CA1233392A - Pressure regulator with friction dampener - Google Patents

Abstract

Abstract OF THE INVENTION
An improvement in a pressure regulator including a valve body, co-engaging seat and poppet, adjustable spring having a bottom plate for co-acting with a low pressure diaphragm member characterized by; for example, a relatively movable seat that includes a centering extension shaft extending to the low pressure side of the valve seat and movable into contact with a ring poppet including a centering and dampening upper protrusion that frictionally encompasses and engages the centering extension shaft of the movable seat to frictionally damp out oscillations of the movable seat and prevent destructive vibrations when gas flow is called for by the regulator. It matters little whether the seat or the poppet is movable and has the delineated centering and dampening structure. Preferably a second spring supports the movable structure.

Description

Docket Jo. DF-476 PRESSURE REGULATOR WIT FRICTION DAMPENER
SPECIFICATION

F id Of The Invention This invention relates to pressure regulators.
More particularly, it relates to pressure regulators such as are employed on manifolds or on cylinders of 5 compressed gases like oxygen in which a wettable lower pressure is controlled by an adjustable spring mechanism and in which the gas is throttled to the low pressure from a high pressure.
Description Of The Prior Art The prior art has seen the development of a wide variety of pressure regulators for reducing discharge pressure from manifolds or high pressure cylinders of compressed gases such as oxygen to a low pressure of only a few pounds per square inch (psi) as in hospital 15 oxygen systems, torches and the like. Basically these regulators have consisted of a cartridge, including either a movable poppet or seat and opposing seat or poppet to control flow as necessary to attempt to effect balanced forces between a heavy spring opposed 20 by a diaphragm to which low pressure is applied.
Patents such as US. 3,586,037 showed the ways of compensating single stage pressure regulators to obtain accurate regulation regardless of what the inlet pressure was. Later filed patents such as 3,812,877 end its 25 divisional 3,906,982, described apparatus for overcoming the significant friction that accompanied long expanses of metal-to-metal contact in many of the prior art regulators. Still later ones such as US. ~,257,450 show pressure regulators having a lost motion connection 30 so as to obtain reliable complete valve closure at every shutoff regardless of whether or not there were particles of I

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carbon or the like adjacent the seat of the regulator.
One of the problems that has persisted in this field of pressure regulators and has not been satisfactorily solved is that of oscillation induced through resonance, or vibration, caused by the high pressure gas flowing past a valve seat or poppet as it nears its matins poppet or seat. This vibration is very destructive to the respective seat or poppet, particularly where one its hard metal or the like. Moreover, it produces a noisy vibration called "singing". In United States Patent No. I, 471,802, by a co-worker David A. Prior, entitled "PRESSURE REGULATOR ASSEMBLY WITH
IMPROVED CARTRIDGE", assigned to the assignee of this invention, there was described an improvement employing a movable poppet with a smaller diameter upper shaft extension and a larger diameter lower shaft extension cooperating with a biasing means to eliminate destructive and noisy vibrations referred to as "singing" when gas flow was needed. While that invention was very helpful in alleviating some of the problems, it was not totally satisfactory. It would be desirable to provide a relatively soft seat to move into contact with a hard ring poppet to be able to obtain larger variations in volumetric rates of flow yet still affect positive sealing and shut-off of the fluid.

