U.S. patent application number 14/839317 was filed with the patent office on 2015-12-24 for spring-capture assembly for a spring-biased mechanism and pressure relief valve including same.
The applicant listed for this patent is GIRARD EQUIPMENT, INC.. Invention is credited to Michael FERNANDEZ, Tim GIRARD, Chris LYNCH, Joseph PETRARCA.
Application Number | 20150369385 14/839317 |
Document ID | / |
Family ID | 46317531 |
Filed Date | 2015-12-24 |
United States Patent
Application |
20150369385 |
Kind Code |
A1 |
GIRARD; Tim ; et
al. |
December 24, 2015 |
SPRING-CAPTURE ASSEMBLY FOR A SPRING-BIASED MECHANISM AND PRESSURE
RELIEF VALVE INCLUDING SAME
Abstract
A spring capture assembly is provided for securing a compression
spring of a spring-biased mechanism, such as a spring-biased
pressure relief valve, to permit disassembly of the mechanism
without risk of damage or injury associate with rapid resiling of
the spring from a compressed state. The assembly includes a tool, a
housing having an opening for admitting passage of the tool and
capturing the spring at one end, a spring retainer, and a
compression spring mounted within the housing and captured at one
end by said housing and toward an opposite end by the spring
retainer. The tool is adapted for mating with the spring retainer
and the housing to compress the spring therebetween. The spring
capture assembly may be incorporated into a pressure relief valve
for venting pressure and/or vacuum from a pressure vessel. Provided
also is a method for disassembling a spring-biased mechanism
including a spring capture assembly.
Inventors: |
GIRARD; Tim; (Vero Beach,
FL) ; FERNANDEZ; Michael; (Keansburg, NJ) ;
LYNCH; Chris; (Landing, NJ) ; PETRARCA; Joseph;
(Sparta, NJ) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
GIRARD EQUIPMENT, INC. |
Manalapan |
NJ |
US |
|
|
Family ID: |
46317531 |
Appl. No.: |
14/839317 |
Filed: |
August 28, 2015 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
13155846 |
Jun 8, 2011 |
9121523 |
|
|
14839317 |
|
|
|
|
Current U.S.
Class: |
137/315.41 |
Current CPC
Class: |
B25B 27/26 20130101;
F16K 17/0413 20130101; F16K 15/025 20130101; F16K 17/042 20130101;
Y10T 137/6109 20150401; F16K 43/00 20130101; Y10T 29/49815
20150115 |
International
Class: |
F16K 17/04 20060101
F16K017/04; B25B 27/26 20060101 B25B027/26 |
Claims
1. A spring capture assembly for a spring-biased mechanism
comprising: a tool having a shoulder and an elongated member having
a distal end; a housing having an opening for admitting passage of
said tool; a spring retainer mechanically interlockable to said
tool; and a compression spring mounted within said housing and
captured at one end by said housing and at an opposite end by said
spring retainer; whereby rotation of said tool relative to said
spring retainer with said tool mated to said spring retainer and
said shoulder abutting said housing advances said spring retainer
relative to said tool and acts to compress said compression spring
between said spring retainer and said housing.
2. The spring capture assembly of claim 1, wherein said distal end
of said tool comprises threads, and said spring retainer comprises
complementary threads for mechanically interlocking therewith.
3. The spring capture assembly of claim 1, wherein said spring
retainer further comprises a flange positioned to engage a portion
of said compression spring.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a divisional of U.S. application Ser.
No. 13/155,846, filed Jun. 8, 2011, the entire contents of which
being fully incorporated herein by reference.
FIELD OF INVENTION
[0002] The present invention relates generally to a
spring-capturing assembly in a spring-biased mechanism, such as a
valve including a spring-biased poppet, and more particularly to a
pressure relief valve for a pressure vessel for containing a
pressurized fluid, such as an over-the-road tank trailer, that
includes such a spring-capture assembly, which allows for safe and
easy disassembly of the valve in the field for cleaning or other
purposes.
DESCRIPTION OF THE RELATED ART
[0003] As known to those skilled in the art, an over-the-road tank
trailer is a mobile pressure vessel, typically pulled behind a
truck or tractor, for containing a fluid during transportation from
one point to another. Such contained fluids can be pressurized
fluids or unpressurized fluids, however, the un-pressurized fluids
may become pressurized due to heating of the tank by the sun which
in turn heats the fluid contained in the tank causing it to be
pressurized. Also, during an emergency situation, such as upon the
over-the-road tank trailer becoming heated in a fire, the fluid
contained in the tank can become heated and pressurized.
