DE2065787A1 - Annular seal of (glan filled) ptfe for - butterfly valve - Google Patents

Abstract

An annular seal ring with a bevelled face is clamped in the housing of a butterfly valve having a matching chamfer on its periphery. The seal ring is clamped between ribbed metal blocks and is replaceable. The valve itself is mounted on pivots turning in needled bearings protected by resilient seal rings. Pref. the seal is made of PTFE containing 12-18% wt. glass fibre filler-alternatively the seal may be a PTFE coating on a spring steel support.

Description

our reference: G 1369

4:
27

Rotary flap valve for pipelines ^ Separation from patent (P 20 10 632.5-Ϋ2)

The invention relates to a rotary flap valve for pipelines with one between two pipeline flanges to be clamped ring body, which has a substantially rotationally symmetrical passage for the flow medium has, a rotary flap rotatably mounted in the ring body, which is perpendicular to the axis of the passage in relation to it intersecting axis of rotation is offset, and with one of the inner wall of the annular body protruding slightly into the passage Seat ring which, in the closed position, interacts with a contact surface that extends around the circumference of the rotary valve. ·

There are, for example, from the OE-PS 235 097 and the US Pat. No. 3,282,558, rotary flap valves of this type are known in which the contact surface of the rotary flap is formed by an annular Section of a ball is formed, while the inner surface cooperating with it in the closed position

Lei / Gl

609823/0363

of the seat ring is an annular section of a conical surface. In these known rotary flap valves, however, the seat ring is made of rubber or an --elaste -, meren plastic, and the seal in the closed position is ensured by the elasticity of the material of the seat ring. This rotary damper valves operate satisfactory, if: operating conditions _..-:; (Temperature, pressure, nature of the _: fluid correspond to the properties of the material of the elastic seat ring. In numerous applications, however, elastic seat rings made of rubber or a rubber-like plastic do not have a sufficient service life; this applies in particular if the rotary valve valve. must work at high temperatures or high pressures, or if the seat ring is exposed to aggressive or abrasive fluids, -.,. -.

It is also known (PR-PS 1 365 570), with rotary flap valves, the type specified to produce the seat ring from polytetrafluoroethylene, .This material has excellent resistance to high temperatures, large. Pressing and aggressive or abrasive Media on. However, polytetrafluoroethylene has the property that it is subject to mechanical. Load flows; Using has this material for seat rings of butterfly valves This means that a good sealing initially achieved in the closed position with a sufficiently high closing pressure. effect is lost over time because the polytetrafluoroethylene flows away from the contact point between the seat ring and the rotary valve under the closing pressure.

The object of the invention is to create a butterfly valve of the type specified at the beginning, which is used at high temperatures, high pressures and for aggressive or abrasive

0 9 8 2 3/0383 ORIGINAL INSPECTED

20657J7

Fluid is usable and still a good one Sealing effect guaranteed over long periods of time and frequent actuation of the rotary flap valve.

According to the invention, this object is achieved by the combination of the following features:

a) the contact surface of the rotary valve is through a section formed a sphere whose center is at the intersection of the axis of the passage and the Axis of rotation of the rotary flap is located;

b) the seat ring is made of a material based on polytetrafluoroethylene and is in an annular shape Grooved in the ring body;

c) in the closed position with the contact surface of the Rotary valve cooperating inner surface of the seat ring is frustoconical;

d) the mutual positions of the seat ring and the rotary valve are chosen so that the frustoconical Inner surface and the spherical segment-shaped contact surface are tangential to each other in the closed position.

The inventive design of the rotary flap valve results in an excellent seal between the rotary valve and the seat ring without the material of the seat ring flowing occurs. This allows the advantageous properties of polytetrafluoroethylene over long periods of time be fully exploited.

Embodiments of the invention are shown in the drawing. Show in it:

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ORIGINAL INSPECTED

2065707

Pig. 1 passing through the axis of rotation of the rotary flap Diametrical section of a butterfly valve in the closed position,

Pig. 2 shows a diametrical section along the line II-II of Pig. 1 in the open position on a smaller scale,

Pig. 3 a sectional partial view of the seat ring and £ the rotary flap in the closed position in larger

Scale, .-..."

