flush_stop signal after the microcontroller 910
enters the sleep
state does not cause a response in the microcontroller 910.
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[0081] Another embodiment of a flushable hydrant 100' is shown in FIG. 13. The
flushable
hydrant 100' includes a pressure regulation assembly 310'. Pressure regulation
assembly
310' may be similar to pressure regulation assembly 310 except that pressure
regulation
assembly 310' also includes a manual bleed valve 1035 mounted between the gas
intake
valve 520 and the gas discharge valve 525. The manual bleed valve 1035 is
connected to
a tee joint 1031, which is also connected to the gas intake valve 520 and the
gas discharge
valve 525, though the location of the manual bleed valve 1035 between the gas
intake
valve 520 and the gas discharge valve 525 should not be considered limiting.
In the
current embodiment, the manual bleed valve 1035 is a manual piston purge
valve, though
other manual bleed valves 1035 may be used in other embodiments. In some
embodiments, the manual piston purge valve may comprise Parker Instrumentation
model
number 4Z-PG4L-SS, though other manual piston purge valves may be used in
various
embodiments.
[0082] It is possible that pressure may be prevented from being vented through
the exhaust
line 535. For example, the gas intake valve 520 and the gas discharge valve
525 may be
stuck in the closed position after the fluid valve is opened. In another
example, an
obstruction may block the exhaust line 535 after the fluid valve is opened and
the gas
discharge valve 525 is thereafter opened to vent the compressed gas to close
the fluid
valve. In another example, the gas intake valve 520 may open due to a
malfunction and
the chamber 199 is unintentionally pressurized. In these situations, as well
as any other
situation where it is intended that pressure be released and it is not
possible or desirable to
vent through the exhaust line 535, the manual bleed valve 1035 may be opened
to release
the pressure. In the current embodiment, the manual piston purge valve may be
opened by
use of a wrench. In other embodiments, the manual bleed valve 1035 may be
operated by
other methods, including remote operation, use of a screw driver, movement of
a purge
needle within the manual bleed valve 1035, or any other method.
[0083] It should be emphasized that the embodiments described herein are
merely possible
examples of implementations, merely set forth for a clear understanding of the
principles
of the present disclosure. Many variations and modifications may be made to
the
described embodiment(s) without departing substantially from the spirit and
principles of
the present disclosure. For example, compressed gas is but one method of
actuation
among many, including hydraulic, electromechanical, and gravitational, among
others.
Further, the scope of the present disclosure is intended to cover any and all
combinations
and sub-combinations of all elements, features, and aspects discussed above.
All such
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modifications and variations are intended to be included herein within the
scope of the
present disclosure, and all possible claims to individual aspects or
combinations of
elements or steps are intended to be supported by the present disclosure.
[0084] One should note that conditional language, such as, among others,
"can," "could,"
"might," or "may," unless specifically stated otherwise, or otherwise
understood within
the context as used, is generally intended to convey that certain embodiments
include,
while alternative embodiments do not include, certain features, elements
and/or steps.
Thus, such conditional language is not generally intended to imply that
features, elements
and/or steps are in any way required for one or more particular embodiments or
that one
or more particular embodiments necessarily include logic for deciding, with or
without
user input or prompting, whether these features, elements and/or steps are
included or are
to be performed in any particular embodiment.
[0085] Various implementations described in the present disclosure may include
additional
systems, methods, features, and advantages, which may not necessarily be
expressly
disclosed herein but will be apparent to one of ordinary skill in the art upon
examination
of the following detailed description and accompanying drawings. It is
intended that all
such systems, methods, features, and advantages be included within the present
disclosure
and protected by the accompanying claims.
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