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Title:
ROTATABLE BALL VALVE WITH AXIAL DISPLACEMENT ACTUATING STEM
Document Type and Number:
WIPO Patent Application WO/2020/005067
Kind Code:
A1
Abstract:
Valve (1) for controlling fluid flow with a valve ball (66) rotatable between an open position allowing fluid flow and a closed position in which a sealing surface in sealing contact with the entry port (3), exit port (4) or both blocks fluid flow. A valve ball actuating stem (10) is guided relative to the valve body (2) for axial guided movement and has a valve ball engagement section with actuating surfaces of helical shape so that axial displacement of the valve ball actuating stem (10) causes rotation of the valve ball (66). The guide strip members (71, 72) and the valve body (2) have complementary shapes mechanically guiding the guide strip members in the longitudinal direction thereof. One or more locking members (88) is/are provided for blocking dislodgement of the guide strip members in the longitudinal direction.

Inventors:
DANA, Jaroslav (C/O Farmsumerweg 43, 9902 BL Appingedam, NL)
Application Number:
NL2019/050399
Publication Date:
January 02, 2020
Filing Date:
June 28, 2019
Export Citation:
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Assignee:
CS BUSINESS SERVICES B.V. (Farmsumerweg 43, 9902 BL Appingedam, NL)
International Classes:
F16K5/06; F16K5/20; F16K31/524
Foreign References:
CH296102A1954-01-31
Other References:
CONTROL SEAL B.V. ET AL: "NON CONTACT RISING STEM BALL VALVE", 16 November 2016 (2016-11-16), pages 1 - 2, XP055566761, Retrieved from the Internet [retrieved on 20190308]
Attorney, Agent or Firm:
WITMANS, H.A. (V.O, P.O. Box, 2508 DH Den Haag, 87930, NL)
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Claims:
Claims

1. A valve for controlling fluid flow, the valve comprising:

a valve body with an entry port, an exit port and a sealing surface;

a valve ball in the valve body with a passage extending through the valve ball, wherein the valve ball is suspended in the valve body for rotation about a vertical axis of rotation between

- an open position, in which the entry port and the exit port are in fluid communication via the passage and a clearance is left between the valve ball and the valve body allowing fluid to flow from the entry port to the exit port between the valve ball and the valve body, and

- a closed position in which at least the entry port or the exit port is free from the passage and the sealing surface is in sealing contact with the at least one of the entry port or exit port that is free from the passage, and

a valve ball actuating stem guided in the valve body for axial guided movement between a first position and a second position;

wherein the valve ball comprises a valve ball body and guide strip members mounted to the valve ball body on opposite sides of a valve ball actuating opening, the guide strip members having guide strip surfaces that are curved about mutually parallel axes of curvature in longitudinal direction of the guide strip members and face each other; and

wherein the valve ball actuating stem has a valve ball engagement section having a cross-section with mutually opposite and parallel actuating surfaces including sections of helical shape, such that if the valve ball actuating stem is axially displaced from the first position to the second position, successive line shaped sections of the actuating surfaces engage the guide strip surfaces and the valve ball is rotated from the open position to the closed position and vice versa if the valve ball actuating stem is axially displaced from the second position to the first position;

characterized in that, in cross-section perpendicular to the

longitudinal direction of the guide strip members, the guide strip members and the valve body have complementary shapes mechanically guiding the guide strip members in the longitudinal direction; and

at least one locking member is provided for blocking dislodgement of the guide strip members from the valve ball body in the longitudinal direction. 2. A valve according to claim 1, wherein play between the at least one locking member and the guide strip members is provided for allowing movement of the guide strip members relative to the valve ball body in the longitudinal direction. 3. A valve according to claim 1 or 2, wherein, in planes perpendicular to the longitudinal direction, the guide strip members have circular cross- sections.

4. A valve according to any of the preceding claims, wherein the at least one locking member is a ring extending around a portion of the valve ball body and longitudinal ends of the guide strip members.

Description:
Rotatable ball valve with axial displacement actuating stem

FIELD AND BACKGROUND OF THE INVENTION

The invention relates to a valve according to the introductory portion of claim 1.