Summary Of The Invention Accordingly, it is an object of this invention to provide a pressure regulator assembly having an improved cartridge that eliminates the destructive and noisy vibration between poppet and seat when throttling gas flow; yet, that can handle large variations in the volumetric rate of flow of the gas and still achieve a positive shut-off when needed.
Specifically, it is an object of this invention to provide high pressure regulator for reducing gas pressure from a high pressure manifold or cylinder of the gas to a low pressure end-use in which the poppet and seat are moved apart to be opened when additional gas flow is required as sensed by a regulator spring opposing a diaphragm subjected 5 to the low pressure and in which the poppet and seat can be moved together to give a positive seal and closure when pressure is adequate and in which the improved cartridge of the regulator eliminates destructive and noisy vibration referred to as "singing" when gas flow is needed.
These and other objects will become apparent from the descriptive matter hereinafter, particularly when taken in conjunction with the appended drawings.
In accordance with this invention, there is provided an improvement in a pressure regulator for reducing pressure 15 from high pressure to a low pressure in which the regulator includes a valve body, seat and poppet, adjustable spring and diaphragm member in the usual type regulator construction.
The improvement is characterized by having an improved cartridge in which there is included a nozzle, a movable 20 seat including a centering extension shaft means extending to the low pressure side of the plane of contact between the movable seat and a ring poppet, the centering extension shaft extending upwardly through an orifice in the superstructure 25 of the nozzle and the valve seat assembly being longitudinally movable within a skirt defining a lower chamber in communication with the inlet and high pressure chamber for moving the valve seat in the form of a thermoplastic ring toward a ring poppet in the form of a metallic ring defined by the nozzle.
30 The nozzle has fluid passageways extending radially and angularly outwardly from a central passageway disposed armularly about the centering extension shaft. The centering extension shaft has a centering and dampening upper protrusion that encompasses it and has a plurality of slots defining a plurality of fingers for frictionally dampening oscillations of the centering extension shaft. A
spring holds the seat assembly reciprocally movable within the skirt of the nozzle. The centering and dampening upper 5 protrusion closely encompasses the centering extension shaft and has its fingers defined with at least two slots disposed substantially uniformly thereabout such that the centering extension shaft is dampened and guided to obtain oscillation-free flow. In a preferred embodiment there are 10 the two slots disposed diametrically opposite each other or balance loading on the poppet although four, six, or more can be employed and still operate.

Brief Description Of The Drawings Fig. 1 is a partial cross-sectional view of the pressure regulator in accordance with one embodiment of this invention.
Fig. 2 is a partial cross-sectional view of the improved cartridge in accordance with another embodiment of this invention.
Fig. 3 is a top plan view of the nozzle ox the embodiment of Fig. 1.
Fig. 4 is a side elevation Al view of the nozzle of Fig.
3.
Fig. S is a cross-sectional view taken along the lines 5-5 of Fig. 3.
Fig. 6 is a top plan view of the centering and dampening upper protrusion of Fig. 1.
Fig. 7 is a cross-sectional view taken along the lines 7-7 of jig. 6.
Fig. 8 is a partial cross sectional view of the improved cartridge assembly of one embodiment of this invention emplaced in a bottom portion of a valve body of a line, or L-type, regulator.

Fig. 9 is a partial cross-sectional view of the improved cartridge assembly in a stationary, rear entry, or S-type, regulator in accordance with another embodiment of this invention.
Fig. 10 is a cross sectional view of one embodiment of the seat assembly, including the centering extension shaft and seat.
Fig. 11 is a plan view of the seat retaining ring of lug. 10.
IT Fig. 12 is a side elevation Al, partly in section, of the seat retaining ring of Fig. 11.

Description Of Preferred Embodiment(s) In a low pressure regulator, such as employed in this invention, the downstream pressure is usually regulated to only a few psi and usually the upstream pressure will not exceed about 350 psi maximum. With proper design, however, it can be used on cylinders of pressure up to 2,000-3,000 psi but high pressure bodies are required for this type of regulation. It is noteworthy that this regulation can also be employed on vacuum regulation.
In Fig. 1 there is illustrated a cross-sectional view of a regulator 11 in accordance with one embodiment of this invention. The regulator 11 comprises the main sub-assemblies of body 13, housing cap lo with its adjustable spring 17, diaphragm means 19 and cartridge, or core assembly, 21.
The body 13 has inlet passageway 23, inlet chamber 25, olltlet passageway 27 and outlet chamber 29. As striated, the inlet and outlet passageways 23, 27 are threaded so as to receive a properly threaded male insert, such as a nipple, threaded insert, or the like.
Swiss recognized, such threads may be appropriately right handed or left handed depending upon the nature of the gas and to prevent inadvertently attaching the so I

