U.S. patent application number 10/194717 was filed with the patent office on 2004-01-15 for inline pressure reducing regulator.
Invention is credited to Larsen, Todd W..
Application Number | 20040007269 10/194717 |
Document ID | / |
Family ID | 29780156 |
Filed Date | 2004-01-15 |
United States Patent
Application |
20040007269 |
Kind Code |
A1 |
Larsen, Todd W. |
January 15, 2004 |
Inline pressure reducing regulator
Abstract
The pressure reducing regulator includes a regulator body with a
tubular portion coaxially aligned with the tubular portion of a
bonnet threaded to the regulator body. A piston has a bore
extending therethrough with the tubular portions extended thereinto
in axial spaced relationship, the body tubular portion mounting a
valve seat to abut against a piston internal shoulder when the
piston has axially moved relative to the tubular portions to a
blocking position to block fluid flow through the regulator. The
piston enlarged diametric portion bottom surface is in fluid
communication with the piston bore in both of the piston positions
but not in fluid communication with the body high pressure inlet
when the piston is in its blocking position. A spring resiliently
retains the piston in its open position when no pressurized fluid
is applied to the body inlet.
Inventors: |
Larsen, Todd W.; (Milaca,
MN) |
Correspondence
Address: |
Clayton R. Johnson
3121 Dakota Avenue
Minneapolis
MN
55416
US
|
Family ID: |
29780156 |
Appl. No.: |
10/194717 |
Filed: |
July 12, 2002 |
Current U.S.
Class: |
137/505.25 |
Current CPC
Class: |
G05D 16/106 20130101;
Y10T 137/7808 20150401; Y10T 137/7834 20150401 |
Class at
Publication: |
137/505.25 |
International
Class: |
F16K 031/12; G05D
016/10 |
Claims
What is claimed is:
1. A pressure reducing regulator, comprising a regulator body
having an upper end and an axial bore opening through the body
upper end, the body bore including an axially intermediate bore
portion that is in part defined by a body cylindrical wall and a
bottom wall remote from the upper end, an axially elongated tubular
portion having a bore portion extending axially therethrough,
extending within the intermediate bore portion and opening to the
intermediate bore portion, the body tubular portion having a first
end part remote from the body bottom wall, a bonnet removably
mounted to the regulator body and having a top portion with an
outlet, a bore opening to the body bore and an axially elongated
tubular portion extending within the bonnet bore coaxially with the
body tubular portion in axially spaced relationship thereto, the
bonnet tubular portion having a first end part axially adjacent to
the body tubular portion first end part, a piston axially movably
extended within the intermediate bore portion and in fluid sealing
relationship to the body wall defining the body bore, the piston
being axially movable between a fluid flow open position and a
closed position to block fluid flow and having a first axial bore
portion with the body tubular portion extending therein, and a
second bore portion having the bonnet tubular portion extending
therein and being in fluid communication with the piston first bore
portion, the bonnet tubular portion having a fluid passageway
opening to the outlet and to the piston bore second portion, a
valve seat mounted to the bonnet tubular portion first end part to
block fluid flow from the body tubular portion to the passageway
when the piston is in its closed position and to permit fluid flow
from the piston first tubular portion to the piston second tubular
portion when the piston is in its open position, first spring means
for resiliently urging the piston to move to its open position and
second spring means for resiliently retaining the piston in its
closed position until the fluid pressure at the outlet decreases
below a preselected value.
2. The pressure reducing regulator of claim 1, wherein the
regulator body has a threaded portion, the bonnet has a threaded
portion forming a mating fit with the regulator threaded portion to
removably mount the bonnet to the body, and a key for retaining the
bonnet in selected adjusted threaded positions relative to the
regulator body to permit adjusting the axial spacing of the tubular
portions relative to one another and thereby an adjustment of the
fluid pressure at the outlet.
3. The pressure reducing regulator of claim 1 wherein each of the
bonnet, including its tubular portion, the regulator body,
including its tubular portion, and the piston is made of a single,
unitary piece of material.
