EP4396478A1 - Valve gate for a slide valve - Google Patents

Abstract

The present disclosure relates to slide valves, in particular to a valve gate. The present disclosure relates to a valve gate for a slide valve comprising a ductile cast iron core (4) having two lateral protrusions (4A), said core being coated with a first polymer material (3) and two guides (1) made of a second polymer material, each fitted over a respective coated lateral protrusion, for sliding in grooves of the valve as the gate slides between an open position and a closed position of the valve; wherein the second polymer material is harder than the first polymer material.

Description

D E S C R I P T I O N

VALVE GATE FOR A SLIDE VALVE

FIELD OF INVENTION

[0001] The invention belongs to the field of slide valves, in particular to a valve gate. In particular, slide valves to be used in pipeline system for distributing and /or handling fluid such as water, sew-ages, natural gas or similar liquid or gaseous media.

BACKGROUND

[0002] Document EP2935955 discloses a valve wedge for a slide valve comprising a rough cast metal wedge for a slide valve comprising a rough cast metal wedge core encapsulated in, i.e. coated with, a soft seal encapsulation, i.e. a soft coating, and having two guide members projecting transversely in opposite directions and being adapted to engage respective one of guide grooves provided inside a housing of the slide valve so as to take up an axial pressure exerted on the valve wedge during operation, each of said guide members comprising a sideways projecting rib of said rough cast wedge core and a prefabricated wear and corrosion-resistant slide shoe arranged thereon, each rib comprising laterally opposite lateral surfaces and an endface and each shoe comprising two opposite lateral walls with inner surfaces and outer surfaces adapted for interacting with corresponding slide surfaces of the guide grooves and each shoe being fixedly connected with or vulcanized to the respective one of the ribs by means of soft seal encapsulation present between the rough cast wedge core and the shoe.

[0003] Document EPO171693 discloses a slide valve with a valve wedge comprising guide shoes that are attached to the valve wedge core and moulded together with a rubber encapsulation of the valve wedge. [0004] These facts are disclosed in order to illustrate the technical problem addressed by the present disclosure.

[0005] The valve gate of the present disclosure is to overcome at least some of the abovementioned drawbacks and especially to provide a valve with better sliding properties and proteted against corrosion .

GENERAL DESCRIPTION

[0006] The present description relates to a valve gate for a slide valve. Slide valves may be used in pipeline system for distributing and /or handling fluid such as water, sewages, natural gas or similar liquid or gaseous media. A slide valve comprises a housing defining a passage way for the fluid to flow in an axial direction to the housing. The passage may be closed and open by sliding the valve wedge in a direction transverse to the axial direction.

[0007] The present description relates to the technical field of slide valves and in particular to a valve gate comprising a cast iron core coated with a first polymer material and having two guide structure members projecting transversely in opposite directions to engage in the respective guide grooves provided by the slide valve. This guide members controls de slide wedge movement sliding into the guide grove and support the axial force of the operation.

[0008] The referred guide comprising an external face and an internal face with ribs that maintains a space between the guide and guide structure to be filled during the core coating process with a first polymer material, preferable a vulcanized rubber, these ribs are protrusions in the internal face, furthermore the guides has a rim in their ends that accompanies the curvature of the iron core which is covered and blocked by the rubber coating helping the fixation of the guide with the guide structure member. This fixation of the rim and the first polymer material that fills the interior of the guide ensures a strong fixation prevent the deformation and the detachment of the guide. The external face is smooth to facility de sliding of the wedge. The guide is made of a second polymer material that can be polyamide or polyoxymethylene (POM). Preferably the polyamide selected is PA6.6 . However, other plastic materials may be used having good sliding properties, high wear resistance and heat resistance. Preferably, the referred guides are formed by injecting molding.

[0009] Typically, the material of the core is cast iron which may undergo oxidation when exposed. Therefore, a vulcanized rubber coating is provided to protect the core against the corrosion.

[0010] In an embodiment, the first polymer material coating is applied around the iron core with a specific thickness by mold injection. The thickness has to be enough to cover and block the rim of the guide.

[0011] The material of the coating can be ethylene propylene diene monomer (EPDM) for fluid and nitrile butadiene (NBR) for gases. However, other properties may also be used.

[0012] The present disclosure relates to a valve gate for a slide valve comprising: a ductile cast iron core having two lateral protrusions, said core being coated with a first polymer material, and two guides made of a second polymer material, each fitted over a respective coated lateral protrusion, for sliding in grooves of the valve as the gate slides between an open position and a closed position of the valve; wherein the second polymer material is harder than the first polymer material.

