Four-way stop valve

Abstract

A four-way stop valve comprises stop valves, each stop valve mainly comprises an executing mechanism, a support, a valve rod and a valve seat sealing face, the three stop valves are arranged in the space at an angle of 60 degrees to form a four-way umbrella-shaped stop valve, the four-way valve comprises three branch flow channels and a main body flow channel, and the branch flow channels and the main body flow channel are communicated through a spherical cavity in the middle; a spherical crown type scraper is arranged at the end of the valve rod, a sealing face is arranged on the portion, behind the spherical crown type scraper, of the valve rod, the profile curve of the spherical crown type scraper is matched with the notch in the spherical cavity, and the inner concave face of the spherical crown type scraper is matched with a spherical crown of the corresponding part of the inner surface of the spherical cavity. The inner surface of the spherical crown type scraper and the inner surface of the spherical cavity form a complete sphere; a guide groove is formed in the other end of the valve rod, and the guide groove and the guide pin move in a matched mode. According to the invention, not only can a good sealing effect be ensured, but also the functions of reversing, shunting, collecting and the like of media can be realized.

Description

Technical Field

[0001] The invention belongs to the technical field of valve manufacturing, and in particular relates to a four-way stop valve. Background Art

[0002] With the rapid development of science and technology, the requirements for valve sealing are getting higher and higher. The existing valve seat sealing pair is generally set at the end of the closing member, causing the medium to directly flush the sealing surface and cause the seal to fail and leak. In addition, in some devices, the medium often cokes and sticks on the valve seat sealing surface and the surrounding area, and is sandwiched between the sealing surfaces when closed. Due to loose closure, leakage occurs, resulting in seal failure. In order to improve the sealing performance in the existing technology, measures are taken on the sealing structure, but no corresponding measures are taken to improve the sealing position. Summary of the invention

[0003] The present invention provides a four-way stop valve which can not only ensure a good sealing effect but also realize functions such as medium reversal, flow diversion and confluence when in working state.

[0004] To this end, the technical solution adopted is: A four-way stop valve comprises a stop valve, which mainly comprises an actuator, a bracket, a valve stem, and a valve seat sealing surface. The three stop valves are arranged at 60 degrees in space to form a four-way umbrella-shaped stop valve. The four-way valve comprises three branch flow channels and a main flow channel, and the branch flow channels and the main flow channel are connected through a spherical cavity in the middle; the end of the valve stem is a spherical crown scraper, and a sealing surface is provided on the valve stem behind the spherical crown scraper. The contour curve of the spherical crown scraper is adapted to the notch on the spherical cavity, and the inner concave surface of the spherical crown scraper is adapted to the spherical crown of the corresponding part of the inner surface of the spherical cavity. When the sealing surface on the valve stem is tightly fitted with the valve seat sealing surface to form a seal, the inner surface of the spherical crown scraper and the inner surface of the spherical cavity form a complete sphere; the other end of the valve stem is provided with a guide groove, and the guide groove and the guide pin installed on the bracket are adapted to move.

[0005] A guide bearing is installed at the end of the guide pin.

[0006] The inner concave surface of the spherical crown scraper is provided with a hard alloy spray layer.

[0007] The three branch flow channels, the spherical cavity and the outer wall of the main flow channel are provided with heat-insulating sleeves.

[0008] The present invention is mainly used in the cut-off valve with coking particles and easy coking medium. In the conventional cut-off valve, the top of the valve stem is generally flat or conical, and the head of the valve stem is spherical. When closed, it completely forms a complete spherical surface with the main spherical channel and also becomes a part of it. The front end of the valve stem and the channel reach a matching state, which not only plays a guiding role, but also prevents the medium from entering and washing the sealing surface, thereby ensuring the sealing surface and achieving reliable sealing. The present invention has reliable sealing, high precision, stable medium flow, and extends the service life of the valve. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 It is a schematic diagram of the planar structure of the present invention; Figure 2 It is a partial schematic diagram of the rotary guide ball crown type scraper valve head of the present invention; Figure 3 It is a schematic diagram of a ball crown type scraper valve head; Figure 4 It is a schematic diagram of the three-dimensional structure of the present invention; In the figure: hand wheel 1, gear box 2, bracket 3, guide pin 4, guide bearing 5, guide groove 6, valve stem 7, valve stem sealing surface 8, spherical crown scraper 9, branch flow channel 10, valve seat sealing surface 11, main body spherical channel 12, insulation sleeve 13. DETAILED DESCRIPTION

[0010] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0011] Reference Figure 1 , Figure 2 , Figure 3 A four-way stop valve includes a stop valve, which mainly includes an actuator, a bracket, a valve stem, and a valve seat sealing surface. The three stop valves are arranged at 60 degrees in space to form a four-way umbrella stop valve. The four-way includes three branch flow channels and a main flow channel. The branch flow channel and the main flow channel are connected through a spherical cavity in the middle; the end of the valve stem 7 is a spherical crown scraper 9, and a sealing surface 8 is provided on the valve stem behind the spherical crown scraper 9. The contour curve of the spherical crown scraper is adapted to the notch on the spherical cavity, and the inner concave surface of the spherical crown scraper is adapted to the spherical crown of the corresponding part of the inner surface of the spherical cavity. When the sealing surface on the valve stem and the valve seat sealing surface are tightly fitted to form a seal, the inner surface of the spherical crown scraper and the inner surface of the spherical cavity form a complete sphere; the other end of the valve stem is provided with a guide groove, and the guide groove and the guide pin installed on the bracket are adapted to move. A guide bearing 5 is installed at the end of the guide pin 4. The limit bearing reduces friction, and the valve stem only lifts but does not rotate.