regulator 11 to an incorrect cylinder of gas. For example, regulators that are employed on inert gases may have substances, such as oil or grease, that would be incompatible with reactive gases, such as oxygen.
Coded threading is frequently employed to prevent inadvertent wrongful attachment and is employed as appropriate in the body of this regulator 13.
Inlet passageway 23 and the inlet chamber 25 may be subjected to the high pressure before it is regulated to the lower pressure and are designed to handle the high pressure. Conversely, the outlet passageway 27 and the outlet chamber 29, ordinarily, are subjected to only the lower, regulated pressure to which the regulator is set by the adjustment setting given by way of the regulator cap 15 and its adjustable spring 17.
The regulator cap 15 is removably affixed to the body 13, as by threaded connections, and has a compression adjusting means illustrated by threaded stud 3] screwed through tapped bushing 33 which is, in turn, fitted into a receiving well in the cap 15, as by press fitting or the like. It is noteworthy, however, that it is unnecessary to have a press fitting, since the bushing 33 is held in place by the upward reaction to the downward pressure of the threaded stud 31 engaging the spring button 34 pushing downwardly on the spring 17 The adjustable spring 17 has a bottom plate 35 contiguous the diaphragm means 17 and is adapted to move therewith as pressure changes in the outlet chamber 29. The spring 17 co-engages the button 34 at its top and is responsive to the bottom of the threaded stud 31. A handle 41 is provided for screwing the threaded stud 31 to obtain a desired low pressure being regulated. Specifically, rotation of the handle causes rotation of the stud to increase or decrease the low pressure that is regulated downstream of the regulator 11 .

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Adjustable spring 17 is made of any material that will have the required strength. For example, it may be made of steel, since it is not subjected to corrosive gases. The usual type springs may be employed in this regulator and no 5 special alloys or springs are required.
The diaphragm lo is held in place intermediate the top 15 and the body 13. It engages the valve stem of the cartridge 21 and is contiguous to and moves concurrently with the bottom plate 35. Ordinarily, the diaphragm will be 10 formed of a tough flexible material such as Neoprene or other fluid impermeable material. The polyflourinated hydrocarbons can be employed in accordance with conventional technology in such instances. The diaphragms employed in the prior art with the respective gases may be employed in 15 this invention and no special material or construction is required.
The main improvement of this invention lies in the improved cartridge 21 and its included movable seat 43 and ring poppet 45, also as shown in Fig. 2. Specifically as 20 illustrated, the cartridge 21 includes a reciprocally movable seat assembly 47 and a nozzle 49.
The seat assembly 47 is illustrated in more detail in Fig. 10. It contains the seat 43 held in place by a seat holder 51 interiorly of a retaining nut 53 and disposed 25 peripherally about a stem, or centering extension shaft, 55. As illustrated, the stem 55 is threadedly received in a threaded aperture inside the seat holder 51 and protrudes upwardly for engaging the diaphragm means 19 for being moved responsive to changes in pressure. Since the downward 30 depression of the stem 55 causes downward depression of the seat assembly 47, gas flows in turbulent flow about the seat assembly 47 ~33~

and intermediate the seal 43 and the ring poppet 45.
As a consequence of this turbulent flow, the seat assembly would tend to oscillate badly in the absence of some restraining means. In fact, the oscillation is so bad with a "singing" regulator thaw the regulators can sometimes self-destruct. Consequently, there is provided a centering and dampening means 57 about the stem 55 near its upper end. The centering and dampening upper protrusion means 57, Figs. 6 and 7, is provided for centering and dampening the stem 55 The centering and dampening means 57 comprises a body 59 that encompasses the shaft 55 and has a plurality of fingers 61 that extend in the illustrated embodiment from the body toward the low pressure chamber 29 for frictionally engaging the shaft 55. The fingers 61 are formed by a plurality of slots 63 cut into the centering and dampening means 57. There are as many slots as there are fingers and the slots are preferably disposed substantially uniformly about the centering and dampening means. For example, only two slots may be formed, for example, diametrically across the centering and dampening means 57, as illustrated in Figs. 6 and 7. On the other hand, four slots may be formed by completely across at 90 with respect to each other. More slots can be formed if desired but they are not necessary and represent a waste of assembly time and money.
It is easier to mold the structure of the centering and dampening means with one or two complete slots forming respectively, two or four fingers. Consequently, I these embodiments are preferred.
This type of structure is also advantageous in that the respective fingers with the 'fears" on top allow it to be snapped in place in the aperture in the nozzle, and the fingers serve as a guide in combination with the lower retaining nut holding the seat in the seat assembly.