Pig. 4 is a radially sectioned partial view of another type of installation of the seat ring of the rotary valve,

Pig. 5 and 6 partial views of a further type of installation of the Seal in a radial section or in plan view,

Pig. Figure 7 is a partial view of a variant embodiment of the Pig design. 5 and 6,

W Pig. 8 a passing through the axis of rotation of the rotary flap

Diametral offset of the part of the ring body carrying the seat ring and of the adjacent retaining ring on a large scale and

Pig. 9 shows a further development of the arrangement of Pig. 8 on a larger scale.

809823/0 3 * 9 3SP

ORIGINAL INSPECTED

That in Pig. 1 to 3 shown rotary flap valve 1 is Installed between the puddles 2 of a pipeline 3. It consists of an annular body 4 with a between the two sections of the pipeline 3 lying cylindrical passage 5 and a rotary valve 6, which in axle journals and 8 is rotatably mounted in the ring body 4. The rotary flap is offset laterally with respect to the axis of rotation of the journal 7 and 8.

The ring body 4 has two parallel end faces 9 which lie opposite the pipeline flanges 2, and it is clamped between the pipeline flanges by tension screws, not shown, passing through holes 11 of the planes.

On each end face 9 there is an outwardly projecting sealing ring 12 made of polytetrafluoroethylene, which is arranged in a groove 13 for sealing between the ring body 4 and the pipe flanges 2 attached.

A concentric to the passage 5 seat ring 14 is between a shoulder 15 of the ring body 4 and a retaining ring fastened to the ring body 4 by countersunk screws 17 arranged. The seat ring 14 protrudes slightly into the interior of the passage 5, namely on the order of 1 to 2 mm. The opening of the seat ring 14 has a frustoconical surface.

The seat ring 14 is made of a material based on polytetrafluoroethylene, for example, from pure PoIytetrafluoräthylen or from a mixture of polytetrafluoroethylene and ground glass fibers, wherein the proportion of added glass fibers between 12 ° / o and 18 $ varies what an inert for aggressive reagents " for high temperatures (about 280 ⁰ C) suitable material corresponds.

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ORIGINAL INSPECTED

An operating handle (not shown) is screwed onto the threaded end 27 of the journal 7. The axle journal is connected to the rotary flap 6 by means of a square drive 28, which engages in a ring 29 attached to the rotary flap, rotatably connected.

The rotary flap 6 is thickened in its central portion so that it can withstand the pressure of the fluid. she consists preferably made of stainless steel or another corrosion-resistant metal. She has one about her girth annular convex contact surface 32, which in the closed position rests against the frustoconical inner surface of the seat ring 14.

The convex annular contact surface 32 is through a Section of a sphere S formed, the center of which is at the intersection 0 of the axis of the passage 5 and the The axis of rotation of the rotary flap 6 is located.

The mutual positions of the seat ring 14 and the contact surface 32 are chosen so that the frustoconical The surface of the seat ring 14 and the contact surface 32 are tangential to one another in the closed position (Pig. 3).

The rotary flap valve described works as follows:

When the rotary flap 6 is initially in the open position (Pig. 2), and the fluid in the Direction of arrow G flows, the operating handle is rotated in the direction of arrow P to close the valve, whereby the rotary flap 6 driven by the Yierkant 28 in the Pig. 2 position shown in phantom comes that of the closed position of Pig. 1 corresponds. It is stopped by a stop, not shown.

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The spherical contact surface 32, the center of which is on the intersection point O of the axis of the passage 5 and the axis of rotation the rotary flap 6 is, describes a to the frustoconical surface during the rotation of the rotary flap 6 of the seat ring 14 tangential ball.

During the rotation of the rotary flap 6, the contact surface 32 remains the same over its entire circumference or part of it in tangential contact with the frustoconical Surface of the seat ring 14 so that complete closure is obtained without difficulty.

