Valve disk

The disclosure relates to a valve disk for a shutoff valve.

Shutoff valves are widely used shutoff devices for water economy. In contrast to sluice gates, valves are very compact and, for nominal widths greater than DN 300, require much less installation space. Pipeline systems with nominal widths from about DN 300 are, therefore, generally equipped with shutoff valves. The drawback of shutoff valves is that the valve disk, mounted to rotate within a housing, is situated directly in the flow. Since the valve disk must withstand the pressure difference of the system in the closed position, the valve disks are designed correspondingly thick, especially for high pressure differences. However, the thicker the valve disk is dimensioned, the more flow resistance it creates relative to the medium.

In previously known valve disks with two opposite hubs, there is the additional problem that the hubs present in the flow can generate a wake space, depending on the shape and width of the hubs, which causes eddies in the flow region on the outflow side. On the one hand, these eddies can increase the wake space and, therefore, increase the total resistance of the shutoff valve and, on the other hand, form eddy fields, which lead to excitation of vibration of the shutoff valve or the downstream pipeline.

Certain embodiments of the disclosure devise a valve disk of the type just mentioned, which permits improved flow and a reduction of turbulence on the outflow side.

Expedient embodiments and advantageous modifications of the such a valve disk are also disclosed.

According to the disclosure, arc-like recesses running along an inside surface of the two hubs are provided in the valve disk on the front of the disk-like valve body provided with two protruding hubs, in order to deflect the flow around the hubs. Eddy formation behind the hubs can be reduced on this account.

The recesses running along the hubs are expediently separated from each other by a center ridge. Indentations arranged in the center ridge between the recesses and running from the edge to the center of the valve body can be provided for further flow optimization and for weight reduction. The recesses and the preferably V-shaped indentations are expediently arranged so that, in a top view, the valve body has an X-shaped contour on the front between the two hubs. This contour contributes to flow optimization and also to stiffening.

The back of the valve body in a further advantageous embodiment is also contoured and has bent ribs. The ribs preferably lie opposite the recesses on the front and permit high rigidity with simultaneous weight saving in conjunction with the contour provided on the front of the valve body. If strength requires a change here, the ribs can also be displaced inward or outward relative to the recesses.

The hubs are advantageously designed to be streamlined and can have convex inside surfaces facing each other. In a particularly favorable variant with respect to flow, the hubs can have an elliptical or biconvex cross section and can also contain convex outer surfaces in addition to the convex inside surfaces facing each other.

In another expedient manner, passages can be arranged running through the hubs. Because of these passages on both hubs, pressure compensation between the center of the valve disk and the wake space behind the hubs can be achieved, and a partial vacuum and eddy formation on the outflow side of the valve disk can, therefore, be reduced. The activation moments for opening and closing the valve disk can also be reduced, and the hazard of vibrations of the shutoff valve and the downstream pipeline can be lessened.

With particular advantage, the passages can run from the inside of the valve disk through the hubs to the outside of the valve disk. Part of the flow can be directed toward the outside of the valve to reduce eddy formation. The passages can be aligned in parallel, at right angles, or at a different angle to the axis of rotation of the shutoff device and, therefore, arranged across the main direction of flow or at an angle to it. When several passages are present in each hub, the passages can be aligned differently or identically.

The passages can be expediently designed in the form of holes or slits. However, they can also have another appropriate shapes.

Additional details and advantages of the disclosure are apparent from the following description and preferred practical examples with reference to the drawing. In the drawing:

FIG. 1 shows a valve disk of a shutoff fitting in a top view;

FIG. 2 shows the valve disk of FIG. 1 in a side view;

FIG. 3 shows a valve body of the valve disk depicted in FIG. 1 in a bottom view;

FIG. 4 shows the valve body of the valve disk depicted in FIG. 1 in cross section along the axis of rotation;

FIG. 5 shows the valve body of the valve disk depicted in FIG. 1 in a perspective view; and,

FIG. 6 shows the valve disk of FIG. 1 in a section at right angles to the axis of rotation.