[0004] A common prior art pressure relief vent for an over-the-road
tank trailer includes a housing mounted on the top of the tank
trailer including a valve seat that is normally engaged by a poppet
forced into sealing engagement with the valve seat by a compression
spring mounted in the housing and providing downwardly-acting force
on the poppet. The underside of the poppet is exposed to the
pressurized fluid in the tank and the pressurized fluid in the tank
provides an upwardly acting force on the underside of the poppet.
As is still further known to those skilled in the art, the
compression spring is preloaded such that the downwardly acting
force provided by the spring on the poppet is sufficient to
maintain the poppet in sealing engagement with the valve seat up to
a set pressure in opposition to any upwardly acting force applied
to the underside of the poppet by the pressurized fluid. As is
still further known, the compression spring must be chosen such
that upon the fluid in the over-the-road tank trailer becoming
over-pressurized to the flow pressure the compression spring will
compress sufficiently upwardly to permit the poppet to be lifted up
off of the valve seat by the force created by the over-pressurized
fluid a distance sufficient to provide a space or opening,
typically an annular space or opening, between the valve seat and
the poppet sufficiently large to permit the over-pressurized fluid
to flow therethrough at a desired flow rate.
[0005] As is still further known, compression springs are
characterized by what is known as a spring constant, which reflects
the distance the spring will compress upon the application thereto
of a given force. Accordingly, as is still further known, the
spring constant for the compression spring of a pressure relief
vent is the difference between the flow pressure and the set
pressure in pounds per square inch times the area of the poppet in
square inches, divided by the distance in inches between the valve
seat and the poppet required to provide the above-noted flow rate.
A general characteristic of compression springs, as is known, is
that the higher the spring constant the stiffer the spring.
[0006] As is still further known, applicable regulations require
that the pressure relief vent for an over-the-road tank trailer be
mounted on the tank trailer as close as possible to the top center
of the tank trailer so that the pressure relief vent is exposed to
the vapor space inside the tank trailer, with such vapor space, as
is known, being the space between the fluid contained in the tank
trailer and the top of the tank trailer. As is further known the
height of the pressure relief vent is determined largely by the
height or length of the compression spring.
[0007] Since the pressure relief vent must be mounted on the top
center of the over the road tank trailer, it is desirable that the
height of the pressure relief vent be as small as possible to
permit the over-the-road tank trailer with the pressure relief vent
mounted on top to safely pass under overhead structures such as
bridges and the like with adequate clearance while maintaining the
required flow rate. This means that the length or height of the
compression spring of the pressure relief vent must be as small as
possible and yet the compression spring, as noted above, must be
sufficiently stiff to maintain the poppet in sealing engagement
with the valve seat at the set pressure and which spring must be
sufficiently un-stiff that it will compress sufficiently at the
flow pressure to permit the poppet to be moved away from the valve
seat a distance sufficient to provide the above-noted flow rate.
Obviously, as known to those skilled in the art, these two spring
requirements are in conflict with each other because, generally
speaking and as is further known, the higher or longer the
compression spring the lower the spring constant and the shorter
the spring the higher the spring constant. Accordingly, to obtain a
relatively shorter height valve, stiffer springs are generally
desired.
[0008] A certain prior art valve is disclosed is commonly assigned
U.S. Pat. No. 5,203,372, the entire disclosure of which is hereby
incorporated herein by reference. This valve is adapted to include
a poppet having a predetermined shape for forming an escaping
stream of over-pressurized fluid into a jet stream that provides a
reaction force that acts against the underside of the poppet to
assist the over-pressurized fluid in lifting the poppet off of the
valve seat upon occurrence of over-pressurization. This increased
upward force in turn allows for use of a relatively stiffer, and
shorter, spring, and advantageously provides a valve with a
relatively lower height.
[0009] Because of the relatively high degree stiffness of the
springs in such valves, a mechanical press is typically required to
compress the spring during routine cleaning of the valve, namely
the surfaces of the poppet in communication with the pressurized
fluid, e.g, between hauls of different pressurized fluids. Thus, it
is typically necessary to remove the valve from the tank, climb
down from the truck, and transport the valve to a hydraulic or
other mechanized press (which is heavy ground-mounted equipment).
This is inconvenient and time-consuming. Further, because of the
stiffness of the spring, it would be impractical to provide a valve
that could be disassembled manually, without the use of a
mechanized press, because as soon as the housing would be
disassembled, the stiff spring would rapidly decompress and tend to
turn the decoupled housing parts into projectiles, which could
result in damage to the valve or other equipment, and poses a risk
of serious harm to service technicians. It is noted that a similar
concern exists in spring-biased mechanisms other than valves that
also require use of relatively stiff springs, and where manual
disassembly is desirable.