9_ If there is too great a friction or if the amount of switches on the fingers is too great, the drag increases pressure drop in the operation of the regulator. If, on the other hand, there is too little drag, the fingers fail to eliminate chatter, or oscillation of the movement between the respective poppet and seat assembly portions.
In addition to the body and fingers illustrated in jigs, 6 and 7, the centering and dampening means 57 also includes an O-ring 65 that is slipped over the fingers and 10 is positioned intermediate the body 59 and the nozzle 49.
Specifically, as illustrated more clearly in Fig. 2, the centering extension shaft 55 extends upwardly through an aperture defined by the walls 69 of the superstructure of the nozzle 49. The centering and dampening means can be 15 snapped into place in the aperture when the stem 55 is not in place. Once the stem 55 is in place, however, the centering and dampening means 57 is not extruded through the aperture 69. The O-ring 59 has the desired effect of causing clamping of the fingers 61 against the shaft 55 so 20 as to frictionally engage and dampen oscillations of the valve seat assembly 49 by restricting and dampening out longitudinal and lateral oscillations of the shaft 55.
The nozzle 49 is threadedly received in the body 13.
It has a chamber 71 defined by the interior of its skirt 73 25 for slide ably receiving the seat assembly 47. It contains a central passageway 75 disposed annularly about the shaft, or stem 55 and has a plurality of radially and angularly outwardly extending passageways 77 for gas flow, such that it is not necessary that the gas flow be through the centering and dampening means 57.
The reciprocally movable seat 47 is held upwardly interiorly of the chamber 71 by spring 79. The sea assembly 47 has splints 81, Figs. 2 and if, such as on the exterior of the retaining nut 53, to fissility flow of fluid therapist. As can be seen in Fig. 12, the retaining nut 53 has threaded interior bore 83 for receiving the seat holder 51 and holding the seat 43 it place. The splints 81 define respective passageways about the exterior of the seat assembly 47 and interiorly of the chamber 71.
Engagement of the seat 43 and the seat assembly with the ring poppet 45 of the nozzle 49 effects the desired rate of flow or closure to stop flow. The poppet 45 is formed of metal such as brass or the like, as is the rest of the nozzle 49, Fig. 3. us can be seen in Figs. 3-5, the nozzle 49 has a hexagonal, nut shaped section to facilitate being screwed into and from its conforming threaded bore in the boy 13. Its chamber 71, passageways 75, 77 and aperture 69 are illustrated. The aperture 69 has threaded shoulders leading into and therefrom and shown by frusto-conical and inverted frusto-conical sections I 89.
The usual materials and workmanship is employed in this invention. For example, the respective poppets, bushiTIgs, cartridge elements and the like may be formed from brass, stainless steel or other metallic materials appropriate to the type of gas being flowed therapist.
Where there is very little compressive and tensile stresses, the thermoplastic materials can be employed.
Typically thermoplastic materials may be Nylon, Onion, polyethylene, or the polyhalogenated hydrocarbon materials. It is desirable, however, that the upwardly extending centering extension shalt 55 have low friction with respect to the centering and dampening means 57, 33~