4. The pressure reducing regulator of claim 1 wherein the regulator
body bore has an enlarged diametric bore portion opening to the
intermediate bore portion and opening toward the bonnet top portion
axially opposite its opening to the intermediate bore portion, the
piston has an enlarged diameter first portion in the body enlarged
diametric portion and a second piston portion of a smaller diameter
than the first piston portion and extending within the body
intermediate bore portion to provide a first clearance space
therewith, the piston having a bore opening to the passageway and
to the clearance space both when the piston is in its open position
and in its closed position.
5. The pressure reducing regulator of claim 4 wherein the piston
enlarged diametric portion has a top surface, the bonnet tubular
portion has a shoulder abuttable against the piston top surface to
limit the movement of the piston toward the bonnet top portion and
the piston is abuttable against the bottom wall to limit the
movement of the piston away from the bonnet top portion.
6. The pressure reducing regulator of claim 4 wherein the piston
second bore portion is of a larger diameter than the piston first
bore portion and at its juncture with the first bore portion
provides an annular piston shoulder, the valve seat in the piston
closed position being abuttable against the regulator body adjacent
to the juncture of the piston first and second bore portions.
7. The pressure reducing regulator of claim 4 wherein the bonnet
tubular portion includes an axially elongated tube part having one
end joined to the bonnet top portion and an axially opposite end
mounting the bonnet tubular portion first part, the bonnet tubular
portion first part including a valve seat mount that, in
conjunction with the piston shoulder and the body wall defining the
piston second bore portion, forms a second clearance space and has
an aperture opening to the second clearance space and the bonnet
tubular part, the aperture being part of the passageway.
8. The pressure reducing regulator of claim 4 wherein there is
provided fluid seal means in the piston first bore portion that
provides a fluid seal between the body tubular portion and the
piston, second fluid seal means in the piston second bore portion
axially between the bonnet tubular portion first part and the
bonnet top portion for forming a fluid seal between the bonnet
tubular portion and the piston, the body wall defining the enlarged
diametric bore portion, the piston, the bonnet tubular portion and
the bonnet top portion forming an annular cavity and the bonnet has
a vent port opening to said cavity.
9. A pressure reducing regulator, comprising a regulator body
having an upper end, an inlet for pressurized fluid and an axial
bore opening through the upper end, the body bore having an axially
intermediate bore portion, a bonnet removably mounted to the
regulator body and having a top portion with an outlet, a bore
opening to the body bore and an axially elongated tubular portion
extending within the bonnet bore, the bonnet tubular portion having
a first end part axially opposite the top portion, a piston axially
movably extended within the intermediate bore portion and in fluid
sealing relationship to the body wall defining the body bore, the
piston having a top surface facing the bonnet top portion and an
axially opposite bottom surface with the body intermediate bore
portion opening thereto, the piston being axially movable the
bonnet tubular portion between a fluid flow open position and a
fluid flow blocking position and having a first axial bore portion,
and a second bore portion having the bonnet tubular portion
extending therein in both of the piston positions and being in
fluid communication with the piston first bore portion, first
spring means for resiliently urging the piston to move to its open
position, the spring means being in abutting relationship to the
piston top surface and the bonnet top portion, the bonnet tubular
portion having a fluid passageway opening to the outlet and to the
piston bore second portion, a valve seat mounted to the bonnet
tubular portion first end part and being abuttable against the
piston to block fluid flow from the body tubular portion to the
passageway when the piston is in its blocking position and to
permit fluid flow from the piston first bore portion to the piston
second bore portion when the piston is in its open position, and
cooperating means for applying pressurized fluid from the inlet to
the piston bottom surface and to the first tubular portion when the
piston is in its open position and pressurized fluid is being
applied at the inlet and blocking the application of fluid under
pressure to the piston bottom surface and from the first tubular
portion to the second tubular portion when the piston is in its
blocking position, the cooperating means at least in part being
defined by the piston and regulator body.
10. The pressure reducing regulator of claim 9, wherein the body
bore has an enlarged diametric bore opening to the bonnet top
portion and to the body intermediate bore portion, the piston has
an enlarged diametric portion in fluid sealing relationship with
the body wall defining the body enlarged diametric bore portion and
a reduced diameter portion joined to the piston enlarged diametric
portion and extending within the body intermediate bore portion to
provide an annular clearance space therewith which opens to the
piston enlarged diametric portion, the piston bottom surface being
provided at least in part by the piston enlarged diametric
portion.