[0012] In the present invention, the sealing surface is arranged behind the closing member to avoid or reduce direct erosion of the sealing surface by the medium.

[0013] When the channels of the three branch flow channels in the present invention are closed, a spherical cavity is formed. The opening and closing of different branches can reverse, divert and converge the medium; each passage forms an angle of 60 degrees in space, which not only satisfies the non-interference of the operating space, but also satisfies the layout of the spherical cavity of the casting body and the branch channels.

[0014] The valve body of the four-way valve of the present invention is integrally cast, the butt-welded flange connection adopts the BW form, the valve stem and the valve disc are an integral whole, and each channel medium flow or cutoff is controlled by an independent operating mechanism, which will not be affected by other flow channel control systems, and is convenient and flexible to operate and maintain.

[0015] The inner concave surface of the spherical crown scraper 9 is provided with a hard alloy spray layer to prevent the medium from scouring, and the closed state prevents the medium from scouring the sealing surface.

[0016] The three branch flow channels, the spherical cavity and the outer wall of the main flow channel are provided with an insulation sleeve 13. When the medium is in a slurry state, hot steam can be passed to prevent crystallization, ensuring that the hot steam passes through the insulation sleeve so that the medium temperature will not drop and crystallize or coke, so that the valve seal is reliable.

[0017] In the working process of the present invention, when the valve is opened and closed, the actuator drives the valve stem to move, the valve stem only rises and falls but does not rotate, and the ball-cap scraper scrapes and cleans the attachments around the valve seat to ensure the cleanliness around the valve seat. When the valve stem is lifted and the guide pin reaches the top of the guide groove, the valve stem stops lifting and reaches the fully open state. At this time, the ball-cap valve head is connected with the branch flow channel, and the medium flows through to reduce the flow resistance and make a smooth transition. Similarly, when closing, the actuator drives the valve stem to move, and the movement trajectory moves up and down according to the guide groove on the valve stem. The guide pin drives the guide bearing to slide in the guide groove. The ball-cap scraper scrapes and cleans the attachments around the valve seat again in the opposite direction of lifting, and again ensures the cleanliness around the valve seat. When the valve stem sealing surface fits the valve seat sealing surface, it reaches the closed state. At this time, the ball-cap valve head and the spherical cavity of the valve body form an integral spherical surface. At this time, the front end of the valve stem also forms a part of the spherical cavity, so it is called a ball-cap valve head. The medium flowing through the middle cavity cannot reach the sealing surface, thereby achieving reliable sealing. The length of the "shovel" shape formed by this ball crown valve head depends on the eccentricity between the center of the valve stem and the middle cavity. The more eccentric it is, the longer the shovel shape is, and vice versa.

[0018] See Figure 3 The bottom of the spherical crown scraper 9 is a shovel-shaped scraper structure, and the shovel-shaped concave surface is a part of the spherical crown of the spherical inner surface of the main spherical channel 11. The shovel is sharp around, which can play a self-cleaning role during the switching process, scraping off the medium adhered around the valve seat to ensure that there is no slag between the sealing surfaces during the closing process, and the sealing is reliable.

Claims

1. A four-way stop valve, comprising a stop valve, the stop valve mainly comprising an actuator, a bracket, a valve stem, and a valve seat sealing surface, characterized in that: The three stop valves are arranged at 60 degrees in space to form a four-way umbrella stop valve, the four-way valve comprising three branch flow channels and one main flow channel, the branch flow channels and the main flow channel being connected through a spherical cavity (12) in the middle; the end of the valve stem (7) is a spherical crown scraper (9), a sealing surface (8) is provided on the valve stem behind the spherical crown scraper (9), the contour curve of the spherical crown scraper (9) is matched with the notch on the spherical cavity (12), and the inner concave surface of the spherical crown scraper (9) is matched with the spherical crown of the corresponding part of the inner surface of the spherical cavity (12), when the sealing surface (8) on the valve stem (7) and the valve seat sealing surface (11) of the stop valve are tightly fitted to form a seal, the inner surface of the spherical crown scraper (9) and the inner surface of the spherical cavity (12) form a complete sphere; the other end of the valve stem (7) is provided with a guide groove (6), the guide groove (6) and the guide pin (4) installed on the bracket are adapted to move.

2. A four-way stop valve according to claim 1, characterized in that: A guide bearing (5) is installed at the end of the guide pin (4).

3. A four-way stop valve according to claim 1, characterized in that: A hard alloy spray coating is provided on the inner concave surface of the spherical crown scraper (9).

4. A four-way stop valve according to claim 1, characterized in that: The three branch flow channels, the spherical cavity (12) and the outer wall of the main flow channel are provided with a heat-insulating sleeve (13).

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