In the closed position, the pressure of the fluid acting in the direction of the arrow G seeks the seat ring 14 in Bend in the direction of the large diameter portion of the contact surface 32, thereby strengthening the seal will. Therefore, if the seat ring 14 made of polytetrafluoroethylene exists, it shows no tendency to pleat at high pressure. There If it protrudes only impure or two millimeters, there is no danger that it will pass through a significant annular surface is pushed back.

The incorporation of ground glass fibers, which retain an elongated structure after grinding, has the surprising effect, the expansion coefficient of the To reduce mixtures significantly, and by order of magnitude by two thirds. The seat ring 14 consisting of this mixture therefore has a remarkable resistance to the flow, especially at high temperatures and high pressures. It also has good resilience against fluids with abrasive effects.

In practice, very good results are obtained, though the angle of inclination a (Pig. 3) of the frustoconical surface of the seat ring. 14 (i.e. half the cone angle) is between 6 ° and 10 ° and is preferably 8 °.

609823/0363

ORIGINAL INSPECTED

If the closing takes place under significant pressures during operation, practice shows that in the embodiment described the torque acting in the closing direction is insignificant until almost the closing position is reached. When opening, the torque near the lift-off is large, whereupon it very quickly becomes insignificant.

At low pressures, the seal remains satisfactory when the fluid is in the opposite direction to arrow G- Direction flows.

In another embodiment (Fig. 4) the seat ring 14 protruding into the interior of the channel is in a groove of the ring body 4 let in, which has practically the same width as the seat ring. The installation is done by deformation of the seat ring 14.

Experience shows that with common operating pressures and mean valve diameters (of the order of 10 cm) the seat ring 14 thus embedded in the groove 50 holds very well.

This simplifies the installation of the seat ring 14. The cost price of the valve is determined by the port case of the ring 16 and the screws 17 of the embodiment of FIG. 1 lowered considerably.

In another embodiment (Pig. 5 and 6) the seat ring 14 is inserted into a groove 51 of the annular body 4, the Width is greater than that of the seat ring. The seat ring 14 is inserted into the groove 51 by deformation.

A rigid ring 52, the width of which corresponds to the remaining space in the groove 51, is also in the Groove 51 inserted so that the seat ring 14 is held in its recess when the ring 52 is inserted is.

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2 O 6 ^ί: / .; 7th

To enable installation, the ring 52 is divided into at least two segments 52a, 52b. These will be with their Ends adjacent to one another inserted into the groove 51, whereby the ring 52 is restored after installation.

The mutual pressing of the segments 52a, 52b and the seat ring 14 in the groove 51 holds the segments with their Ends together without them looking to leave their position, the seat ring 14 in turn being held.

This development, like the previous one, facilitates the installation of the seat ring 14 and leads to a lower cost price des Yentils 1. The seat ring H can be easily inserted into the groove 51, the width of the same enables the deformation required to be reduced.

According to a further development of the embodiment of Pig. 5 and 6 are the segments of the ring 52 after installation in the groove 51 is fastened to one another by at least one weld seam, which two of them are in contact with one another The ends are firmly connected to one another and, for example, runs along the line of contact 53.

There is then no risk of the segments leaving the groove and the seat ring 14 is effectively held in this.

In another embodiment (FIG. 7) is in the mutually contacting ends of the two segments 52a, 52b Internal thread 54 formed into which a screw 55 is screwed, the diameter of which is chosen so that it seeks to spread the two ends of the segments 52a, 52b apart and so the possible play between all segments catching up.

6 0 9 8 2 3/0363 _0R , _Q , _{NAL 1NSPECTED}

This ensures that the segments cannot leave the groove 51 and that the seat ring 14 cannot can jump out of it.

In the execution of Pig. 8 one recognizes one Part of the ring body 4 of the Pig. 1 shown rotary flap valve, which has a recess 150, welehe a shoulder 15 forms on which the seat ring 14 for the spherical contact surface 32 of the rotary valve 6 is supported.

The recess 150 is followed by a recess 153, which extends over part of the recess 2 facing End face 9 of the ring body 4 extends. The retaining ring is in a corresponding manner with one in the recess 153 covenant 154 provided. The fastening of the cranked formed by the retaining ring 16 and the collar 153 Partly as in Pig. 1 by screws 17. This installation can be done very easily and quickly. This design also enables the seat ring 14 to be replaced very easily.