11. The pressure reducing regulator of claim 10 wherein the
cooperating means includes a piston cross bore that opens to said
clearance space and to piston second bore portion for applying
fluid under pressure to the piston enlarged diametric portion when
the piston is in its open position and fluid under pressure is
applied to the inlet.
12. The pressure reducing regulator of claim 10 wherein the
cooperating means includes second spring means abutting against the
piston for constantly urging the piston toward its blocking
position.
13. The pressure reducing regulator of claim 9 wherein the
cooperating means includes an axially extending regulator body
tubular portion that opens to the inlet, is coaxial with the bonnet
tubular portion and extends within the piston first bore portion in
axially spaced relationship to the bonnet tubular portion and the
valve seat, both in the piston open and blocking positions.
14. The pressure reducing regulator of claim 13 wherein the piston
first bore portion is of a smaller diameter than the piston second
bore portion to form an annular shoulder, the valve seat in the
blocking position abutting against the piston adjacent to the
annular shoulder.
15. The pressure reducing regulator of claim 14 wherein the bonnet
tubular portion includes an axially elongated tubular part having a
first end joined to the bonnet top portion and a second end joined
to the tubular portion first end part, the tubular portion first
end part comprising a valve seat mount having a frustoconical outer
surface with a minor base axially remote from the tubular part, the
bonnet tubular portion first end part in conjunction with the
piston annular shoulder, the valve seat and the piston wall that at
least in part defines the piston second bore portion providing an
annular clearance space when the piston is in its blocking
position, the bonnet tubular part having a bore extending
therethrough to open to the outlet and form a part of said
passageway and the valve seat mount has an aperture in fluid
communication with the bonnet tubular part and said annular
clearance space to form a part of said passageway.
16. The pressure reducing regulator of claim 15, wherein the
cooperating means includes a cross bore opening to the above
mentioned clearance space and to the body intermediate bore portion
and in fluid communication with the piston bottom surface.
17. The pressure reducing regulator of claim 16 wherein the bonnet
bore has an enlarged diametric bore portion opening toward the
bonnet top portion and to the body intermediate bore portion to
provide an upwardly facing annular shoulder, the piston having an
enlarged diametric portion in fluid sealing relationship with the
wall that in part defines the body enlarged diametric portion and a
second portion joined to the piston enlarged diametric portion and
extending within the body intermediate bore portion to provide a
second annular clearance with the body wall providing the body
intermediate bore portion.
18. The pressure reducing regulator of claim 16 wherein the
regulator body, including its tubular portion, is made of a single
integrally joined piece of material, the bonnet, including its
tubular portion, is made of a single integrally joined piece of
material, the piston is made of a single integrally joined piece of
material.
19. The pressure reducing regulator of claim 16 wherein bonnet and
regulator body having cooperating threaded portions to mount the
bonnet to the regulator body, an O-ring is provided to form a fluid
seal between the bonnet and the regulator body axially between the
bonnet top portion and the threaded portions, one of the bonnet and
the regulator body having an annular groove axially intermediate
the O-ring and the threaded portions, a fluid seal is provided
between the piston and the body tubular portion and a fluid seal is
provided between the piston enlarged diametric portion and the
bonnet tubular portion axially intermediate the bonnet tubular
portion first part and the bonnet top portion.
20. The pressure reducing regulator of claim 16 wherein it is
mountable to a container of fluid under high pressure and the
regulator body includes a valve bore, a neck portion threadedly
mountable to the container and having an inlet, and a second
passageway opening to the valve bore for fluidly connecting the
neck portion inlet to the body tubular portion and a valve member
mounted to the regulator body and extending within the valve bore
to selectively permit fluid flow from the neck portion inlet to the
body tubular portion and block fluid flow from the neck portion
inlet to the body tubular portion.
Description
BACKGROUND OF THE INVENTION
[0001] This invention is for a pressure regulator that is mountable
in a line between a source of pressurized fluid and an object to
which a fluid under a lower controlled pressure is to be
applied.
[0002] In Gold, U.S. Pat. No. 4,667,695, there is disclosed an
annular piston axially movable in a bore in a body (second piston).