[0013] In an embodiment, the guides are arranged symmetrically opposite in respect of the ductile cast iron core.

[0014] In an embodiment, the guides comprises a U-shaped cross-section defining an internal face and an external face.

[0015] In an embodiment, the internal face of the guide comprises a plurality of ribs for contacting with the protrusions defining a cavity to be filled with first polymer material as the core is coated with the first polymer material.

[0016] In an embodiment, the guide has a rim leaving a gap between said guide and the core for the first polymer material to enter into the cavity through said gap. [0017] In an embodiment, the internal face of the guide comprises the plurality of ribs distributed around the internal face of the guide such that the guide is supported against the protrusion by said ribs.

[0018] In an embodiment, the plurality of ribs are distributed to support the guide around the protrusion.

[0019] In an embodiment, the first polymer material is vulcanized rubber.

[0020] In an embodiment, the second polymer material is a rigid plastic.

[0021] In an embodiment, the guides are fixed to the protrusions of the iron core by the first polymer material.

[0022] In an embodiment, the valve gate has a hollow for receiving valve gate actuation means.

[0023] In an embodiment, the hollow is also coated by the first polymer material.

[0024] In an embodiment, a threaded part fitted into said hollow for coupling with valve gate actuation means.

[0025] In an embodiment, the guide is made of a polymer selected from polyamide or polyoxymethylene., or mixtures thereof.

[0026] In an embodiment, the guide is made of polyamide PA6.6.

BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The following figures provide preferred embodiments for illustrating the description and should not be seen as limiting the scope of invention.

[0028] Figure 1: illustrates one embodiment of a valve guide (1) that comprises a rib (1A), a rim (IB) and a cavity (1C).

[0029] Fig.2: illustrates one embodiment of a front view of the valve gate (2) that comprises a guide (1). [0030] Fig.3: illustrates one embodiment of a side view of the valve gate (2) that comprises a guide (1).

[0031] Fig.4: illustrates one embodiment of a top view of the valve gate (2) that comprises a guide (1).

[0032] Fig.5: illustrates one embodiment of a cut view B-B of the valve gate (2) that comprises a guide (1) , a rib (1A), a rim (IB), a cavity (1C), first polymer material (3), a ductle cast iron core (4) and lateral protrusion (4A).

[0033] Fig.6: illustrates one embodiment of a cut view C-C of the valve gate (2) that comprises a guide (1) , a rib (1A), a rim (IB), a cavity (1C), first polymer material (3), a ductle cast iron core (4) and lateral protrusion (4A).

[0034] Fig.7: illustrates one embodiment of an exploded view of the valve gate (2) that comprises a guide (1) , first polymer material (3), a ductle cast iron core (4), lateral protrusion (4A).

[0035] Fig.8: illustrates one embodiment of a valve gate (2) that comprises a guide (1).

[0036] Fig.9: illustrates one embodiment of a slide gate (5) and valve gate (2) thereof.

DETAILED DESCRIPTION

[0037] The present invention relates a valve gate (2) with a ductile cast iron core (4) which is entirely coated with a first polymer material, preferable injected and vulcanized rubber (3). The first polymer material «ensures the fixation of the guides (1) with ductile cast iron core (4). Theseguides (1) are fit in a vertical rail that block the axial movement and allows the vertical movement of the gate.

[0038] In an embodiment, the guide (1) is made to fit in the lateral protrusion (4A) and contains within it ribs (1A) that allows some cavities (1C) between the guide (1) and the protrusion (4A) for receive the first polymer material, preferably injected and vulcanized rubber (3) which after solidifying ensures the adhesion of the guide (1) with the iron core (4). Furthermore the guide (1) has a rim (IB) in their ends that is spiked in the first polymer material (3) which helps to fasten the guide (1) with the gate (2).

[0039] In an embodiment, Fig. 1 represents the guide (1) in several perspectives. The the guide (1) has a U-shaped cross-section that defines an internal face and an external face. The internal face of the guide (1) comprises a plurality of ribs (1A) distributed around the internal face for contacting with the protrusions (4A). The ribs (1A) define cavities (1C) to be filled with a first polymer material as the core is coated with the first polymer material. The guide 81) also comprises a rim (IB), leaving a gap between the guide (1) and the core (4) for the first polymer material to enter into the cavity (1C) through the gap.

[0040] In an embodiment the guide (1) is made of a second polymer material which is harder than the first polymer material.

