Piston valve comprising a sealing unit in the passage area of ​​a piston

Abstract

Piston valve comprising a piston sealing unit (2, 3, 4, 5, 6, 7) in the passage area of ​​a valve housing (1), characterized in that the piston sealing unit (2, 3, 4, 5, 6, 7) has a metallic pre-seal formed from the piston lower part (4) and the valve housing (1), a permanently elastic piston valve ring (2), in particular made of laminated graphite (8), with a splintered sheet insert (9), and a metallic secondary seal formed from the piston upper part (3) and the valve housing (1), wherein the piston valve ring (2) is axially arranged between the metallic pre-seal and the metallic secondary seal and is elastically deformed and resealed under contact pressure in order to ensure a multi-stage seal between the piston lower part (4), piston upper part (3), piston valve ring (2) and the valve housing (1).

Description

[0001] The invention relates to a piston valve comprising a sealing unit in the passage area of ​​a piston according to the preamble of claim 1.

[0002] The invention relates in particular to the sealing of piston valves in the field of valve technology, wherein the piston valves are operated under high thermal and mechanical loads. The invention further relates to a hybrid sealing device for the piston passage of a valve, comprising both metallic sealing elements and a permanently elastic sealing element made of laminated graphite with a splintered sheet metal insert.

[0003] Piston valves are frequently used in industrial applications such as power plants, refineries, or chemical plants, where high pressures and temperatures prevail. Sealing the valve between the moving piston and the housing presents a particular challenge.

[0004] Typically, metallic sealing systems or elastomeric seals are used. While metallic seals offer high temperature and pressure resistance, they have limited adaptability to tolerances and unevenness. Elastomeric seals, on the other hand, are deformable but are subject to thermal wear and chemical aging.

[0005] German patent application DE 10 2010 000 000 A1 discloses a combined sealing unit comprising metallic and elastic components. However, long-term sealing remains critical in high-temperature applications.

[0006] The object of the invention is therefore to provide a sealing unit for a piston valve which: • ensures a high sealing effect under changing temperatures and pressures, • permanently resistant to chemical and thermal influences, • possesses good resilience and • ensures an emergency seal in case of a partial failure.

[0007] The problem is solved with a piston valve comprising a sealing unit in the passage area of ​​a piston according to claim 1. Advantageous embodiments of the invention are features of the dependent claims.

[0008] The invention relates to a piston valve comprising a piston sealing unit in the passage area of ​​a valve housing. The sealing unit can also be referred to as a hybrid sealing unit.

[0009] The piston sealing unit according to the invention has a metallic pre-seal which is formed from the piston lower part and the housing.

[0010] Furthermore, the piston sealing unit according to the invention has a permanently elastic piston valve ring, in particular made of laminated graphite, with a, in particular metallic, spiky sheet metal insert.

[0011] Furthermore, the piston sealing unit comprises a metallic secondary seal, which is formed by the piston crown and the valve housing. The metallic secondary seal is preferably arranged between the piston crown and the valve housing.

[0012] According to the invention, the piston-valve ring is arranged axially between the metallic pre-seal and the metallic post-seal and is elastically deformed and re-sealed under contact pressure to ensure a multi-stage seal between the piston lower part, piston upper part, piston-valve ring and valve housing.

[0013] The advantages of the invention are: • High temperature and pressure resistance due to metallic sealing elements • Permanent sealing thanks to elastic graphite laminate • Chemical resistance to aggressive media • Mechanical stability through skewered sheet metal insert • Multi-level safety through combination of sealing elements

[0014] It can be particularly advantageous to provide that the skewer plate insert is made of stainless steel.

[0015] According to a further advantageous embodiment of the invention, the laminated expanded graphite of the piston valve ring can exhibit a springback of at least 10% of the compression.

[0016] The metallic pre-seal of the piston lower part can be convex and rest forcefully on a correspondingly conical sealing surface of the valve housing, thereby creating a self-centering metallic seal.

[0017] According to an advantageous embodiment of the invention, the metallic secondary seal of the piston top is designed to be convex and rests forcefully on a correspondingly conical sealing surface of the valve housing.

[0018] Further objectives, advantages, features, and applications of the present invention will become apparent from the following description of an exemplary embodiment with reference to the drawing. All features described and / or illustrated, individually or in any meaningful combination, constitute the subject matter of the present invention, even independently of their compilation in the claims or their cross-references.

[0019] Some of these show schematically: Fig. 1 a piston valve with a sealing unit in the passage area of ​​a piston in a sectional view, Fig. 2 a) a detailed view of section H of the in Fig. 1. a) the piston valve shown and b) an exploded view of the piston assembly including the connecting parts, Fig. 3 a) a detailed view of section H of the in Fig. 1. Piston valve shown in the “closed” position and detail of the metallic pre-seal in a sectional view, b) a further detail view of section H of the in Fig. 1. Piston valve shown in the “closed” position and detail of the metallic after-seal in a sectional view and c) a detail view of section H of the in Fig. 1. Piston valve shown in the "open" position in a sectional view, Fig. 4 a) a detailed view of the piston valve ring in a sectional view and b) a perspective image of the surface structure of the metallic spiking plate.