The annular piston is resiliently urged to a position to permit
fluid flow therethrough from its inlet end to its opposite end and
thence through holes in the body. With an increase of pressure at
the inlet end of the annular piston, the annular piston is moved
toward its closed position.
[0003] Lachmann et al, U.S. Pat. No. 4,475,888, has a valve body
with lower passages converging to open to a central bore while
Miller, U.S. Pat. No. 5,501,247, discloses using a ke to prevent
relative rotation between two parts of a pressure regulator.
[0004] In order to make improvements in inline pressure reducing
regulators, this invention has been made.
SUMMARY OF THE INVENTION
[0005] The inline pressure reducing regulator includes a regulator
body having an inlet that opens through a tubular portion (sleeve)
that extends within a piston chamber to a piston bore portion and a
bonnet having an outlet that opens through a bonnet tubular portion
(sleeve) and apertures opposite the outlet to the piston bore. The
piston has the body tubular portion extending into one end portion
of the piston bore and the bonnet tubular portion extending into
the other end of the piston bore. A valve seat is mounted by the
apertured end of the bonnet sleeve to abut against an annular
shoulder in the bore of the piston to block fluid flow
therethrough. A first spring abuts against the body to urge the
piston to a regulator closed position while a second spring abuts
against the bonnet to urge the piston to a regulator open position.
A key acts between the bonnet and regulator body to retain them in
limited adjusted axial positions to permit a limited adjustment of
the outlet pressure.
[0006] One of the objects of this invention is to provide a
pressure reducing regulator having new and novel means for reducing
the leakage paths between the regulator inlet and outlet. Another
object of this invention to provide in a pressure regulator new and
novel means for blocking fluid flow therethrough and if there is
seat leakage, the extra outlet pressure increases the seat load to
block fluid flow and form a new seat area to eliminate future
leakage. An additional object of this invention is to provide in an
inline pressure regulator, new and novel seat means for eliminating
decaying inlet effects without the sacrifice of fluid flow
shutoff.
[0007] Still another object of this invention is to provide new and
novel means in an inline pressure regulator to minimize the
possible leakage paths between the regulator inlet and the
regulator outlet. A different object of this invention is to
provide new and novel means in a pressure regulator for making
small adjustments in the regulator outlet pressure.
[0008] Even though for convenience terms such as "upper", "lower",
"top" and "bottom" will be used in describing the pressure
regulator, it is to be understood the usage of these terms is
applicable to when the pressure regulator is in an upright position
such as illustrated. However, it is to be further understood that
the pressure regulator may be used in other than an upright
position.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 is a cross sectional view of the first embodiment of
the pressure regulator apparatus of this invention in its piston
closed position for blocking fluid flow therethrough;
[0010] FIG. 2 is an enlarged fragmentary view of a portion of the
structure of FIG. 1;
[0011] FIG. 3 is a still further enlarged view of the valve seat
area of the regulator; and
[0012] FIG. 4 is a cross sectional view of the second embodiment of
the invention.
DESCRIPTION OF THE PREFEERED EMBODIMENTS
[0013] Referring to FIG. 1 of the drawings, the inline pressure
regulator apparatus of the first embodiment of the invention,
generally designated 11, includes a regulator body, generally
designated 10, with a bore B of varying diameters extending axially
therethrough. A bonnet (cap), generally designated 12, is
threadedly mounted to the upper portion of the body to close the
upper end of the body bore. The bonnet has a bore D extending
axially therethrough, other than for a valve seat 16 and the valve
seat mount 24A, and is coaxial with the body bore.
[0014] The body bore B includes an axially intermediate bore
portion 14 that is in part defined by an annular bottom wall 15
with an axially elongated sleeve (tubular portion) 17 integrally
joined to the body lower part and extending axially a smaller
distance above the bottom wall 15 than the axial dimension of the
bore portion 14. The sleeve has a bore portion 18 extending axially
therethrough and opens to the body pressurized body inlet 19 in the
body part 17A, the bore portion 18 and inlet being parts of the
body bore B. Thus, the sleeve opens to the intermediate bore
portion axially intermediate its axially opposite ends. The bore
portion 18 is of a much smaller diameter than that of each of the
body intermediate bore portion and the inlet.