[0041] In an embodiment, the first polymer material is vulcanized rubber and the second polymer material is a rigid plastic, preferably polyamide or polyoxymethylene.

[0042] In an embodiment, Fig.2 represents each of the two guides (1) that are fitted in each of the two lateral protrusions (4A) of the valve gate (2). The guides are symmetrically opposite in respect of the ductile cast iron core (4).

[0043] In an embodiment, Fig. 3 is a side view of the valve gate (2) that comprises the guide (1).

[0044] In an embodiment, Fig. 4 is a top view of the valve gate (2) comprising the guides (1). The valve gate (2) also comprises a hollow for receiving valve gate actuation means.

[0045] In an embodiment, Fig. 5 is a cut view B-B of the valve gate (2) comprising the ductile cast iron core (4), coated by the first polymeric material (3), preferably the vulcanized rubber. The cavities (1C) present in the guide (1) are filled with the vulvanized rubber. The plurality of ribs (1A) are distributed around the internal face of the guide (1) such that the guide is supported against the protrusion by the ribs. Preferably, the plurality of ribs (1A) are distributed to support the guide around the protrusion.

[0046] In an embodiment, Fig. 6 is a cut view C-C of the valve gate (2), comprising the ductile cast iron core (4), coated by the first polymeric material (3). The cavity (1C) was filled with first polymer material as the core was coated with the first polymer material. The plurality of ribs (1A) are distributed around the internal face of the guide (1).

[0047] In an embodiment, Fig. 7 is an exploded view of the valve gate (2) that comprises the guide (1), the lateral protrusions (4A), the ductile cast iron core (4) and the first polymer material (3). The hollow is also coated by the first polymer material and a threaded part is fitted into the hollow for coupling with valve gate actuation means.

[0048] In an embodiment, Fig.8 illustrates the valve gate (2) that comprises the guide (1) and the ductile caste iron core (4) coated with the first polymer material.

[0049] In an embodiment, Fig. 9 illustrates the slide gate (5) and valve gate (2) thereof.

[0050] The disclosure should not be seen in any way restricted to the embodiments described and a person with ordinary skill in the art will foresee many possibilities to modifications thereof. The above described embodiments are combinable. The following claims further set out particular embodiments of the disclosure.

Claims

8

C L A I M S Valve gate (2) for a slide valve (5) comprising: a ductile cast iron core (4) having two lateral protrusions (4A), said core being coated with a first polymer material (3), and two guides (1) made of a second polymer material, each fitted over a respective coated lateral protrusion (4A), for sliding in grooves of the valve (5) as the gate (2) slides between an open position and a closed position of the valve (5); wherein the second polymer material is harder than the first polymer material. Valve gate according to the previous claim wherein the guides (1) are arranged symmetrically opposite in respect of the ductile cast iron core (4). Valve gate (2) according to any of the previous claims, wherein the guides (1) comprises a U-shaped cross-section defining an internal face and an external face. Valve gate according to previous claim wherein the internal face of the guide (1) comprises a plurality of ribs (1A) for contacting with the protrusions (4A) defining a cavity (1C) to be filled with first polymer material as the core is coated with the first polymer material. Valve gate according to the previous claim wherein the guide (1) has a rim (IB) leaving a gap between said guide (1) and the core (4) for the first polymer material to enter into the cavity (1C) through said gap. Valve gate according to claim 4 or 5 wherein the internal face of the guide (1) comprises the plurality of ribs (1A) distributed around the internal face of the guide (1) such that the guide is supported against the protrusion by said ribs. Valve gate according to the previous claim wherein the plurality of ribs (1A) are distributed to support the guide around the protrusion. 9 Valve gate according to any of the previous claims wherein the first polymer material is vulcanized rubber. Valve gate according to any of the previous claims wherein the second polymer material is a rigid plastic. Valve gate according to any of the previous claims wherein the guides (1) are fixed to the protrusions (4A) of the iron core by the first polymer material. Valve gate according to any of the claims wherein the valve gate (2) has a hollow for receiving valve gate actuation means. Valve gate according to the previous claim wherein the hollow is also coated by the first polymer material. Valve gate according to the claim 11 or 12 comprising a threaded part fitted into said hollow for coupling with valve gate actuation means. The valve gate according to any of the previous claim previous claim wherein the guide (1) is made of a polymer selected from polyamide or polyoxymethylene. The valve gate according to the previous claim wherein the guide (1) is made of polyamide PA6.6.