[0010] What is needed is a safety assembly adaptable to a broad
range of spring-biased mechanisms that would allow for safe
disassembly of the spring-biased mechanism without safety risks
associated with decompression of the spring during disassembly.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] The present invention will now be described by way of
example with reference to the following drawings in which:
[0012] FIG. 1 is a perspective view of a pressure-relief valve in
accordance with an exemplary embodiment of the present
invention;
[0013] FIG. 2 is a cross-sectional view of the pressure relief
valve of FIG. 1, taken along line A-A of FIG. 1;
[0014] FIG. 3 is an exploded view of the pressure relief valve of
FIG. 1;
[0015] FIGS. 4A and 4B are elevational and cross-sectional views of
the valve of FIG. 1, shown mated with a spring compression tool,
and before compression of the spring;
[0016] FIGS. 5A and 5B are elevational and cross-sectional views of
the valve of FIG. 1, shown with a nut advanced against a housing in
position to compress the spring;
[0017] FIGS. 6A and 6B are elevational and cross-sectional views of
the valve of FIG. 1, shown mated with a spring compression tool,
and after compression of the spring, and showing the frame and
spring assembly removed from the tank mount;
[0018] FIGS. 7A and 7B are cross-sectional views of the valve of
FIG. 1 shown mated with an alternative embodiment of a spring
compression tool;
[0019] FIG. 8 is a cross-sectional view of an alternative
embodiment of the valve of FIG. 1, shown with a spring retainer
having an externally-threaded stud, mated with a tool having
complementary internal threads, and a fixed shoulder;
[0020] FIG. 9 is a cross-sectional view of an alternative
embodiment of the valve of FIG. 1, shown with a spring retainer
having an externally-threaded stud, mated with a tool having
complementary internal threads, and a tool supporting a threaded
nut;
[0021] FIG. 10 is an exploded view of a pressure-relief and vacuum
venting valve in accordance with an alternative exemplary
embodiment of the present invention;
[0022] FIGS. 11A and 11B are elevational and cross-sectional views
of the valve of FIG. 10, shown mated with a spring compression
tool, and before compression of the spring;
[0023] FIGS. 12A and 12B are elevational and cross-sectional views
of the valve of FIG. 10, shown with a nut advanced against a
housing in position to compress the spring;
[0024] FIGS. 13A and 13B are elevational and cross-sectional views
of the valve of FIG. 10, shown mated with a spring compression
tool, and after compression of the spring, and showing the frame
and spring assembly removed from the tank mount;
[0025] FIG. 14 is a cross-sectional view of an alternative
embodiment of the valve of FIG. 10, shown with a spring retainer
having an externally-threaded stud, mated with a tool having
complementary internal threads, and a fixed shoulder; and
[0026] FIG. 15 is a cross-sectional view of an alternative
embodiment of the valve of FIG. 10, shown with a spring retainer
having an externally-threaded stud, mated with a tool having
complementary internal threads, and a tool supporting a threaded
nut.
SUMMARY
[0027] The present invention provides a safety assembly in the form
of a spring-capture assembly, a pressure relief valve including a
spring-capture assembly, and a method for disassembling a
spring-biased mechanism, such a pressure relief valve. The spring
capture assembly permits disassembly of the spring-biased
mechanism, e.g., for cleaning or maintenance purposes, without risk
of damage or injury associated with rapid resiling of the spring
from a compressed state. Accordingly, a relatively stiffer spring
may be used without fear of injury, which advantageously allows for
a shorter height in over-the-road tank trailer valves, and permits
manual valve disassembly in the field by a service technician atop
a tank trailer, using no more than common hand tools.
[0028] A spring capture assembly for a spring-biased mechanism
includes a tool having an elongated member and a distal end, and a
housing having an opening for admitting passage of the tool. The
assembly further include a spring retainer configured to
mechanically interlock with the tool, e.g. via complementary
threads. A compression spring is mounted within the housing and
captured at one end by the housing and toward an opposite end by
the spring retainer. The tool may include a fixed shoulder, such
that rotation of the tool relative to the spring retainer, with the
tool mated to the spring retainer and the shoulder abutting the
housing, advances the spring retainer onto the tool and acts to
compress the compression spring between the spring retainer and the
housing. Alternatively, the tool may include a nut supported on
threads instead of a shoulder. In such an embodiment, rotation of
the nut relative to the elongated member, with the tool mated to
the spring retainer and the nut abutting the housing, withdraws the
tool relative to the housing and acts to compress the compression
spring between the spring retainer and the housing.