According to Pig. 9, the shoulder 15 has ribs 151 facing the seat ring 14. In a complementary manner the contact surface 16a of the retaining ring 16 has at least one rib 152 also facing the seat ring 14. The ribs 151 and 152 are preferably prismatic and each have a sharp edge which presses into the seat ring 14. Furthermore, the ribs 151 and 152 are preferably offset from one another.

When the retaining ring 16 is then pressed against the shoulder 15, it presses the seat ring 14 together. The ribs 151 » 152 deform this elastically, as a result of which concentric sealing zones are achieved.

609823/0363

In all cases, "when the rotary flap valve is actuated" is set found that the pressure between the conical seat ring and the spherical contact surface of the rotary valve is very high is low. Nevertheless, the valve remains tight under very high pressures. So can a valve with a diameter of 50 mm withstand a pressure of the order of 40 kg / cm without a leak, with the rotary flap remaining very mobile, which represents a surprising result.

609823/0363

Claims (10)

Claims (1J butterfly valve for pipes with an between two pipe flanges to be clamped ring body, the has a substantially rotationally symmetrical passage for the flow medium, one rotatable in the ring body mounted rotary flap, which is offset from its axis of rotation, which intersects the axis of the passage perpendicularly, and with one of the inner wall of the ring body slightly protruding into the passage seat ring, which is in the Closed position cooperates with a contact surface extending around the circumference of the rotary flap, characterized by combining the following features: a) the contact surface (32) of the rotary flap (6) is formed by a section of a ball (S), the center of which (O) lies on the intersection of the axis of the passage (5) and the axis of rotation of the rotary flap (6); b) the seat ring (14) consists of a material based on polytetrafluoroethylene and is in an annular shape Recessed groove of the ring body (4); c) in the closed position with the contact surface (32) of the rotary flap (6) cooperating inner surface of the Seat ring (14) is frustoconical; d) the mutual positions of the seat ring (14) and the rotary valve (6) are chosen so that the frustoconical Inner surface and the spherical segment-shaped contact surface (32) are tangential to one another in the closed position. £ 09823/03 ^ -3 ^ 206 = ^r 7: J7 2. Rotary flap valve according to claim 1, characterized in that that the seat ring (14) consists of a mixture of polytetrafluoroethylene and glass fibers. 3. Rotary flap valve according to claim 2, characterized in that the content of glass fibers is between 12 fo and 18 fo , 4. Rotary flap valve according to claim 1, characterized in that the seat ring (14) is made of additives Polytetrafluoroethylene consists. 5. Rotary flap valve according to one of the preceding claims, characterized in that the seat ring (14) receiving Groove through the shoulder (15) of a recess (150) made in the ring body (4) and the end face of an in the recess used retaining ring (16) is formed. 6. Rotary flap valve according to one of claims 1 to 4> characterized in that the groove (50, 51) in the inner surface of the Annular body (4) is incised. 7. Rotary flap valve according to claim 6, characterized in that the width of the groove (50) is equal to the width of the seat ring (14) is. 8. Rotary flap valve according to claim 6, characterized in that the width of the groove (51) is greater than the width of the seat ring is, and that the seat ring (14) in. The groove (51) is held by a ring (52) whose width corresponds to that in the Groove (51) corresponds to the remaining space and that for its installation in the groove (51) in at least two segments (52a, 52b) is divided. ORIGINAL INSPECTED 609823/0383 206S787 9. Rotary flap valve according to claim 8, characterized in that that at least two mutually contacting ends of the segments (52a, 52b) of the ring (52) after installation in the groove (51) are connected by a weld seam (53). 10. Rotary flap valve according to claim 8, characterized in that that between at least two segments (52a, 52b) of the ring (52) in contact with one another is a screw (55) is screwed into a threaded hole (54), half of which are in contact with one another Ends of the segments is formed. 609823/0363 Αϊ Blank page