GB2295442A

GB2295442A - Throttle valve

Info

Publication number: GB2295442A
Application number: GB9522587A
Authority: GB
Inventors: Christian Bull Eriksson
Original assignee: RC SUBSEA AS
Current assignee: RC SUBSEA AS
Priority date: 1994-11-04
Filing date: 1995-11-03
Publication date: 1996-05-29
Also published as: NO180467C; NO944204L; GB9522587D0; NO180467B; NO944204D0

Abstract

A pre-adjustable, connectable and disconnectable flow-limiting or throttle valve comprises a valve housing (1) having an inlet (28), an outlet (34) and an intermediate through flow channel in which a valve body is disposed. It has, especially, been aimed at avoiding clogging and, in this respect the valve body (36) is freely placed within the through flow channel which comprises a first narrow channel section (30) surrounding the valve body to provide normal flow conditions (36) with an insignificant clearance, and a second, substantially wider channel section (32) for cleaning, a stop means (38) being disposed within the valve housing (1), against said stop means (38) the valve body (36) will be resting irrespectively of within which channel section the valve body (36) is staying. Said stop means (38) and said through flow channel (30, 32) are relatively displaceable in an axial direction, so that the freely supported valve body (36) can be moved between the narrow channel section and the wide channel section. Instead of the valve moving it is possible in a second embodiment to move the housing. <IMAGE>

Description

THROTTLE VALVE The invention relates to a preadjustable, connectable and disconnectable flow-limiting valve or throttle valve, comprising a valve housing having an inlet, an outlet and an intermediate through flow channel in which a valve body is disposed.

Particularly, the invention concerns a flow-limiting valve or a throttle valve for use in injection systems for fluids, a special case of application for the invention occuring in connection with submarine admixture of chemicals during the recovery of oil.

It has been problematic to throttle fluids containing particular impurity materials, and also to open the valve for a large through flow in a desired period of time.

For said general objects, it is known to use adjustable valves or shunt valves.

disadvantage of known valves is that they are liable to be clogged through impurity materials, and cleaning of valve body and internal valve housing faces is time-consuming and very expensive and puts the valve out of operation during the cleaning. Of course, partly clogged valves do not function according to their purpose.

Therefore, the object of the present invention has been to avoid clogging during normal operation, simultaneously adapting the throttle valve according to the inventionto open for a considerable larger flow through the channel than during normal operation, in order i.a. to cause selfcleaning and exclude clogging completely.

In accordance with the invention, said objects are realized by shaping and designing a flow-limiting or throttle valve in conformity with the introduction section, according to the characterizing clause of the following claim 1.

Advantageous detail features of the invention are defined in the following dependent sub claims.

According to the invention, a preferably ball-shaped valve body is freely disposed in said through flow channel which has at least two longitudinal sections, a first section (the orifice) having a diameter only insignificantly exceeding the largest cross-sectional measure of the valve body, within said first channel section an essential portion of the valve body will be positioned during normal operation, and a second channel section joining said first channel section, said second channel section having a substantially larger diameter than the largest cross-sectional measure of the valve body, within said second channel section the valve body is brought to be positioned when a large flow of fluid through the through flow channel is needed.In both main positions for the valve body, the valve body rests against a stop means, the land area of which for the valve body facing in the opposite direction to the fluid flow direction.

In one embodiment for the invention, said stop means may be axially displaceably disposed in the valve housing, the through flow channel with the two sections thereof being stationarily formed in the interior of the valve housing.

It is assumed that the valve body is located within the first channel section. Upon a displacement of the stop means which for this purpose may be connected to a single-acting hydraulic piston cylinder, the cylinder thereof being formed in the valve housing, the valve body being moved by means of the fluid flow into the substantially widened, second channel section, thus enabling he through flow channel to be washed through, causing self-cleaning of the valve body, internal walls within the through flow channel and adjacent inner faces.

In another embodiment the valve body is stationary, a pipe piece within which the through flow channel's first and second sections are formed being axially displaceably disposed, said pipepiece may be connected to a corresponding piston cylinder as in the first examplary embodiment. The pipe piece with the internal through flow channel thereof is moved between two extreme positions, in the first of which the pipe piece's narrow channel section practically surrounds the valve body, in the second extreme poistion the wide channel section of the pipe piece surrounds the valve body, which in both positions is kept pressed against the staionary stop means by means of the fluid flow, and where first position represents normal operation, second position representing a sort of bypass condition in the throttle valve.

The free dipositing of the preferably ball-shaped valve body causes the valve body to vibrate when it is influenced by the fluid flow. This vibration causes particles of impurity materials to be crushed between the valve body and the surrounding internal channel-defining face. This particle crushing contributes in a substantial degree to avoid clogging. In order to exclude the clogging risk completely, said bypass or through-washing condition is established at a point of time chosen, before clogging in greater or less degree already has occured.