A valve disk 1 of a shutoff fitting is shown in FIGS. 1 and 2 in a top view and side view. The depicted valve disk 1 contains a disk-like valve body 2 , which has two outside hubs 4 opposite each other and protruding relative to the front 3 of the valve body 2 . The valve disk 1 also includes an annular or disk-like seal 5 , apparent in FIG. 2 , and a securing ring 8 releasably fastened to the back 6 of valve body 2 by means of screws 7 , through which the seal 5 is fastened to the valve body 2 . The valve body 2 of the valve disk 1 is mounted to pivot around an axis of rotation 9 running perpendicular to the center axis of the passage opening in known fashion within a housing provided with a round passage opening.

As follows from FIG. 1 , the valve body 2 on a front 3 arranged between hubs 4 has a contour further described below to deflect the flow around the hubs 4 . A special contour for flow deflection and stiffening is also provided on the back 6 of the valve body 2 depicted in FIG. 3 .

It is apparent in FIGS. 1 and 5 that the hubs 4 protruding relative to the front 3 of the valve body 2 have convex inside surfaces 10 facing each other. In the depicted embodiment, the hubs 4 have an elliptical or biconvex cross section and also contain convex outer surfaces 11 in addition to the convex inner surfaces 10 facing each other. A side opening 12 to accommodate a bearing pin (apparent in FIG. 4 ) is provided in the two hubs 4 .

In addition to openings 12 , the hubs 4 have passages 13 running through them. Via the passages 13 in the two hubs 4 , part of the fluid flowing along them in the open position of the valve disk 1 can be guided to the outside of the valve and pressure compensation achieved on this account between the center of the valve disk 1 and the wake space behind hubs 4 . In this way, partial vacuum and eddy formation on the outflow side of valve disk 1 can be reduced. In addition, the activation moments for opening and closing valve disk 1 can be reduced, and the hazard of vibrations of the valve disk 1 and the downstream pipeline can be lessened.

In the depicted embodiment, the passages 13 are holes, which run obliquely to the axis of rotation 9 . The passages 13 , however, can also be slits and run parallel or perpendicular to the axis of rotation 9 . The passages 13 can also have the same cross section or different cross sections, and be aligned identically or differently.

It is readily apparent from FIG. 5 that two arc-like recesses 14 running along the two inside surfaces 10 of hubs 4 are arranged on the front 3 of the valve body 2 in order to deflect the flow around the hubs 4 . The two groove-like recesses 14 with U-shaped cross sections are separated from each other by a convexly arched center ridge 15 that widens on both sides to the outside from the center of valve body 2 . Because of the two arc-like recesses 14 flow channels are formed between the two hubs 4 , through which the flow is diverted around the hubs 4 . Two diametrically opposite V-shaped (in a top view) indentations 16 are provided in the center ridge 15 , which run from the edge to the center of the valve body 2 . Because of this, the valve body 2 has an X-shaped contour in the top view on the front between the two hubs 4 . This contour contributes to flow optimization and also to stiffening.

On the back 6 , shown in FIG. 3 , the valve body 2 also has a special contour with bent ribs 17 , a depression 18 arranged between the ribs 17 , and depressions 19 on the back arranged between the ribs 17 and the outside of the valve body 2 . The ribs 17 lie opposite the recesses 14 on the front 3 , whereas the depression 18 is opposite the center ridge 15 arranged on the front. The depression 18 has a width that increases from the center to both sides. Because of this, the valve body 2 contains a W-shaped cross-sectional surface, recognizable in FIG. 4 , in a cross section running along its axis of rotation 9 through the two hubs 4 . An annular recess 20 is also provided on the back of the valve body 2 to accommodate the seal 5 and the securing ring 8 .

It is apparent in FIG. 6 that the arc-like recesses 14 running along both inside surfaces 10 of hubs 4 have a depth that increases from the two edges of the valve body 2 toward the center. The depth of the recesses 14 increases from the edges of the valve body 2 to the hub. The recesses 14 have the greatest depth in the center of hub 4 .