[0029] Provided also is a pressure relief valve for venting a
pressure vessel containing a pressurized fluid. The valve includes
a mount having a lower portion adapted for mounting to the pressure
vessel, a passageway for venting fluid therethrough, and an upper
portion defining a first mating structure circumscribing the
passageway. The valve further includes a valve seat supported on
the mount about the passageway, and a poppet matable with the valve
seat to occlude the passageway and disrupt a flow of fluid
therethrough. Further still, the valve includes a housing having a
first portion defining a second mating structure complementary to
the first mating structure, and an opening for admitting passage of
a tool, and a spring retainer having a mating structure
mechanically interlockable with the tool, and a flange. The valve
further includes a compression spring mounted within the housing
and captured at one end by the housing and at an opposite end by
the flange of the spring retainer. The compression spring biases
the poppet from an open position spaced from the valve seat toward
a closed position in abutting relationship with the valve seat. The
tool is an elongated member having a distal portion dimensioned to
pass through the opening of the housing. The tool has a distal
portion having a distal end matable with the mating structure of
the spring retainer to compress the compression spring between the
spring retainer and the housing.
[0030] Also provided is a method for disassembling a spring-biased
mechanism having a spring capture assembly for capturing a
compression spring of the mechanism. The method includes manually
grasping an elongated tool having a distal end, inserting the
distal end of the tool through a housing of the spring capture
assembly, mating the distal end of the tool with a spring retainer
of the spring capture assembly, manipulating the tool to draw up
the spring retainer and compress the compression spring between the
spring retainer and the housing; and disassembling the
spring-biased mechanism.
[0031] The spring-capture assembly allows for safe disassembly of a
valve (or other spring-biased mechanism) without the safety risks
associated with decompression of the spring during disassembly.
DETAILED DESCRIPTION
[0032] The present invention provides a safety assembly in the form
of a spring-capture assembly. The spring-capture assembly is
adaptable to a broad range of spring-biased mechanisms, including a
pressure relief valve. The spring-capture assembly allows for safe
disassembly of the valve (or other spring-biased mechanism) without
the safety risks associated with decompression of the spring during
disassembly. As applied to a pressure relief valve, the
spring-capture assembly advantageously permits a multi-piece valve
construction that can be manually disassembled safely for
poppet/valve cleaning purposes in the field, namely, by a service
technician on the top of an over-the-road tank trailer, using
common hand tools, without the need for a mechanized press or other
heavy ground-based equipment.
[0033] Referring now to FIGS. 1-3, an exemplary pressure-relief
valve including an exemplary spring-capture assembly is shown. This
exemplary valve is useful in venting over-pressurized pressure
vessels such as, for example, an over-the-road tank trailer. As
shown in FIG. 1, the valve 100 is of a multi-piece,
readily-disassemblable construction including an upper housing 10
and a lower mount 60.
[0034] The mount 60 may have various forms, and its lower portion
62 may be substantially conventional in nature. By way of example,
the lower portion 62 of the mount 60 may be adapted for sealably
mounting to a pressure vessel, such as an over-the-road tank
trailer, by welding or mechanical fasteners, and defines a
generally centrally-located passageway 64 for venting fluid
therethrough. Of particular note, and in accordance with the
present invention, the mount 60 includes an upper portion 66
defining a first mating structure 68 that generally circumscribes
(or surrounds) the passageway 64. The first mating structure 68 may
have any suitable configuration provided that it is capable of
serving to mate with and readily releasably secure thereto, e.g.
through the use of no more than common hand tools and without a
need for a mechanized press or other ground-based equipment, the
housing 10. As best shown in FIGS. 2 and 3, in this exemplary
embodiment, the first mating structure 68 comprises external
threads 69. By way of example, the first mating structure could
alternatively include internal threads. Though other mating
structures could be used, complementary threads are preferred for
mating the mount and housing 10, because the threads allow for
mating with relatively more or relatively less compression of the
spring, which adjusts the set pressure (at which spring force is
overcome to cause venting).
[0035] A valve seat 80 is supported on upper portion 66 of the
mount 60 in position so as to circumscribe, and not to occlude, the
passageway 64, in position to mate with a poppet. By way of
example, the valve seat 80 may be provided as a suitable
elastomeric O-ring extending around the passageway 64, as shown in
FIGS. 2 and 3.