The valve body according to the present invention is preferably ball-shaped. However, the valve body would be capable of carrying out the intentional function thereof according to other, modified shapes and designs: a circlecylindrical piece of rod, an ellipsoidal body, a body consisting of two interhinged, opposite, conical bodies, etc., possibly with roundings.

Examples of possible embodiments are further explained in the following with reference to the accompanying drawings, in which: Figure 1 and 2 show axial sections through a valve housing wherein a stop means for a freely disposed valve body is displaceably disposed in the axial direction by means of a hydraulic piston cylinder operated by means of pilot pressure, and wherein:: Figure 1 shows said stop means in the position it occupies when the valve body, resting against the former due to the fluid flow, is situated within a narrow section of a through flow channel, corresponding to normal operation, and Figure 2 shows said stop means in the position it takes when the valve body, resting against the former due to the fluid flow, is situated within a channel section substantially wider than said narrow section, to which said wider channel section is connected, corresponding to the bypass condition of the throttle valve; Figure 3 shows, on a substantially larger scale than in figures 1 and 2, an area comprising an important portion of the through flow channel, and in which the valve body is situated within the narrow channel section according to figure 1, resting against the stop means;; Figures 4 and 5 show axial sections corresponding to figures 1 and 2, but illustrate a second embodiment where the stop means is stationary, a pipe piece within which the through flow channel at least partly has been formed, being axially displaceably disposed by means of a pilot pressure operated, hydraulic piston cylinder in a way corresponding to the embodiment of figures 1 - 3; Figure 6 shows, on a substantially larger scale than figures 4 and 5, the area defining the through flow channel, wherein the valve body is situated within the narrow channel section according to figure 4, and rests against the stop means, which in this case is stationary.

First, reference is made to the embodiment of figures 1 - 3: A valve housing 10 surrounds an internally graduated cylinder 12 incorporated within a single-acting hydraulic piston cylinder, the piston thereof being denoted at 14 and a return spring at 16, said piston cylinder being operated with pilot pressure through a gate 18. The spring 16 is disposed within a closed spring space 20 which, moreover, is formed to receive balancing fluid through a longitudinal channel 22 through the piston 14, which is communicating with a lateral upstream channel 24 and an adjacent annulus 26.

Moreover, the flow-limiting valve or throttle valve according to the invention comprises an inlet 28 communicating with a through flow channel 30,32 having an upstream, narrow section 30 and a downstream, substantially wider channel section 32. The outlet is denoted with the reference numeral 34. Said balancing channel 22 within the piston 14 with associated annulus 26 and lateral channel 24 prevent the pressure spring 16 of the piston 14 from being unintentionally compressed when fluid is let into the valve through the inlet 28.

Within the through flow channel 30,32 a ball-shaped valve body 36 is freely disposed. During normal operation, figure 1, the valve body 36 will be kept at the transition between the through flow channel's 30,32 narrow section 30, which has a diameter only quite insignificantly exceeding the diameter of the valve body 36, and the widened channel section. When using a valve body not directly ball-shaped, the narrow channel section 30 will have a diameter only unsignificantly exceeding the largest cross-sectional measure of such valve body.

In order to keep the valve body 36 within the narrow channel section 30 according to the invention, a stop means 38 has been disposed within the valve housing, the land area 38' thereof for the valve body 36 is facing in the opposite direction to the fluid flow direction in the area of the through flow channel 30,32.

In this first embodiment, figures 1 - 3, the stop means 38 is axially displaceably disposed, it being connected with the piston 14 which has an annular shoulder face 14' forming a reaction face for hydraulic pilot pressure through the gate 18, so that the piston 14 and, consequently, the stop means 38, against the action of the spring 16, are displaced from the normal operational position shown in figures 1 and 3 to the bypass position shown in figure 2, where the valve body 36 is located within the wide section 32 of the through flow channel where the through flow is sustantial.In first position, in which crushing of particles of polluting materials/ extraneos matter is secured through the vibration of the valve body, during which vibration the valve body strikes against the adjacent, channel-defining inner wall, thorough washing of the interior of the valve being secured in second position, causing self-cleaning of valve body and adjacent faces, possibly injecting maximum dosage.

In figures 1 and 2, a course or gate is denoted at 40, said gate extending from the piston jacket to the valve housing jacket, and forming a ventilation gate which is intended to be used when the throttle valve is used submarinely.

Reference numeral 42 denotes a lateral pin preventing the ball-shaped valve body 36 from leaving the through flow channel in a direction which, normally, is upstream. A number of packers not allotted reference numerals, are intended to prevent penetration of seawater with a submarine application of the flow-limiting or throttle valve according to the invention.

The second embodiment shown in figures 4 - 6 has many features of resemblance with first embodiment of figures 1 - 3, and identical or functionally equivalent parts and members, channel portions, gates, etc. are denoted by means of the same reference numerals as in figures 1 - 3 plus the small letter a. Thus, the valve housing is indicated at 10a.