Such valves are for instance used in the extraction from the earth and the processing of subterranean fluid natural resources such as oil and gas, for instance in drilling and production systems, transport pipelines and refineries. The valves are used to control the flow of fluids through pipelines in which the valves are mounted. In many applications, such valves operate under extreme conditions such as pressures between 5 and 25,000 bar, flow speeds of up to 800 m/s and temperatures of -196— 938 °C. For fire safety certification, such valves are for instance tested by heating to 900 °C, keeping the valve at that temperature for 20 minutes, opening and closing of the valve at that

temperature and then ten cycles of cooling to ambient temperature, reheating to the same temperature and opening and closing of the valve.

Although such valves are generally designated as ball valves having a valve ball that is rotatable between an open position allowing flow through the valves and a closed position blocking flow through the valve, the valve ball is typically not of an exactly spherical ball shape, but only generally ball shaped and generally provided with a passage through which fluid can flow if the valve ball is in the open position, sealing surfaces and slightly recessed surface portion, for instance shaped to stay clear of surfaces of a valve cavity in which the valve ball is located, while the ball is rotated.

An example of such a rotatable ball valve, which is known from practice and which is commercially available, is shown in Fig. 1. In this valve, the ball is actuated by a valve ball actuating stem of which a section engaging the valve ball has a cross-section with mutually opposite parallel valve ball actuating surfaces of which sections are shaped helically and that engage guide strip members of wear resistant metal that are welded to the valve ball body. The guide strip members have contact surfaces that are curved about mutually parallel axes of curvature. The contact surfaces of the guide strip members are also parallel to lines along the contact surfaces of the valve ball actuating stem where these surfaces are in contact with these surfaces of the guide strip members.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a valve which can be manufactured at lower costs and which has an increased life span, at least in applications in which the valve is subjected to fast and large temperature changes.

According to the invention, this object is achieved by providing a valve according to claim 1.

Because, in cross-section perpendicular to the longitudinal direction of the guide strip members, the guide strip members and the valve body have complementary shapes mechanically guiding the guide strip members in the longitudinal direction and at least one locking member is provided for blocking dislodgement of the guide strip members from the valve ball body in the longitudinal direction, the guide strip members are held in place relative to the valve ball body in a non-adherent manner, so the guide strip members can expand and shrink in response to temperature changes separately from adjacent portions of the valve ball body. Temperature changes of the valve ball body typically precede temperature changes of the guide strip members and the valve ball body material can have a different thermal coefficient of expansion than the material of the guide strip members. Because repeated thermal stress in the guide strip members and the adjacent portions of the valve ball body is substantially reduced, cracking of the guide strip members and the valve ball body is counteracted. Cracking of welding material is avoided, because the guide strip members are not welded to the valve ball body. The life span is particularly increased, because debris released as a result from cracking damages the surfaces of the valve ball actuating stem and the guide strip surfaces contacting each other.

Furthermore, manufacturing of the valve can be carried out more easily and at lower costs, because the need of welding of the guide strips is avoided.

Particular elaborations and embodiments of the invention as well as an example of a prior art valve are set forth in the dependent claims.

Further features, effects and details of the invention appear from the detailed description and the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 is a cross-sectional view along a vertical center plane of a prior art valve;

Fig. 2 is a cross-sectional view along a vertical center plane of an example of a valve according to the invention;

Fig. 3 is an enlarged view of a portion III of Fig. 2, and

Fig. 4 is a cross-sectional view along a plane IV- IV in Figs. 2 and 3. DETAILED DESCRIPTION

In Fig. 1, a valve 1 for controlling fluid flows which is commercially available is shown.

The valve 1 has a valve body 2 with an entry port 3 and an exit port 4. The exit port 4 extends through and is bounded by a valve seat member 5. In the valve body 2, a valve ball 6 having a sealing surface 14 is arranged. A passage 8 in the form of a bore extends through the valve ball 6.

The valve ball 6 is suspended in the valve body 2 for rotation about a vertical axis of rotation 9 via a valve ball suspension 10, 11. The valve ball 6 is rotatable between a closed position (shown in Fig. 1 and an open position (not shown in Fig. 1).