[0036] The housing 10 has a lower portion 12 defining a second
mating structure 14 complementary to the first mating structure 68
of the mount 60. The second mating structure 14 may have any
suitable form, provided that it provides a secure, but readily
releasable, mounting to the mount 60 that resists axial separation
of the housing 10 and mount 60. In this exemplary embodiment, the
second mating structure comprises internal threads 16 complementary
to the external threads 69 of the mount 60.
[0037] Further, the housing 10 defines an opening 18 for admitting
passage of a tool, for purposes discussed below. The opening 18 is
located generally toward the center ("centrally located") of the
housing, or toward the center of a spring, as discussed below, and
as shown in FIGS. 2 and 3. Further still, the housing 10 is
provided with openings 20 for venting pressurized fluid (such as
air, gas, or vapor, collectively referred to herein as
"fluid").
[0038] In this embodiment, the valve 100 further includes a rain
shield 30, and a hole plug 34 dimensioned to fit snugly yet
removably within the opening 18 of the housing 10 so as to
substantially occlude the opening, and thus thwart entry of
rainwater or other contaminants.
[0039] The valve 100 further includes a movable poppet 40 matable
with the valve seat 80 to occlude the passageway 64 and disrupt a
flow of fluid therethrough. The poppet 40 includes a central
portion 42 for abutting the valve seat and selectively occluding
the passageway 64. Though optional, in this example, the poppet 40
includes a stick-resistant layer on its underside, to avoid bonding
with the valve seat 80. In this example, the poppet includes a
formed body 44 constructed of stainless steel, and the
stick-resistant layer is provided as a unitary body 48 of PTFE
liner machined to conform to the poppet.
[0040] The valve 100 further includes a compression spring 50
mounted within the housing 10. The compression spring 50 is
positioned within the housing such that its first end 52 abuts
and/or is braced against the housing 10, and its second (opposite)
end 54 is braced against the poppet 40. When assembled, the
compression spring 50 is preloaded, such that it exerts downwardly
acting force, indicated by arrow Z in FIG. 2, against the poppet
40, to urge the poppet 40 into sealing engagement with the valve
seat 80 on the mount.
[0041] In accordance with the present invention, the valve 100
further includes a spring retainer 70 configured to be matable with
the tool to compress the spring 50 within the housing 50, so as to
relieve downward force otherwise exerted by the spring 50 on the
poppet 40. In the exemplary embodiment shown, the spring retainer
70 is configured with an opening 72 having internal threads 74 for
mating with the tool. In an alternative embodiment, the spring
retainer may have other structures, such as a post bearing external
threads for mating with the tool, or a hook, loop, latch or other
structure for mating with the tool to permit upward (as shown in
the figures) pulling on the spring retainer 70 to compress the
spring 50. In this exemplary embodiment, the spring retainer
includes a generally radially-extending flange 76 dimensioned to
capture the second end 54 of the spring 50, and the spring retainer
is positioned between the spring and the poppet 40. Alternatively,
the spring retainer 70 could have other structure, grasp the spring
other than at its end, and be positioned to capture the spring at a
point other than between the compression spring and the poppet.
[0042] Thus, the spring 50 is captured between the spring retainer
70 and the housing 10, and in a normal condition, the spring 50
biases the poppet 40 from an open position spaced from the valve
seat 80 (to permit venting of fluid via the passageway 64) toward a
closed position in abutting relationship with the valve seat 80 (to
thwart venting of fluid via the passageway 64).
[0043] It will be understood that the compression spring 50 is
chosen to have a stiffness sufficient to cause the spring 50 to
exert sufficient downwardly-acting force to maintain the poppet 40
in sealing engagement with the valve seat 80 up to a set pressure
of the valve 100.
[0044] In use, the exemplary valve shown in FIGS. 1-3 is operable
to effectively seal a pressure vessel until fluid contained in the
pressure vessel has become over-pressurized sufficiently in excess
of the set pressure of the valve 100 to produce an upwardly-acting
force that acts against the central underside portion of the poppet
40 (upon liner 48) with sufficient force to overcome the
downwardly-acting force applied against the poppet 40 by the
compression spring 50 and thus to lift the poppet 40 up off of the
valve seat 80. Upon the poppet 40 being lifted up off of the valve
seat, the over-pressurized fluid escapes or is vented outwardly
through the openings 20 in the housing 10.