In connection with the present invention, it is a general requirement that there exists a relative displacement between the stop means 38 and the through flow channel sections 30, 32 in the axial directions. According to figures 1 - 3, the through flow channel sections 30, 32 are stationary, the stop means 38 being displaceable.

According to the embodiment shown in figures 4 - 6, the relative displaceability between the stop means 38a and the through flow channel sections 30a, 32a in the axial direction is realized by maintaining the stop means 38a stationary, the through flow channel sections 30a, 32a being defined within a pipe piece which does not exist in the embodiment of figures 1 - 3; therefore, the pipe piece is allotted a new reference numeral 44 of its own. The pipe piece 44 is firmly screwed to the right end of the piston 14a, so that the through flow channel sections 30a, 32a are axially displaceable. Another difference between the embodiments consists in that the inlet 28a is radial, the inlet 28 of the first embodiment being axial.

The stationary dispositing of the stop means 38a and the displaceability of the pipe piece 44 between the position according to figure 4 where the valve body 36a is brought to take a position within the narrow channel section 30a, and the position according to figure 5 where the valve body 36a is brought to take a position within the wide channel section 32a, represent together with remaining features of resemblance a functional correspondence to the embodiment of figures 1 - 3.

Therefore, further explanation of the embodiment of figures 4 - 6 is considered to be superfluous.

Finally, it could be mentioned that between the cylindrical, narrow through flow channel section 30, 30a and the wide channel section 32, 32a, preferably, a conical transition channel portion 46, 46a is disposed, causing a gradual opening of the throttle valve when the valve body 36, 36a moves towards the wide channel section 32, 32a. Also, the stop means 38a may be displaceably disposed in order to vary the through flow.

Claims

1. A pre-adjustable, connectable and disconnectable flowlimiting or throttle valve, comprising a valve housing (10; l0a) having an inlet (28; 28a), and outlet (34; 34a) and an intermediate through flow channel, in which a valve body is disposed, c h a r a c t e r i z e d in that said valve body (36; 36a) is freely placed within the through flow channel which comprises a first, narrow channel section (30; 30a) surrounding the valve body (36; 36a), establishing an insignificant space therebetween, and another, substantially wider channel section (32; 32a), a stop means (38; 38a) being disposed, against which the valve body (36; 36a) will be resting irrespectively within which channel section it stays, and that said stop means (38; 38a) and said through flow channel (30,32; 30a,32a) are relatively displaceable in the axial direction, so that the freely supported valve body (36; 36a) can be moved between the narrow channel section (30; 30a) and the wide channel section (32; 32a).

2. A valve as set forth in claim 1, c h a r a c t e r i z e d i n that the valve body (36; 36a) is wholly or approximately ball-shaped.

3. A valve as set forth in claim 1 or 2, c h a r a c t e r i z e d i n that a conical transition portion (46; 46a) is disposed between the through flow channel's two coaxial channel sections (30, 32; 30a, 32a).

4. A valve as set forth in any one of the preceding claims, c h a r a c t e r i z e d i n that said stop means (38) whose land area (38') for the valve body (36) is facing against the fluid flow direction, is axially displaceably supported in order to allow the movement of the valve body (36) between the two sections (30, 32) of the through flow channel.

5. A valve as set forth in claim 4, c h a r a c t e r i z e d i n that the stop means (38) is operatively connected to a piston (14) of a pressure fluid operated piston cylinder (12,14), the cylinder (12) thereof being formed within the valve housing (1).

6. A valve as set forth in claim 5, c h a r a c t e r i z e d i n that the pressure fluid operated piston cylinder (12,14) is constituted by a single-acting hydraulic pressure cylinder having a return spring (16) in the form of a pressure spring, fluid communication from the through flow channel (30,32) at one axial end of the piston (14) and a spring-accommodating space (20) at the opposite axial end of the piston (14) being established, so that fluid pressure within the through flow channel not unintentionally can influence the degree of compression of the return spring (16).

7. A valve as set forth in any one of the preceding claims 1 - 3, c h a r a c t e r i z e d i n that said stop means (38a) is stationarily disposed, and that that the narrow and wide channel sections (30a, 32a) of the through flow channel are formed within a pipe (44), which is displaceably suspended in the axis direction in order to, through the stop means (38a), to bring the valve body (36a) to take a position within one or the other channel section (30a, 32a), the pipe preferably being connected to the piston (14a) of a pressure fluid operated piston cylinder (12a,14a) as defined in claim 5 or 6.

8. A valve as set forth in claim 7, c h a r a c t e r i z e d i n that said stop means (38a) is displaceably disposed.

9. A pre-adjustable, connectable and disconnectable flowlimiting or throttle valve substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.