If the valve body 2 is in the open position, the entry port 3 and the exit port 4 are in fluid communication with each other via the passage 8 and a clearance 7 is left between the valve ball 6 and the valve body 2. Thus, fluid can flow both through the valve ball 6 and through the clearance 7 between the valve ball 6 and the valve body 2.

If the valve body 2 is in the closed position, the entry port 3 and the exit port 4 are free from the passage 8 and the sealing surface 14 is in sealing contact with the valve seat member 5 of the exit port 4.

The valve ball suspension includes a trunnion 11 at a bottom side of the valve ball 6 and a valve ball actuating stem 10 engaging the valve ball 6 for driving rotation of the valve ball 6 between the open and closed positions. The valve ball 6 rotates in response to axial movement of the valve ball actuating stem 10.

The valve ball actuating stem 10 is guided in the valve body 6 for axial guided movement without rotation between an uppermost first position (not shown) and a lowermost second position (shown in Fig. 1)

The valve ball 6 includes a valve ball body 20 and guide strip members 21, 22 mounted to the valve ball body 20 on opposite sides of a valve ball actuating opening 23, the guide strip members 21, 22 have guide strip surfaces 24, 25 that are curved about mutually parallel axes of curvature in

longitudinal direction of the guide strip members 22 (perpendicular to the drawing plane) and face each other. The axes of curvature are on sides of the respective surface located away from the actuating opening 23, i.e. the guide strip surfaces are rounded bulging on the side of the actuating opening 23.

The valve ball actuating stem 10 has a valve ball engagement section 25 having a cross-section with mutually opposite and parallel actuating surfaces. The actuating surfaces each have a section 26, 27 having a helical shape. If the valve ball actuating stem 10 is axially displaced from the uppermost first position (not shown), in which lowermost, line shaped portions of the actuating surfaces 26, 27 are in contact with the guide strip surfaces 24, 25, to the second position (shown in Fig. 1) in which uppermost, line shaped portions of the actuating surfaces 26, 27 are in contact with the guide strip surfaces 24, 25, successive line shaped sections of the actuating surfaces 26, 27 engage the guide strip surfaces 24, 25 and the valve ball 6 is rotated from the open position to the closed position and vice versa if the valve ball actuating stem

10 is axially displaced from the second position to the first position. Thus, the rotation of the valve ball 6 can be actuated without rotating the valve ball actuating stem 10. This is advantageous for reducing wear of the seal 28 between the valve ball actuating stem 10 and the valve body 2.

The valve actuating stem also has a section 31 in which sections 32, 33 of the actuating surfaces are essentially flat and oriented at a wedge angle relative to the longitudinal axis of the valve ball actuating stem 10. If the valvel is closed, these essentially flat actuating surface sections 32, 33 cause the valve ball 6 to be pivoted about the trunnion 11 against the valve seat 5 after the rotation has been completed. If the valve 1 is opened, these

essentially flat actuating surface sections 32, 33 cause the valve ball 6 to be pivoted about the trunnion 11 away from the valve seat 5 prior to the rotation of the valve ball 6. This allows the valve ball 6 to rotate free from the valve seat 5 while it is rotated and provides a reliable seal of the sealing surface 14 against the valve seat 5 if the valve is closed.

The trunnion 11 is fixed to the valve ball 6 and projects downwards through the clearance 7 into a bore 12 in the valve body 2. The bore 12 is lined with a lining 13 of a material which, when in sliding contact with the trunnion

11 is more wear resistant than the material of which a major portion of the valve body 2 is made. Suitable sliding bearing material combinations are commercially available. The axial movement of the valve ball actuating stem 10 may for instance be driven manually, e.g. by a hand wheel and a nut engaging a threaded part of the valve ball actuating stem (not shown) or by an electric or hydraulic motor.

The valve body 2 has flanges 29, 30 for mounting the valve to pipe sections upstream and downstream of the valve 1.

In Figs. 2-4, an example of a valve 51 according to invention is shown. Parts or portions 2-5, 8-14, 25-27 and 29-33 of the example that are identical to corresponding parts of the valve shown in Fig. 1 are designated by the same reference numbers as in Fig. 1.