[0045] Further, in accordance with the present invention, the valve
may be easily and safely disassembled, e.g., by a field technician
atop an over-the-road tank trailer using simple, lightweight common
hand tools such as a soft mallet, screwdriver and/or a combination
or other wrench, by virtue of the valve's inclusion of a spring
capture assembly 90 in accordance with the present invention, as is
illustrated with reference to FIGS. 4A-7B. It should be noted,
after the tool is used to capture the spring and relieve spring
biasing on the poppet, the associated spring tension placed by the
spring on the threads of the mount and housing is relieved, and
thus the mount and housing are loosely coupled and may be easily
decoupled by hand. Such disassembly is required periodically for
service and/or cleaning, e.g., between fillings of the pressure
vessel with different fluids.
[0046] Referring now to FIGS. 3-7B, it is illustrated that the
exemplary spring capture assembly 90 includes at least the housing
10, spring 50, spring retainer 70, and a tool 80 configured to mate
and cooperate with the spring retainer 70 to compress the spring 50
within the housing 10.
[0047] The tool 80 is an elongated member having an elongated body
82 having a distal portion 84 dimensioned to pass through the
opening 18 of the housing 10. The distal portion 84 has a distal
end 86 matable with the spring retainer 70. The spring retainer and
tool may include any suitable complementary structure for mating
purposes, provided that the spring retainer and tool are
mechanically interlockable to resist substantial relative motion
away from each other in an axial direction of the tool, as the tool
is used to draw up the spring retainer and compress the spring
between the spring retainer and the housing. Preferably, the tool
80 further includes a handle 89 extending generally transversely to
the elongated body 82, and thus such a tool 80 is generally
L-shaped (FIGS. 4A-6B) or T-shaped (FIGS. 7A-7B).
[0048] In the exemplary embodiment shown in FIGS. 1-7B, the
centrally-located opening 72 of the spring retainer 70 is provided
with internal threads 74. Accordingly, the distal end 86 of the
tool 80 comprises external threads 88 complementary thereto. In the
embodiment shown in FIGS. 4A-6B, the proximal end 90 of the tool 80
also comprises external threads 88 supporting a complimentarily
threaded nut 92.
[0049] In an alternative embodiment, the tool 80 does not include
such external threads on its proximal end, or a nut, but instead
includes a radially-extending shoulder 94 for abutting the housing
that acts as a stop, as shown in FIGS. 7A and 7B. Unlike the nut,
the shoulder 94 is fixed relative to the body 82, such that the
tool 80 can not be advanced any further into the housing 10 after
the shoulder abuts the housing 10.
[0050] In use, the tool 80 is operable is operable to mate with the
spring retainer 70 and draw up the spring retainer 70 to compress
the compression spring 50 between the spring retainer 70 and the
housing 10. By way of example, the embodiment of the tool 80 shown
in FIGS. 4A -6B may be used as follows to disassemble a valve
having a spring capture assembly 90 for capturing a compression
spring biasing a poppet of the valve. First, the hole plug 34 is
removed from the opening 18 of the housing 10, if necessary, to
clear the opening. Then, the elongated tool 80 having a distal end
86 is manually grasped. Next, the method involves inserting the
distal end 86 of the tool 80 through the housing 10 of the spring
capture assembly 90. Next, the method involves mating the distal
end 86 of the tool 80 with the spring retainer 70 of the spring
capture assembly 90, e.g. by threading together the spring retainer
70 and tool 80, as shown in FIGS. 4A and 4B. Further, the method
involves manipulating the tool 80 to draw up the spring retainer 70
and compress the compression spring 60 between the spring retainer
70 and the housing 10.
[0051] Subsequently, the housing 10 may be disengaged from a
pressure vessel, as shown in FIGS. 6A and 6B. By way of example,
this may involve rotating the housing 10 relative to a mount 60 of
the pressure vessel to decouple complementary mating structures on
the mount and on the housing. This may be accomplished using a
crescent or other wrench to loosen the housing from the mount,
and/or by using a soft mallet and screwdriver to tap against lugs
on the housing. It will be noted that because the spring is
securely captured by the spring capture assembly 90, opposed axial
forces on the mating structures of the housing 10 and the mount 60
are relieved, eliminating binding of the mating structures that
would make decoupling difficult. Further, the spring will not
resile rapidly and cause the housing 10 to "pop off" from the mount
60, thus avoiding injury to personnel during disassembly. Further
still, it will be noted that after the housing/spring capture
assembly 90 has been removed from the mount 60, the poppet 40 is
retained loosely on the mount 60, simply resting on the valve seat
(assuming that the tank trailer has already been depressurized), as
shown in FIG. 6B. Accordingly, a technician may simply manually
lift the poppet 40 from the valve seat 80 and clean its underside,
if necessary, and/or replace the valve seat 80, if necessary.