[0015] The body bore B also includes an enlarged diameter bore
portion 20 that at its juncture with the axially intermediate bore
portion forms an annular shoulder 21 and opens through the top
annular edge of the regulator body to the annular top part 22 of
the bonnet 12. The bore portion 20 is of a constant diameter for at
least substantially the entire distance above the shoulder 21.
[0016] The bonnet has an annular portion 23 extending downwardly
from the top part 22, the lower part of the annular portion being
threadedly mounted to the regulator body. The bonnet also has an
axially elongated tubular portion (sleeve) 24 integrally joined to
and extending downwardly from the top part in coaxial relationship
to the body sleeve, and advantageously is of a greater axial length
than the bonnet annular portion 23. Thus the bonnet top part 27 has
a wall that in part defines an annular chamber opening to the body
enlarged bore portion and has the upper annular part 29 of the
regulator body extended thereinto.
[0017] The bonnet tubular portion has a top part 24B that is of a
given outer diameter for the major part of its length from the
bonnet top part and has a reduced outer diameter part 24C to, at
its juncture to the top part 24B, forms a downwardly facing
shoulder 25. The reduced diameter part 24C at its lower end has the
valve seat mount 24A formed integrally therewith. The seat mount at
its upper end is of the same outer diameter as that of the tubular
part 24C with the major base of a lower frustoconical portion 24E
joined thereto. The frustoconical portion has its minor base joined
to a cylindrical portion 24D. The reduced diameter part of the
valve seat is extended into a socket in the cylindrical portion,
the lower part of the seat being of a frustoconical shape for
purpose that will be referred to hereinafter. The valve seat may be
press fitted or otherwise suitably adhered to the seat mount
without there being any threaded connection. The valve seat, in
constantly being subjected to the high fluid pressure in the piston
bore portion 38, acts to more firmly retain the valve seat mounted
to the bonnet seat mount. As a result of the valve seat being
mounted without the use of threads, there is a decreased chance of
particle generation during assembly which could result in leakage
flow bypassing the valve seat.
[0018] Mounted in the body bore portions 14, 20 for axial movement
is annular piston (sensor) P, the piston having an enlarged
diameter portion 30 to form a close sliding fit with the body wall
portion that defines the cylindrical part of bore portion 20. The
enlarged diametric portion has an annular groove with an O-ring 31
to form a fluid seal with the bore portion wall during the entire
axial movement of the piston relative to the bonnet tubular
portion. Further, the piston has an axial intermediate portion 32
joined to the enlarged diameter portion to extend downwardly
thereof in bore portion 14 and is of a significantly smaller
diameter than bore portion 14. The piston also includes a reduced
diameter portion 33 joined to the intermediate portion 32 to extend
downwardly thereof to provide a shoulder against which a coil
spring 35 abuts. The opposite end of the spring abuts against the
bottom wall 15 to constantly resiliently urge the piston axially
away from the bottom wall 15. The movement of the piston in the
opposite axial direction is limited by the piston enlarged
diametric portion 30 abutting against the shoulder 21.
[0019] The piston has a top bore portion 37 opening through the top
surface thereof and has the bonnet tubular portion 24C extended
thereinto. The piston enlarged diametric portion has an internal
groove with an O-ring 41 therein to provide a fluid seal with the
tubular portion 24C as the piston moves axially relative to the
tubular portion 24C. The axial movement of the piston axially away
from the bottom wall 25 is limited by abutting against the shoulder
25.
[0020] The piston bore includes a lower bore portion 38 of a
smaller diameter than that of bore portion 37 to provide an annular
upwardly facing shoulder 39, the diameter of bore portion 38 being
greater than the minimum diameter of the minor base of the
frustoconical part 16A of the valve seat, but less than the maximum
diameter of the major base of the frustoconical part 16A. The wall
of the piston that defines bore portion 38 is of a diameter to form
a close axial sliding fit with the body tubular portion 17, the
piston reduced diameter portion 38 having an internal groove in
which an O-ring 40 is mounted to form an axial fluid sealing fit
with the tubular portion 17 during the entire axial movement of the
piston relative to the tubular portion.