but not too low. Consequently, some care should be taken in selection of these materials. It has been found satisfactory to employ brass shaft 55 and a molded thermoplastic material for the friction damper, or centering and dampening means 5 57. While rlylon or other material can be employed, a particularly satisfactory, relatively new material is an improved Nylon impregnated with molybdenum disulfide, corr~nercially available from The Polymer Corporation, Reading, Pennsylvallia. It was chosen because it could be injection 10 molded more easily than Teflon, or other polyhalogenated hydrocarbon materials. The 0-rings may be formed from Neoprene or other conventional materials to give the desired elastomeric character. The valve seat may be formed of any Neoprene or any elastomeric material that is resistant to 15 corrosion and erosion by the gas being pressure regulated.
In operation, the low pressure regulator if is connected with a high pressure cylinder of gas (not shown) by inlet passageway 23 and appropriate conduit connection (also not shown). With zero pressure set by compression adjusting 20 means in regulator cap 15, the pressure in high pressure chamber 25, coupled with urging from spring 53, forces the seat assembly upward to engage the seat 43 with the ring poppet 45 and shut off flow of any gas.

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When the threaded stud 31 is screwed downward, pressure is applied to spring 17 and force is transmitted to unseat the seat it from the ring poppet I by force of the diaphragm means 19, bottom plate 35 and centering extension shaft 55. Outlet chamber 29; having already been connected with a suitable index function, such as cxvgen connection, welding torch or the live, has pressure build-up to a value determined by the degree of compression afforded by the spring 17. As pressure increases in the low pressure chamber 29, pressure acting on the diaphragm means 19 counterbalances the force of the spring 17 allowing the seat to be engaged by the poppet again and block the flow of fluid.
During the normal opening and closing of the seat with respect to poppet, the normal and destructive vibration that is frequently otherwise induced is dampened out by the centering and dampening means 57 frictionally engaging the shaft 55.
Once the device employing the fluid from the outlet begins to operate; as by taking oxygen by welding torch, oxygen mass, tent or the like; pressure decreases unbalancing the force opposing springs 17 which again depresses the seat assembly, opening flow passageway between the poppet seat. Gases flow upwardly through the chamber 71 and out the passageway 77 of the nozzle 49. Flow of fluid continues until the pressure begins to balance the forces again. The flow of fluid may be greater or lesser amo~mts. In every flow situation, the regulator of this invention substantially I eliminates the destructive and noisy vibrations and always alleviates problems that are normally introduced in regulators regulating flow from high pressure into a low pressure.
One of the advantages of this invention is that it can be employed in substantially any type of regulator, such as the AR-type regulators illustrated in Fig. 1, I

the line, or L-type regulators such as illustrated in Fig. 8, or the stationary, or S-type regulators illustrated in Fig. 9.
In the AR-type, air relieving, regulators that S provide automatic bleed-off, the centering and dampening means serve both to dampen and to keep the stem centered so that the top of the stem shuts off against the center aperture 91. Frequently, an O-ring is employed in the center aperture to insure shut off. This I requires a good alignment. The double guide alignment in accordance with this invention ensures alignment with the self relieving aperture in the center of the AR diaphragm.
Referring to the other embodiments of this invention and in particular to Fig. 8, the reference numerals illustrate substantially the same sub-assemblies and only a partial cross-sectional view is shown with the bottom of the housing cap and body of the regulator are shown. In the AR-type regulators illustrated in Fig.
1, the plate 35 has a center aperture 91 such that pressure is relieved in the low pressure chamber 29 when the aperture 91 is backed off the top of the shaft 55. On the other hand, the top of the shaft 55 encounters the aperture 91, flow is blocked and the pressure operates normally. The advantage of this is that the low pressure is relieved to atmosphere through passageways 93 in the housing cap 15. In the embodiment of Fig. 8, although the passageway 93 are shown in the cap 15, there is no center aperture so the pressure in the low pressure chamber 29 remains trapped. In all the embodiments of the regulators, an O-ring 95 seals about the nozzle I when it is threaded into its receptacle.
The operation of the embodiment of Fig. 8 is substantially the same as that described with respect to Fig. 1 except for the air relieving bleed-off through the central aperture 91.