Notably, this can be accomplished using only common hand tools, and
while a technician is atop a tank trailer, without the need for
ground-based presses or other heavy equipment.
[0052] For embodiments in which the spring retainer 70 includes
internal threads 74 and the distal end 86 of the tool 80 includes
external threads, mating the distal end of the tool with the spring
retainer comprises threading the tool 80 through the spring
retainer 70, as shown in FIGS. 4A and 4B.
[0053] In an embodiment in which the tool 80 includes a shoulder 94
for abutting the housing 10, manipulating the tool involves
threading the tool 80 through the spring retainer 70 until the
shoulder 94 abuts the housing 10 (see FIG. 7A), and then continuing
to thread the tool through the housing while the shoulder abuts the
housing (see FIG. 7B). The continued threading causes the spring
retainer to be drawn upwardly on the threads of the tool, and the
compression spring 50 to be compressed as a result, as best shown
in FIG. 7B. Thus, rotation of the tool relative to the spring
retainer with the tool mated to the spring retainer and the
shoulder abutting the housing advances the spring retainer onto the
tool and acts to compress the compression spring between the spring
retainer and the housing.
[0054] In an alternative embodiment in which the tool does not
include a shoulder but instead includes external threads on its
proximal end 89 that support a complimentarily threaded nut (see
FIGS. 4A-6B), manipulating the tool involves threading the tool 80
into the spring retainer 70 (see FIGS. 4A and 4B) and then
advancing the nut 92 on the tool until the nut 92 abuts the housing
10 (see FIG. 5A and 5B) and draws up the spring retainer 70 to
compress the compression spring (see FIGS. 6A and 6B). The
advancing of the nut 92 causes the elongated member 82 to be drawn
upwardly relative to the housing (while the spring retainer remains
in a substantially constant position on the member), and the
compression spring 50 to be compressed as a result. Thus, rotation
of the nut relative to the elongated member with the tool mated to
the spring retainer and the nut abutting the housing withdraws the
tool relative to the housing and acts to compress the compression
spring between the spring retainer and the housing.
[0055] In another alternative embodiment, the spring retainer 70
comprises external threads 71 on a stem 73 integral with the spring
retainer 70, and the distal end of the tool 80 comprises
complementary internal threads 83. In one such embodiment, the tool
80 further comprises a shoulder 94 for abutting the housing
(similar to that shown in FIGS. 7A and 7B), as best shown in FIG.
8. In such an embodiment, manipulating the tool 80 involves
threading the tool 80 onto the stem 73 of the spring retainer 70
while the shoulder abuts the housing 10, as best shown in FIG.
8.
[0056] In yet another alternative embodiment, the spring retainer
70 similarly comprises external threads 71 on a stem 73 integral
with the spring retainer 70, and the distal end of the tool 80
comprises internal threads complementary thereto 83. However, in
this alternative embodiment, a proximal end of the tool comprises
external threads supporting a complimentarily threaded nut 92 for
abutting the housing (similar to that shown in FIGS. 4A and 6B), as
best shown in FIG. 9. In such an embodiment, manipulating the tool
involves threading the tool onto the spring retainer and advancing
the nut on the tool until the nut abuts the housing and draws up
the spring retainer to compress the compression spring.
[0057] After cleaning/service, the poppets may be replaced on the
valve seat 80/mount 60, the housing 10 may be secured to the mount
60 (e.g., by threading them together), and then the tool 80 can be
rotated or otherwise decoupled from the spring retainer 70 to
restore spring-bias to the valve/mechanism, and to return the
valve/mechanism to service. The tool 80 may then be withdrawn from
the housing 10 and the hole plug 34 may be replaced in the
housing's opening 18.
[0058] FIGS. 10-13B show an alternative exemplary embodiment of a
valve in accordance with the present invention. This embodiment is
similar to that shown in FIGS. 1-7B, but is configured as both a
pressure relief and vacuum venting valve. Many of the components
are identical or virtually identical to those shown in FIGS. 1-7B.
However, as best shown in FIGS. 10 and 11B, in this embodiment, the
poppet 40a is modified to define at least one vent opening 110 in
communication with the passageway, and the valve further includes a
second poppet 120 dimensioned to close the vent opening(s) 110 in
the poppet 40a, a stem 122 extending from the second poppet 120 and
passing though a support opening 112 in the first poppet 40a, a
stop 124 mounted on a distal end 126 of the stem 120; and a spring
130 compressed between the first poppet 40a and the stop 124, the
spring biasing the second poppet 120 from an open position spaced
from the first poppet 40a toward a closed position in abutting
relationship with the first poppet 40a. The second poppet may carry
a suitable valve seat 140, such as a suitable elastomeric O-ring,
to facilitate sealing of the second poppet 120 with the first
poppet 40a.
