Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16K—VALVES; TAPS; COCKS; ACTUATING-FLOATS; DEVICES FOR VENTING OR AERATING
  • F16K5/00—Plug valves; Taps or cocks comprising only cut-off apparatus having at least one of the sealing faces shaped as a more or less complete surface of a solid of revolution, the opening and closing movement being predominantly rotary
  • F16K5/06—Plug valves; Taps or cocks comprising only cut-off apparatus having at least one of the sealing faces shaped as a more or less complete surface of a solid of revolution, the opening and closing movement being predominantly rotary with plugs having spherical surfaces; Packings therefor
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16K—VALVES; TAPS; COCKS; ACTUATING-FLOATS; DEVICES FOR VENTING OR AERATING
  • F16K5/00—Plug valves; Taps or cocks comprising only cut-off apparatus having at least one of the sealing faces shaped as a more or less complete surface of a solid of revolution, the opening and closing movement being predominantly rotary
  • F16K5/06—Plug valves; Taps or cocks comprising only cut-off apparatus having at least one of the sealing faces shaped as a more or less complete surface of a solid of revolution, the opening and closing movement being predominantly rotary with plugs having spherical surfaces; Packings therefor
  • F16K5/0663—Packings
  • F16K5/0684—Packings on the plug

Definitions

• the present invention relates to a valve with ball of controlled deformation.
• Ball valves are fluid shut-off devices which are widely used in all types of processes and all branches of engineering. These ball valves are used, for example, in water, oil, gas transport systems, in hydrocarbon production plants, in chemical, petrochemical plants and in electrical energy generating equipment.
• ball valves are available and may be used in a wide range of sizes, from the smallest to those which exceed 60 for pressures up to hundreds of bars.
• shut-off devices i.e. ball valves
• the fluid seal is effected between the ball and the two seats, each of which is equipped with a circular insert of deformable material which is clamped between the two metal surfaces.
• the function of the inserts is to compensate, by their own deformations, for the elastic deformations, the small geometrical errors and the roughnesses which are always present on the surface of the ball.
• the inserts are normally made of elastomeric (nitrite, viton etc.) or thermoplastic (PTFE, nylon etc.) material which can ensure optimum performance (i.e. high levels of sealing) as long as the operating conditions do not become particularly onerous.
• onerous and limit conditions examples include those which may be caused by the presence of particularly "dirty" fluids which entrain abrasive particulates.
• a further example of onerous conditions is one in which the valve is required to operate for a prolonged period in the partially open condition, with the fluid which, flowing at high velocity, violently laps the insert or conditions in which high temperatures are present.
• the metal surfaces of the seats and of the ball, which are to provide the seal and on which the reciprocal sliding takes place, are hardened for this purpose, by heat-treating the base materials.
• these surfaces may be provided with hard superficial facings obtained by welding or other more advanced technologies (plasma, HNOF etc.).
• the object of the invention is therefore to provide a ball valve in which it is possible to obtain a very tight seal even when the ball valve is subjected to particularly high pressure.
• a further object of the invention is to provide a ball valve which, while remaining very simple in structure and of modest cost, fully meets the operating and sealing performances which are necessary and required.
• a valve with ball of controlled deformation for fluid shut-off comprising an external containment body, inside which is arranged a shutter element, movable between a closure position and an opening position of the valve, the shutter element cooperating with one or more seats and providing for seal elements with respect to the containment body and to the shutter element, characterized in that the said shutter element provides for yielding zones in its spherical portions disposed downstream of the said seats with respect to a pressure zone.
• valve provides that the said yielding zones are provided by notches produced on surface zones of the said shutter element in correspondence with the said spherical portions.
• the said notches are substantially produced according to a direction parallel to an axis of rotation of the said shutter element.
• Fig. 1 is a partial view of a valve with ball according to the prior art, partly a view, partly a sectional view, in which the stresses are shown, and the deformation of the parts in dotted lines;
• Fig. 2 is a view of an enlarged detail of Fig. 1;
• Fig. 3 shows a lateral elevation on a smaller scale of a shutter element according to the invention in a first embodiment thereof
• Fig. 4 is a view, half of which is sectional according to TV-IV of Fig. 3 and half a side view;
• Fig. 5 is a view of part of a shutter element of a valve with ball according to the invention of Fig. 3, showing stresses and deformations of the parts;
• Fig. 6 is a further, partial view of the shutter element of Fig. 3, partially mounted;
• Fig. 7 is a lateral elevation on a smaller scale of a shutter element according to the invention, in a second embodiment thereof;
• Fig. 8 is a sectional view according to VIII-VIII of Fig. 7;
• Fig. 9 is a lateral elevation on a smaller scale of a shutter element according to the invention in a third embodiment thereof;
• Fig. 10 is a sectional view according to X-X of Fig. 9;
• Fig. 11 is a lateral elevation on a smaller scale of a shutter element according to the invention in a fourth embodiment thereof;
• Fig. 12 is a sectional view according to XI-XI of Fig. 11,;
• Fig. 13 is a lateral elevation on a smaller scale of a shutter element according to the invention in a fifth embodiment thereof;
• Fig. 14 is a sectional view according to XIN-XIV of Fig. 13.
• a valve with ball of controlled deformation is shown in a series of exemplary embodiments in which the shutter element varies.
• Figs. 3-6 show a first embodiment of a valve with ball of controlled deformation according to the invention which primarily comprises an external containment body, shown as 11, on which a pair of ring seats 12 disposed on opposite sides is placed. These ring seats 12 are in fact positioned on opposite sides towards an inlet pipe and respectively an outlet pipe of the fluid which passes into the valve and /or is shut off by it.
• the valve further receives a shutter element, denoted overall by 13, which is rotatable by means of a control shaft, not shown, which may be connected to appendices 14 disposed perpendicular to the above-mentioned pipes.
• the shutter element 13 is of the ball type and is movable between a closure position and an opening position of the ball valve.
• Viewed with respect to the appendices 14, on opposite sides the lateral surface of the ball may provide spherical portions 15 suitable for engaging on surfaces 16 of the two ring seats 12.
• the further two opposite parts are flat and apertures 17 which connect a central hole 18 for the passage of the fluid are produced on them.
• the ring seats 12 may of course be shaped in different ways so as to adapt to the particular positioning and they may provide for the positioning of suitable seal elements which are not shown.
• notches 19 and 20 are produced on opposite sides, at the top and the bottom, between the spherical portions 15 and the central zone of the body of the shutter element so as to provide a kind of capped portions 15a and 15b. These notches 19 and 20 penetrate for a certain variable length L inside the spherical portions in a direction parallel to an axis R of rotation of the shutter element. These notches 19 and 20 are produced in zones in proximity to the appendices 14.
• Fig. 5 which shows half of the shutter element 13 produced according to the invention in its first embodiment, further shows how the stresses act and how the parts deform, in a theoretical line.
• Fig. 5 shows the curve (erj) which qualitatively shows how the circumference of theoretical contact deforms axially between the spherical portion of a known shutter element and the ring seat 12, denoted here by (d). From the drawing it can be seen that the maximum difference of the axial movements due to stresses is denoted by ⁇ hrj.
• curve (ei) shows the axial deformation of (d) when the geometry of the shutter element in its capped portion is modified according to the invention by the production of the notches 19 and 20.
• the spherical part of the shutter element is modified by increasing the deformability in the two zones, upper and lower, close to the appendices or hubs 14.
• the notch 19 and 20 has a base 21 of curvilinear shape.
• FIGs. 7 and 8 show notches 19 and 20 which have a base 22 of rectilinear shape.
• Figs. 9 and 10 show a third embodiment of shutter element according to the invention in which the opposing notches are Joined together to produce a circular notch 23.
• the spherical caps which derive therefrom are thus suspended on a circular central portion of smaller diameter 24, in the manner of a mushroom.
• Figs. 11 and 12 show a fourth embodiment of shutter element according to the invention in which, as in the preceding embodiment, a notch 25 is produced along the entire spherical portion 15.
• This notch 25 is variable in depth so that the spherical caps which derive therefrom are suspended on a central portion of smaller dimension 26, shaped like an ellipse and having the larger axis directed perpendicular to the axis of rotation R of the shutter element 13.
• FIG. 13 and 14 in which a fifth embodiment differs in that the central portion 26' is also elliptical but rotated through 90° with respect to the preceding one.
• a peripheral notch may also be produced according to a different profile so as to provide a central portion of smaller dimension which is differently shaped.
• a ball valve according to the invention therefore offers a valid solution to the technical problems raised by the shutter elements of the prior art.
• the presence of notches in the spherical portions causes these zones to even out the elastic deformations, under pressure, when brought into contact with the respective seats.
• notches as shown in Fig. 6, should be produced downstream of the seat 12 or downstream of the pressurized zone, in a zone denoted by X.
• the notch or relieving may have different types of geometries, as a function of the dimensions of the spherical portions and as a function of working pressure levels or other specific parameters.
• a technical solution such as that of the invention may therefore be applied to any type of ball valve.
• the special geometry of the shutter element in its spherical portions may be produced of metallic material, on the basis of a body which has been cast, forged, rolled or assembled by welding or directly of suitably selected plastics or composite materials.