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'l -14-In the embodiment of Fig. 9, the same reference numerals are employed to designate the same sub-assemblies and elements as described herein before with respect to Fig. 1. The major difference in the embodiment of Fig.
9 prom jig. 8 is that the entry passageway 23 is at the bottom, or rear, of the regulator whereas Fig. 8 has entry from the side, similarly as did Fig. 1. In Fig.
9, there is no central aperture 91, similarly as there was not with respect to Fig. 8. Otherwise, the operation Ox the embodiment of Fig. 9 is substantially the same as the operation of the embodiment of Fig. 1.
In particular, this invention provides a frictional dampening in combination with a nozzle and a seat holder, the combination of the centering and upwardly protruding shaft and the centering and dampening means serving to prevent oscillations and dampen out noisy and self-destructive vibrations. A particular combination ox the movable fingers in combination with the O-ring disposed about the body and bearing against the fingers, creates just the right degree of drag and eliminate chatter and instability without inducing high coefficient of friction that would inhibit operation of the regulator.
Moreover, the centering and dampening means serves as a guide, actually acting as a double guide in combination with the aperture in the nozzle and the seat retaining ring and the spring 79 pushing upwardly on the seat assembly I
While the invention herein has been described and illustrated with respect to a movable ring seat sealing against a fixed ring poppet, the arrangement can be reversed and the poppet moved, similarly as described in United States Patent No. BYWAY.
prom the foregoing, it can be seen that this invention achieves the objects set out herein before.
Although this invention has been described with a certain degree ox particularity, it is understood that 'I f~33~
-aye-the present disclosure is made only by way of example and that numerous changes in the details of construction and the combination and arrangement of parts may be resorted to without departing from the spirit and the scope of the invention, reference being had for the latter purpose to the appended claims.

Claims (12)

What is claimed is:

1. In a pressure regulator for reducing pressure of a fluid from a high pressure to a low pressure and including:
a. a valve body having inlet and outlet passageways and chambers;
b. a valve seat and valve poppet for sealingly engaging and disposed intermediate said inlet and outlet chambers for selectively allowing flow and sealing off flow of said fluid flowing from the higher pressure to the lower pressure;
c. adjustable spring with a bottom plate for adjusting the low pressure; and d. diaphragm communicating with said outlet chamber having said low pressure so as to sense said low pressure and opposing said adjustable spring so as to allow said valve poppet and said valve seat to move together when the pressure becomes great enough and to open when said low pressure is below the predetermined pressure set on said adjustable spring;
the improvement comprising:
e. having one of said seat and poppet include a centering extension shaft extending to the low pressure side of said valve seat and having a larger diameter slideable base slideably disposed in communication with the inlet chamber and said high pressure therewithin;
said centering extension shaft extending through a centering orifice and into contact with said diaphragm member for effecting opening and closing responsive to movement of said diaphragm member;
f. centering and dampening upper protrusion means for centering and dampening; said upper protrusion means encompassing said centering extension shaft;
said centering and dampening upper protrusion including a body portion disposed circumferential about said centering extension shaft and including a plurality of dampening fingers; said plurality of fingers comprising at least two fingers as defined by at least two slots disposed substantially uniformly thereabout; and an O-ring disposed about said dampening fingers and adapted to compress said dampening fingers into dampening engagement with said centering extension shaft of said poppet so as to prevent excessive instability and dampen out instability vibrations when said fluid flows about said centering extension shaft.

2. The pressure regulator of claim 1 wherein said centering and dampening upper protrusions includes at least two slots diametrically opposite each other and said fingers and surrounding O-ring are formed of thermoplastic material and elastomeric material, respectively.

3. The pressure regulator of claim 2 wherein said centering and dampening upper protrusion includes four said slots disposed substantially uniformly about said centering extension shaft.

4. The pressure regulator of claim 2 wherein said seat is a movable ring surrounding said centering extension shaft so as to move longitudinally with said shaft and said poppet comprises a stationary metallic ring that engages said ring that engages said ring seat for shutting off flow of gas when the pressure becomes high enough.

