EP3247927A1

EP3247927A1 - Wedge-gate valve

Info

Publication number: EP3247927A1
Application number: EP16703862.9A
Authority: EP
Inventors: Wojciech KRAWCZYK
Original assignee: Zetkama R&d Sp ZOO
Current assignee: Zetkama R&d Sp ZOO
Priority date: 2015-01-22
Filing date: 2016-01-12
Publication date: 2017-11-29
Also published as: PL226326B1; WO2016118024A1; EA033365B1; EA201791559A1; PL411031A1

Abstract

The valve, according to the invention, has a body (1) with an inlet port (2) and an outlet port (3), a-socket (4) provided in the body (1) with surfaces of which the wedge (5) cooperates, a closing cover (7) connected to the body (1), in which a spindle (6) is mounted sealed with a gland (8). At the outer side the spindle (6) is controlled in a rotational manner, and at the opposite side it is connected to the wedge (5). The socket (4) of the body (1) is provided with a front slot (11') and a rear slot (12'), and the wedge (5) is provided with a front rib (11) and a rear rib (12) made of elastic material, wherein the front rib (11) cooperates with the front slot (I I') of the socket (4) of the body (1), and the rear rib (12) cooperates with the rear slot (12') of the socket (4) of the body (1).

Description

Wedge-gate valve

The object of the invention is a wedge-gate vaive with a body, having an inlet and an outlet with a flow zone between them, with a sealing wedge in the flow zone and with a sliding element cooperating with the contact surface of the wedge in a closed state.

Wedge gates with a soft seal of the wedge are used in water installations, industrial installations, sewage and gas installations. They function as a cut-off, i.e. they should operate in fully closed or fully open positions.

A gate valve with a soft seal of the wedge is known, consisting of a frame closed with a cover, with a socket of which a suitably shaped wedge cooperates, said wedge sliding along a spindle through a trapezoidal thread located at its end and in the wedge assembly. The spindle is mounted and sealed in the cover by means of a gland, and has a suitably shaped end which protrudes beyond the cover on which a controlling wheel or a gate controlling drive unit is put on. Rotation of the spindle performed by means of the wheel or the gate controlling drive unit causes sliding of the wedge assembly which is protected by guides against rotation located in the frame. The gate is closed by pressing the wedge assembly with the spindle against the surface of the socket located inside the frame. Known wedge gates with a soft seal are provided with a wedge assembly which constitutes a wedge and a threaded element formed as a metal forging or casting. Most commonly, the wedge is made of cast iron covered with rubber, and the threaded element is made of brass.

From patent specification US 2,934,313, a gate valve is known which has a four-part housing with a lower part of the housing to which a housing cover is mounted by means of screws. The lower part of the housing and the housing cover, facing each other with two sides form openings, each having a thread. A tubular body with a matching thread can be screwed into each of the two threads. All the four parts form a tube. The cross-section of the flow through this tube can be closed by means of a sliding element which can be lowered transversely from the housing cover relatively to the direction of the flow in the tube. For sealing the contact surface between the housing parts and the contact surface between the sliding element and the cover, the gate valve has a rubber sealing insert. The sealing insert has a cylindrical shape. Inside the sealing insert, the cross-section of the flow is substantially limited by means of metal rings, pushed into this insert. The metal rings serve to retain the undisturbed cross-section of the flow inside the sealing insert.

In patent specification US 5,279,320, a gate valve is shown with a sliding element which has a groove on each side. When opening and closing the gate valve, the sliding element is guided by means of grooves through appropriate tracks in the housing of the gate valve. The sliding element has a plastic coated core . In the groove zone, the core coating is made of hard polymer to reduce friction. In the other zones in which the sliding element in the closed state rests against the cover, the coating is made of soft polymer. This ensures a good seal.

In German patent application DE 43 25 192 Al, a disk gate valve is shown. In this case, it is possible to assembly and disassembly the valve in the direction of valve movement . For this purpose, the disk gate valve has a slidable housing, divided into an upper part and a lower part. A sealing element with a circular opening is built into the slidable housing. If it is necessary to replace the sealing element, the upper part of the housing can be removed from the lower part together with the sealing element. Then, the sealing element in the upper part of the housing can be replaced. Furthermore, the sealing element has a separate transverse sealing which can be individually separated from the rest of the sealing element when disassembling the disk gate valve.