[0059] Accordingly, in the event that the pressure within the
pressure vessel is sufficiently lower than the ambient pressure
outside the pressure vessel, the pressure differential will cause
the second poppet 120 to move (against the bias of spring 130) from
the closed position toward the open position to admit ambient air
to enter the pressure vessel through passageway 64 via the opening
110 in the first poppet 40a. When the pressure differential has
been sufficiently reduced, the spring 130 will urge the second
poppet 120 into the closed position, thereby thwarting the
continued flow of fluid via the passageway 64.
[0060] Referring now to FIGS. 11A-13B, it is illustrated that the
exemplary alternative spring capture assembly 90 includes at least
the housing 10, spring 50, a spring retainer 70, and a tool 80
configured to mate and cooperate with the spring retainer 70 to
compress the spring 60 within the housing 10.
[0061] Optionally, as in the embodiment shown in FIGS. 11A-13B, the
spring retainer 70 is modified relative to that discussed above to
include at least one axially extending leg 78 positioned to abut
the poppet (which optionally is also modified to accommodate the
leg as best shown in FIG. 9B) and space a portion of the spring
retainer from the poppet 40a to permit fluid to pass therethrough
for venting purposes. Further, the spring retainer 70 may include
openings 75 to permit fluid to pass therethrough for venting
purposes, as best shown in FIG. 10.
[0062] The tool 80 may be identical to the tools described above.
Alternatively, either embodiment described above may be modified to
provide that the distal end 84 of the tool's body 82 is centrally
hollow to admit passage of at least a portion of the second
poppet's stem 122, the stop 124, and optionally a portion of the
spring 130, as will be appreciated from FIG. 11B.
[0063] Alternative embodiments are shown in FIGS. 14 and 15. Such
alternative embodiments are similar to those discussed above with
reference to FIGS. 8 and 9 in that the spring retainer 70 comprises
external threads 71 on a stem 73 integral with the spring retainer
70, and the distal end of the tool 80 comprises complementary
internal threads 83. In one such embodiment, the tool 80 further
comprises a shoulder 94 for abutting the housing, as best shown in
FIG. 14, and manipulating the tool 80 involves threading the tool
80 onto the stem 73 of the spring retainer 70 while the shoulder
abuts the housing 10. In yet another alternative embodiment, the
spring retainer 70 similarly comprises external threads 71 on a
stem 73 integral with the spring retainer 70, and the distal end of
the tool 80 comprises internal threads complementary thereto 83.
However, in this alternative embodiment, a proximal end of the tool
comprises external threads supporting a complimentarily threaded
nut 92 for abutting the housing, as shown in FIG. 15. In such an
embodiment, manipulating the tool involves threading the tool onto
the spring retainer and advancing the nut on the tool until the nut
abuts the housing and draws up the spring retainer to compress the
compression spring.
[0064] In use, the tool 80 is operable to mate with the spring
retainer 70 and draw up the spring retainer 70 to compress the
compression spring 50 between the spring retainer 70 and the
housing 10 in a manner similar to those described above. By way of
example, the tool 80 shown in FIGS. 9A-11B may be used as follows
to disassemble the valve by threading the tool 80 into the spring
retainer 70 (see FIG. 9B), tightening the nut 92 down against the
housing 10 (see FIG. 10B), and then continuing to advance the nut
92 on the tool 80 to draw up the spring retainer 70 and compress
the spring 50 to secure the spring between the spring retainer 70
and the housing 10, and relieve downward force on the poppet 40a,
at which point the housing 10 may be safely and easily decoupled
from the mount 60, as best shown in FIG. 11B. This exposes the
poppets for service and/or cleaning, as best shown in FIG. 11B.
[0065] After cleaning/service, the poppets may be replaced on the
valve seat 80/mount 60, the housing 10 may be secured to the mount
60 (e.g., by threading them together), and then the tool 80 can be
rotated or otherwise decoupled from the spring retainer 70 to
restore spring-bias to the valve/mechanism, and to return the
valve/mechanism to service. The tool 80 may then be withdrawn from
the housing 10 and the hole plug 34 may be replaced in the
housing's opening 18.
[0066] While the present invention has been particularly shown and
described with reference to the preferred mode as illustrated in
the drawing, it will be understood by one skilled in the art that
various changes in detail may be effected therein without departing
from the spirit and scope of the invention as defined by the
claims.
* * * * *