Landscapes

• Engineering & Computer Science (AREA)
• General Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Taps Or Cocks (AREA)
• Fuel-Injection Apparatus (AREA)

Priority Applications (8)

Applications Claiming Priority (2)

Publications (1)

Family

ID=11380826

Family Applications (1)

Country Status (13)

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Citations (4)

Family Cites Families (4)

• 1998
  • 1998-10-07 IT IT1998MI002157A patent/IT1302619B1/it active IP Right Grant
• 1999
  • 1999-08-30 CA CA002313207A patent/CA2313207C/en not_active Expired - Fee Related
  • 1999-08-30 EP EP99939562A patent/EP1034391B1/en not_active Expired - Lifetime
  • 1999-08-30 BR BR9906851-6A patent/BR9906851A/pt not_active IP Right Cessation
  • 1999-08-30 RU RU2000114630/06A patent/RU2249744C2/ru not_active IP Right Cessation
  • 1999-08-30 AT AT99939562T patent/ATE258286T1/de not_active IP Right Cessation
  • 1999-08-30 US US09/555,910 patent/US6695286B1/en not_active Expired - Fee Related
  • 1999-08-30 SK SK833-2000A patent/SK286206B6/sk not_active IP Right Cessation
  • 1999-08-30 JP JP2000574858A patent/JP4441119B2/ja not_active Expired - Fee Related
  • 1999-08-30 WO PCT/IB1999/001490 patent/WO2000020783A1/en not_active Ceased
  • 1999-08-30 DE DE69914301T patent/DE69914301T2/de not_active Expired - Lifetime
  • 1999-09-27 AR ARP990104868A patent/AR020663A1/es active IP Right Grant
• 2000
  • 2000-05-30 ZA ZA200002706A patent/ZA200002706B/en unknown

Patent Citations (4)

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