[0021] The frustoconical part 24E has a plurality of apertures 43
that converge upwardly to open to the bore 44 of the bonnet tubular
portions 24B, 24C which in turn opens to regulator outlet (passage)
45 in the bonnet top portion 22. The apertures open to the annular
clearance space 49 that is, at least in a substantial part, bounded
by shoulder 39, the wall of the piston that defines the lower part
of the tubular bore portion 37, the seat mount and the valve seat
when the piston is in its closed (fluid flow blocking) position.
When the piston is in its closed position, it has an axial
intermediate part of the seat frustoconical portion 16A abutting
against the piston at the juncture of the piston bore portions 37,
38 to block fluid flow from tubular portion bore 17 to the piston
bore portion 37. Radial cross bores 48 are provided in the piston
axial intermediate portion 32 to open to the clearance space 49 and
to the annular clearance space 47 between the piston wall defining
bore portion 14 and the part of the piston that extends below the
piston enlarged diametric portion. The transverse area of the
clearance space 47 is greater than that of the piston shoulder 39
such that even if the part of the bottom surface of the piston
enlarged diametric portion were to abut against shoulder 21 and the
part of the bottom surface piston of the piston reduced diameter
portion were to abut against the body bottom wall 15, the part of
the piston bottom surface subjected to pressurized fluid is
sufficiently great to move the piston toward its closed position
against the action of a coil spring 50 when the fluid pressure in
the annular space 47 is at or above the preselected outlet
pressure.
[0022] The coil spring 35 constantly resiliently urges the piston
to a position that the part of the piston surrounding the opening
of bore portion 38 to bore portion 37 abuts against the
frustoconical part of valve seat to block high pressure fluid flow
through the piston bore. The coil spring 50 is in the bore portion
20 and acts between the bonnet top portion 27 and the top surface
of the piston to resiliently urge the piston to move relative to
the bonnet tubular portion 24 to a regulator open position to
permit high pressure fluid flow through the regulator. The spring
50 will retain the piston in an open position to place the bonnet
tubular portion in fluid communication with the cross bores 50 and
thereby with the annular clearance space 47 when no fluid under
pressure is applied at the body inlet 19.
[0023] A stop screw 54 is threaded into the bonnet and extended
into a regulator body annular groove 55 that is of a sufficient
axial dimension to permit unthreading of the screw and then
rotating the bonnet relative to the regulator body and thence
threading the screw to abut against the regulator body for
retaining the bonnet relative to the regulator body in an adjusted
threaded (angular) position. Since such a threading adjustment
varies the axial distance between the bonnet top portion 27 and the
body shoulder 21, this provides small outlet pressure adjustments
without the use of shims that are commonly used in conventional
inline regulators. The annular groove is provided above the
threaded connection between the regulator body upper portion 29 and
the bonnet portion 23 while an O-ring 56 provides a fluid seal
between the body portion 29 and bonnet portion 23 above the annular
groove.
[0024] The bonnet has a vent port 52 that opens to the cavity
(chamber) 34 between the tubular portion 24 and the body portion 29
axially between the top portion 27 and the piston. The leakage
fluid in the above mentioned chamber can flow through the port 52
to a suitable container 53 for leakage gas or otherwise plumbed to
a safe area. With the above bonnet-piston-regulator-O-ring
arrangement, any and all leakage flow bypassing the O-rings flows
through the port 52. Further, with this arrangement, the number of
possible leakage paths between the inlet and outlet are
reduced.
[0025] The outlet pressure can be adjusted by using springs 35 and
50 having the desired spring characteristics and the appropriate
threaded adjustment of the bonnet relative to the regulator body.