From Polish patent specification PL202950, a gate valve construction is known in which the gate valve has a housing comprising a lower part and an upper part which are separated by a flange connection; a first side part comprising a housing inlet and a second side part comprising a housing outlet; clamp connections between said first side part and the lower and upper parts and between said second side part and the lower and upper parts, respectively; a sealing insert clamped between the lower part, the upper part and the first and second parts; and a sliding element adapted for sliding movement in the housing between a first position in which it establishes a barrier of the gate between the inlet and the outlet, and a second position in which the barrier of the gate is removed, wherein the sealing insert has an opening in front of said inlet and outlet, and furthermore, it has a contact surface adapted for sealingly contacting the sliding element when the sliding element is moved between the positions, and the sealing contact establishes a barrier of the gate when the sliding element is located in the first position. The gate valve according to the invention is characterised in that the sealing insert comprises a rigid body permanently connected to zones of lower rigidity than the rigid body, wherein the zones of lower rigidity include said contact surface and clamp zones of the flange connection and zones clamped between the first side part and the lower and upper parts and between the second side part and the lower and upper parts. During operation, for example in tap water installations, the gate valves must ensure reliable closing for a relatively long period of use (up to 50 years). Therefore, the known gate valves have relatively soft and simply shaped seals. These seals must be relatively tightly mounted in the housing or applied on individual elements as coatings. In this manner, deformation of the seals during operation, caused by liquid pressure which would destroy them or made them an obstacle to the free flow, is prevented. In the known gate valves having a cylindrical flow area, this is however a substantial limitation due to the housing parts or other support elements of a relatively strong material.

The wedge-gate valve, according to the invention, has a body with an inlet port and an outlet port, a socket provided in the body with surfaces of which a wedge cooperates, a closing cover connected to the body, in which a spindle is mounted sealed with a gland, wherein at the outer side, the spindle is controlled in a rotational manner, and at the opposite side, it is connected to the wedge. The socket of the body is provided with a front slot and a rear slot, and the wedge is provided with a front rib and a rear rib made of elastic material, wherein the front rib cooperates with the front slot of the body socket, and the rear rib cooperates with the rear slot of the body socket.

It is preferable when the wedge, in a plane perpendicular to the plane defined by the axes of symmetry of the front and rear ribs, is provided with a left recess and a right recess in which a left guide and a right guide are press- fitted, wherein the guides are made of a low friction coefficient material and they cooperate with a left projection and a right projection of the valve body.

It is also preferable when the front rib and the rear rib are made of rubber.

It is also preferable when the front rib and the rear rib are made of plastic. It is also preferable when the left guide and the right guide are made of rubber.

It is also preferable when the left guide and the right guide are made of plastic.

It is also preferable when in the wedge, a nut cooperating with the threaded spindle is mounted in the wedge.

It is preferable when the nut is made of brass.

It is also preferable when the wedge is made of cast iron and covered with rubber.

The object of the invention is shown in an embodiment, in the drawing in which Fig. 1 shows the wedge-gate valve in a longitudinal section; Fig. 2 shows a section through the valve along the line A-A of Fig. 1; Fig. 3 shows the wedge in a side view; Fig. 4 shows the wedge in a section along the line C-C of Fig. 3; Fig. 5 shows the wedge in a section along the line B-B of Fig. 3; and Fig. 6 shows the wedge in a perspective view.

As shown in Fig. 1 , the wedge-gate valve, according to the invention, has a body 1 with an inlet port 2 and an outlet port 3. The valve has a socket 4 provided in the body 1 with surfaces of which a wedge 5 cooperates, a closing cover 7 connected to the body 4, in which a spindle 6 is mounted sealed with a gland 8. At the outer side, the spindle 6 is controlled in a rotational manner, and at the opposite side, it is connected to the wedge 5. The wedge 5 is made of cast iron and covered from the outside with rubber.

The socket 4 of the body 1 is provided with a front slot 11 ' and a rear slot 12', and the wedge 5 is provided with a front rib 1 1 and a rear rib 12 made of elastic material, in this embodiment made of rubber, wherein the front rib 1 1 cooperates with the front slot 1 1 ' of the socket 4 of the body 1, and the rear rib 12 cooperates with the rear slot 12' of the socket 4 of the body 1. This means that during operation of the valve, that is, during closing or opening thereof, the front rib 11 is supported by the edge of the front slot 1 1 ' of the socket 4 of the body 1, and the rear rib 12 is supported by the edge of the rear slot 12' of the socket 4 of the body 1 so that thrust caused by the pressure of the liquid passing through the valve is appropriately transferred onto the body 1 of the valve. Also, in the course of flow of the medium through the valve in a fixed position of the wedge 5, between the positions of full opening and full closure, and also in these positions, the front rib 11 and the rear rib 12, due to their construction according to the invention, counteract vibrations of the wedge 5, which has a significant impact on the durability of the wedge 5 and of the whole wedge valve.