[0020] Identical or equivalent components are identified in the following figures of the drawing by reference numerals based on an embodiment, in order to improve readability.

[0021] The invention will now be explained in more detail using the preferred embodiments, without, however, limiting the scope of protection to them.

[0022] In Fig. Figure 1 shows a piston valve for use in the chemical, petrochemical, and plastics industries (aggressive media, high temperatures) and power plants (steam, condensate), which has a hybrid sealing unit (2, 3, 4, 5, 6, 7) in the area of ​​the piston passage of the valve housing (1). The sealing unit (2, 3, 4, 5, 6, 7) is axially divided into three zones: In the first zone, a metallic pre-seal is provided consisting of the piston base (4) and the valve housing (1). The sealing surface of the piston base (4) is convex, as shown in Fig. Section AB is visible in section 3.

[0023] The Fig. 3 shows a) a detailed view of section H of the in Fig. 1. the piston valve shown in the “closed” position and details of the metallic pre-seal in a sectional view, b) a further detailed view of section H of the in Fig. 1. the piston valve shown in the “closed” position and details of the metallic after-seal in a sectional view and c) a detailed view of section H of the in Fig. 1. Piston valve shown in the “open” position in a sectional view.

[0024] The Fig. 2 also shows a detailed view of section H of the in Fig. 1. Piston valve shown (see a)) and b) an exploded view of the piston including the connecting parts.

[0025] The sealing surface of the piston lower part (4) rests against a corresponding conical sealing surface of a valve housing (1) under axial pressure, forming a force-fit connection. This geometric design creates a self-centering metallic seal that enables high surface pressures while simultaneously being low-risk during assembly.

[0026] In the second zone, a permanently elastic piston valve ring (2) is then attached as Fig. 4 shows, made of laminated expanded graphite (8) and provided with stainless steel sheet inserts (9), for example stainless steel 1.4401.

[0027] The Fig. Figure 4 shows a) a detailed view of the piston valve ring in a sectional view and b) a perspective image of the surface structure of the metallic spiking plate.

[0028] The piston valve ring (2) is installed axially preloaded between the piston lower (4) and piston upper (3). The graphite ring, i.e., the graphite laminate (8), has a high resilience and adapts flexibly to changes in temperature and pressure.

[0029] In the third zone, according to Fig. 3 A metallic secondary seal is provided between the piston head (3) and the valve housing (1). The sealing surface of the piston head (3) is also convex, cf. Fig. 3 Section AC, and is positively connected to a corresponding conical sealing surface of the valve housing (1), thereby realizing a redundant metallic seal as a safety and emergency seal.

[0030] This three-stage sealing structure ensures permanently leak-proof operation even at temperatures above 400 °C and pressures up to 160 bar. At the same time, the risk of sudden leakage failure is significantly reduced. Reference symbol list 1 Valve housing 2 piston valve ring 3 Piston top 4 Piston base 5 threaded pin with pin 6 cylinder pin 7 spindles 8 Graphite laminate 9 skewer trays H A detailed view of section H of the in Fig. 1. Piston valve shown in the “closed” position of the piston representation including connecting parts of a sectional view. F A detailed view of section F of the in Fig. 1. Piston valve of the piston valve ring built into the piston in a sectional view. QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] DE 10 2010 000 000 A1

[0005]

Claims

[1] Piston valve comprising a piston sealing unit (2, 3, 4, 5, 6, 7) in the passage area of ​​a valve housing (1), characterized by , that the piston sealing unit (2, 3, 4, 5, 6, 7) comprises a metallic pre-seal formed from the piston lower part (4) and the valve housing (1), a permanently elastic piston valve ring (2), in particular made of laminated graphite (8), with a splintered sheet insert (9), and a metallic secondary seal formed from the piston upper part (3) and the valve housing (1), wherein the piston valve ring (2) is axially arranged between the metallic pre-seal and the metallic secondary seal and is elastically deformed and resealed under contact pressure in order to ensure a multi-stage seal between the piston lower part (4), piston upper part (3), piston valve ring (2) and the valve housing (1). [2] Piston valve according to claim 1, characterized by, that the metallic pre-seal is arranged between the piston lower part (4) and the valve housing (1). [3] Piston valve according to claim 1 or 2, characterized by , that the metallic after-seal is arranged between the piston top (3) and the valve housing (1). [4] Piston valve according to any one of claims 1 to 3, characterized by , that the skewer plate insert (8) is made of stainless steel. [5] Piston valve according to any one of claims 1 to 4, characterized by , that the laminated expanded graphite (9) of the piston valve ring (2) has a springback of at least 10% of the compression. [6] Piston valve according to one of the preceding claims, characterized by , that the metallic pre-seal of the piston lower part (4) is convex and rests forcefully on a correspondingly conical sealing surface of the valve housing (1). [7] Piston valve according to one of the preceding claims, characterized by, that the metallic after-seal of the piston top (3) is convex and rests forcefully on a correspondingly conical sealing surface of the valve housing (1).

Images