Due to the fluid connection of the outlet through the bonnet
tubular portion bore 44, apertures 43, annular space 49 and cross
bores 48, the outlet pressure acts against the downwardly facing,
annular piston shoulders 57, 58, 59 which are of much greater cross
sectional area than the corresponding maximum transverse cross
sectional area of the valve seat. When the outlet pressure
decreases below a preselected valve, the spring 50 moves the piston
downwardly and thereby the juncture of the piston bore portions 37,
38 axially away from the valve seat. As a result, high pressure
fluid flows from the inlet 19, through bore portion 38 to pass
through the annular clearance space 49 between the valve seat and
the piston bore to the apertures 43 and thence to the tubular
portion bore 44 to flow to the bonnet outlet 45. At the same time
the annular space 49 is in fluid communication with the space 47
and thereby with the piston shoulders 57-59. As the fluid pressure
at the outlet 45 increases, the pressure acting against the piston
bottom surface increases and the spring 50 is increasingly
compressed, the piston moves toward a valve closed position and,
upon the fluid pressure at the outlet increasing to the preselected
level, blocks fluid flow from the inlet to the annular space
49.
[0026] To be noted that as the inlet pressure decreases (for
example as a result of the emptying of the gas in a gas supply
tank), when the piston is it open position, the pressure on the
bottom surfaces decreases and the spring 50 moves the piston in a
further opening direction. As a result, as the inlet pressure
decreases there is an outlet increase to eliminate the decaying
inlet effect. Even though not mentioned, it is to be understood
that the movement of the piston to its open position may be of
varying axial spacing of the regulator sleeves from one another as
a result of the rate of fluid flow required to maintain the desired
outlet pressure. Thus, in the piston open position, the valve may
just be slightly spaced from the juncture of the piston bore
portions 37, 38 to permit a low rate of flow through the regulator
to a maximum spacing to permit a higher rate of flow through the
regulator.
[0027] In the event there is leakage flow past the valve seat,
there is leakage fluid flow into the annular space 49 and thence
through the cross bores to act against the piston bottom surfaces.
Due to the transverse annular area of the piston surface 39 being
many times smaller than the combined transverse area of the piston
surfaces 57-59 and the valve seat being made of a material, for
example plastic, that is more easily deformable than that of the
piston, the increasing leakage pressure acting against the piston
forces the valve seat to deform sufficiently that there is a new
seating of the piston against the valve seat to block bypass
leakage flow. This seating action provides an increased resistance
to seat leakage caused by vibration. The valve seat is made of a
material that if deforms only the amount necessary to form a new
seating (annular point of contact of the valve seat with the
piston) to block the leakage flow. After the piston moves to its
open position subsequent to the new seating, the piston in again
moving to its closed position, resumes its new seating.
[0028] Advantageously, each of the bonnet, including its tubular
portion, and the regulator body, including its tubular portion, and
the piston is made of a single, unitary piece of material with each
the members having its parts integrally joined to one another. As a
result, the number of O-rings and the chance of leakage are
reduced. Further, the bores of the piston, regulator body, bonnet,
other than for the cross bores and apertures 43, of the first
embodiment are coaxial.
[0029] Referring to FIG. 4, the second embodiment of the invention
includes a bonnet (cap) 12, a piston P and a coil spring 50 that
are the same as those of the first embodiment and function in the
same manner. The second embodiment also includes a regulator body,
generally designated 70, having a bore 73 that is in part defined
by a bottom wall 72, and a sleeve 71 that are the same as the same
parts of the first embodiment. However, the regulator body of the
second embodiment differs from that of the first embodiment in that
it incorporates a valve bore 79 for having a shutoff valve,
generally designated 80, threaded therein. A passage (bore portion)
78 extends axially through the sleeve 17 and opens to the bore 79.
An inlet passage 77 opens to the bore 79 and through the externally
threaded neck portion 81, the threaded portion being threadedly
mountable to the discharge neck portion of a convention gas tank
82.
[0030] The shutoff valve 80 includes a valve body 84 threadedly
mounted to the regulator body bore 79 and a valve stem 85 rotatably
mounted by the valve body for selectively permitting fluid flow
through the valve seat 87 from the passage 77 to the passage 78,
the valve seat being mounted in the regulator body bore. There are
provided O-rings 88 for forming a fluid seal between the regulator
body and the valve body and a fluid seal between the valve stem 89
and the valve body. By incorporating the shutoff valve in the
regulator body, no external plumbing is required for connecting the
pressure regulator to a high pressure gas tank 82. Thus, the
shutoff valve can be used for controlling the flow of high pressure
fluid from the high pressure source (gas tank) to the regulator
body tubular portion 71.
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