In an embodiment shown in Fig. 1, Fig. 2, Fig. 4 and in Fig. 5, the wedge is covered with rubber but it is obvious that in other embodiments it may be a different material with appropriate physicochemical properties, in particular, such as elasticity, ability to damp vibrations, resistance to chemical agents or the like. This material may be a suitable plastic material. At the same time, it is preferable when the front rib 11 and the rear rib 12 of the wedge 5 are made of the same material as the one covering the wedge 5.

The wedge 5 of the valve, in a plane perpendicular to the plane defined by the axes of symmetry of the front rib 11 and the rear rib 12, is provided with a left recess 13' and a right recess 14', as shown in the embodiment of the invention in Fig. 2 and in Fig. 4. The left recess 13' and the right recess 14', just like the whole wedge 5, are covered with rubber, and in these recesses 13' and 14', a left guide 13 provided in the left recess 13' and a right guide 14 provided in the right recess are additionally mounted. The two guides, the left one 13 and the right one 14, are press-fit in the recesses and are made of a low friction coefficient plastic . During operation of the valve, that is, during closing or opening thereof, the left guide 13 and the right guide 14 cause the left recess 13' and the right recess 14' to slide on a left projection 13" and a right projection 14" of the body 1 of the valve. This ensures smooth operation of the valve, and also, due to the low wear during operation, sufficiently high durability of the valve. Also, in the course of flow of the medium through the valve in a fixed position of the wedge 5, as mentioned, the valve of this type is expected to exhibit appropriately high durability which is estimated to last several decades of operation. inside the wedge 5, in an appropriate relief, a nut 10 is mounted made of brass. This is to provide a low friction when the nut 10 operates during opening or closing of the valve. The nut 10 has a shape designed so that during operation, having been mounted in the wedge 5, it cannot rotate. The threaded spindle 6 is screwed into the nut 10, , which is rotated in the cover 7 by means of a controlling wheel 9 mounted on the outside of the valve. The controlling wheel 9 can be actuated manually or through a remote-controlled mechanical actuator.

Claims

1. A wedge-gate valve having a body with an inlet port and an outlet port, a socket provided in the body with the surfaces of which a wedge cooperates, a closing cover connected to the body, in which a spindle is mounted sealed with a gland, wherein at the outer side the spindle is controlled in a rotational manner, and at the opposite side it is connected to the wedge, characterised in that the socket 4 of the body 1 is provided with a front slot 1 and a rear slot 12', and the wedge 5 is provided with a front rib 1 1 and a rear rib 12 made of an elastic material, wherein the front rib 1 1 cooperates with the front slot 1 Γ of the socket 4 of the body 1, and the rear rib 12 cooperates with the rear slot 12' of the socket 4 of the body 1.

2. The gate valve according to claim 1, characterised in that the wedge 5, in a plane perpendicular to the plane defined by the axes of symmetry of the front rib 1 1 and the rear rib 12, is provided with a left recess 13' and a right recess 14' in which a left guide 13 and a right guide 14 are press-fitted, wherein the guides 13 and 14 are made of a low friction coefficient material and they cooperate with a left projection 13" and a right projection 14" of the valve body 1.

3. The gate valve according to claim 1, characterised in that the front rib 1 1 and the rear rib 12 are made of rubber.

4. The gate valve according to claim 1, characterised in that the front rib 1 1 and the rear rib 12 are made of plastic.

5. The gate valve according to claim 1, characterised in that the left guide 13 and the right guide 14 are made of rubber.

6. The gate valve according to claim 1, characterised in that the left guide 13 and the right guide 14 are made of plastic.

7. The gate valve according to claim 1 , characterised in that a nut 10 cooperating with the threaded spindle 6 is mounted in the wedge 5,.

8. The gate valve according to claim 5, characterised in that the nut 10 is made of brass.

9. The gate valve according to claim 1, characterised in that the wedge 5 is made of cast iron and covered with rubber.