5. The pressure regulator of claim 1 wherein a nozzle assembly is screwed into said body and said centering extension shaft extends through said orifice in the superstructure of said nozzle with a fluid flow passageway annularly about said centering extension shaft with effluent passageways for conducting said fluid into said low pressure chamber; and said seat assembly is slideably disposed in the skirt of said nozzle so as to move said ring seat into and out of engagement with the stationary ring poppet which is disposed in the superstructure of said nozzle, for controlling the flow of fluid flowing from said high pressure to said low pressure.

6. The pressure regulator of claim 5 wherein a second spring is disposed beneath said seat assembly to co-act with high pressure to push said seat assembly into engagement with said ring poppet for stopping the flow of fluid when the pressure gets high enough in said outlet chamber;
and said centering extension shaft is adapted to engage said diaphragm and said bottom plate of said adjustable spring so as to open said valve seat from said poppet when said low pressure becomes too low.

7. A pressure regulator for reducing pressure of a fluid flowing from a high pressure to a low pressure comprising:
a. valve body having inlet and outlet passageways and chambers;
b. a valve cap including adjustable spring for adjusting the flow of pressure and having a bottom plate; diaphragm means communicating with a low pressure chamber and contiguous the bottom plate on said adjustable spring and opposing said adjustable spring so as to allow a valve poppet and seat to be brought together when the pressure becomes great enough and close off flow and to open said poppet and seat so as to allow flow when the pressure is too low;
c. an improved cartridge that includes said poppet and seat adapted for relative reciprocal movement therebetween; one of said poppet and seat including a centering extension shaft extending to the low pressure side of said seat and a larger diameter shaft in communication with a high pressure inlet chamber and slideably disposed so as to allow flow of fluid therepast, yet move reciprocally with said centering extension shaft; said centering extension shaft extending through a centering orifice and in to contact with said diaphragm member for effecting opening and closing movement between said poppet and seat responsive to movement of said diaphragm member;
d. centering and dampening upper protrusion means for centering and dampening; said centering and dampening upper protrusion means encompassing said centering extension shaft;
said centering and dampening upper protrusion including a body portion disposed circumferentially about said centering extension shaft including a plurality of dampening fingers; said plurality of fingers comprising at least two fingers as defined by at least two slots disposed substantially uniformly thereabout; and an O-ring disposed about said dampening fingers and adapted to compress said dampening fingers into dampening engagement with said centering extension shaft of said poppet so as to prevent excessive instability and dampen out instability of vibrations when said fluid flows about said centering extension shaft.

8. The pressure regulator of claim 7 wherein said centering and dampening upper protrusion means includes at least two slots diametrically opposite each other and said fingers and surrounding O-ring are formed of thermoplastic material and elastomeric material, respectively.

9. The pressure regulator of claim 2 wherein said centering and dampening upper protrusion includes four sets of slots disposed substantially uniformly about said centering extension shaft.

10. The pressure regulator of claim 7 wherein said seat is a movable ring surrounding said centering extension shaft so as to move longitudinally with said shaft and said poppet comprise a stationary metallic ring that engages said ring seat for shutting off flow of gas when pressure becomes high enough.

11. The pressure regulator of claim 7 wherein a nozzle assembly is screwed into said body and said centering extension shaft extends through said orifice in the superstructure of said nozzle with a fluid flow passageway annularly about said centering extension shaft with effluent passageways for conducting said fluid into said low pressure chamber; and said seat assembly slideably disposed in the skirt of said nozzle so as to move said ring seat into and out of engagement with a stationary ring poppet which is disposed in the superstructure of said nozzle, for controlling the flow of fluid flowing from said high pressure to said low pressure.

12. The pressure regulator of claim 11 wherein a second spring is disposed beneath said seat assembly to coact with high pressure to push said seat assembly into engagement with said ring poppet for stopping the flow of fluid in combination with said diaphragm and spring, when the pressure gets high enough in said outlet chamber; and said centering extension shaft is adapted to engage said diaphragm and said bottom plate of said adjustable spring so as to open said valve seat from said poppet when said low pressure becomes too low.