Guide strip members 71, 72 have guide strip surfaces 74, 75, each in contact with one of the actuating surfaces 26, 27 of the valve ball actuating stem 10.

Seen in cross-section perpendicular to the longitudinal direction of the guide strip members 71, 72, the guide strip members 71, 72 and the valve ball body 70 have complementary shapes 84, 85 and 86, 87 which, together with the actuating surfaces 26, 27 of the valve ball actuating stem 10, mechanically hold the guide strip members 71, 72 against displacement transverse to the longitudinal direction. For blocking dislodgement of the guide strip members 71, 72 relative to the valve ball body 70 in the longitudinal direction, a locking member 88 is provided.

The guide strip members 71, 72 are held in place relative to the valve ball body 66 in a non-adherent manner, so there is no material adherence as in a welded, soldered or adhesively bonded joint. This allows the guide strip members 71, 72 to expand and shrink relative to the adjacent portions of the valve ball body 70 in a floating manner, so the expansion is not or to a much lesser extent inhibited than in a construction in which the guide members are for instance welded to the valve ball body and thermal stress in the guide strip members and the adjacent portions of the valve ball body is substantially reduced.

Differences in expansion and shrinkage occur frequently due to fast and large temperature changes caused by fluid flows passing through the valve and due to starting and stopping of such flows. The temperature of the fluid flow may fluctuate extremely and/or the temperature of a fluid flow that is started or stopped may be much higher or lower than the ambient temperature at the valve. Temperature changes of the valve ball body typically precede temperature changes of the guide strip members. Also, the material of the valve ball body may have a different thermal coefficient of expansion than the material of the guide strip members. Accordingly, due to the non adherent mounting of the guide strip members 71, 72, local movement of the the guide strip members 71, 72 relative to the valve ball body 70 is allowed. Thus, cracking of the guide strip members and the valve ball body 70 is

counteracted. Cracking of welding material is avoided, because the guide strip members 71, 72 are not welded to the valve ball body 70. The life span is particularly increased, because debris released as a result of cracking tends to damage the actuating surfaces of the valve ball actuating stem and the guide strip surfaces contacting each other.

Where normally a valve would for instance have a reliable life span of about 20.000 thermal cycles between ambient temperature and 900 °C, a valve according to the invention is expected to endure about 40.000 of such thermal cycles without failure of or at the guide strip members.

Moreover, such a valve can be manufactured at low costs, because the guide strip members 71, 72 can easily be slipped into the valve ball body 70 and do not need to be welded accurately in place to the valve ball body 70.

To allow the guide strip members 71, 72 to accommodate to temperature changes, some clearance may be provided between the locking member 88 or locking members and the guide strip members 71, 72 for allowing some movement of the guide strip members 71, 72 relative to the valve ball body 70 in the longitudinal direction. The amount of this clearance is preferably up to 3 mm and more preferably 0.1 to 2.5 mm depending on the size of the guide strip members and any difference in thermal expansion coefficients of the guide strip members 71, 72 and of the valve ball body 70. If, as in the present example, the guide strip members 71, 72 have circular cross-sections, also floating of the guide strip members 71, 72 in rotational sense about longitudinal axes thereof is allowed, which further reduces thermal stress. Moreover, rotation of the guide strip members 71, 72 about the longitudinal axes causes the surface portions 74, 75 in contact with the actuating surfaces 26, 27, 32, 33 to move in circumferential sense, so that wear of the guide strip members 71, 72 is more evenly distributed, which further contributes to increasing the life span.

In the present example, locking of the guide strip members 71, 72 in longitudinal direction relative to the valve ball body 70 is achieved in a particularly simple and efficient manner, by providing a ring 88 extending around a portion of the valve ball body 70 and longitudinal ends of the guide strip members 71, 72 as the locking member.

Valves according to the invention can be provided in a wide range of dimensions, but are particularly advantageous in applications involving the extraction from the earth and the processing of subterranean fluid natural resources such as oil and gas, for instance in drilling and production systems, transport pipelines and refineries. In such applications, generally, port diameters of about 2.5 to 90 cm are required.