TWM605256U - High temperature and high pressure resistant needle valve - Google Patents

Abstract

The model relates to a high temperature and high pressure needle valve, which comprises a valve body, a valve stem, a packing nut, a packing and a valve core. The packing is built in the valve stem hole and is filled around the outer side wall of the valve stem. The packing is compressed by the packing nut. An internal thread is provided on the inner side wall of the valve body. Correspondingly, an external thread that matches the internal thread is provided on the outer wall of the middle section of the valve stem, so that the position of the valve core relative to the transition chamber can be changed by rotating the valve stem. , So as to realize the on/off of the medium inlet and the medium outlet. The filler is composed of a high temperature resistant soft filler layer and a metal filler layer, wherein the metal filler layer is arranged in two layers, and they are respectively pressed against the top surface and the bottom surface of the high temperature resistant soft filler layer. In the technical scheme disclosed in the present invention, the filler is set in a composite structure. In this way, the existence of the metal filler layer can effectively reduce the creep number of the filler when subjected to high temperature, ensure the stability of the sealing effect, and reduce the subsequent Maintenance costs.

Description

High temperature and high pressure resistant needle valve

The model relates to the technical field of valve manufacturing, in particular to a high temperature and high pressure resistant needle valve.

The high-pressure needle valve has the advantages of small fluid resistance, simple structure, compactness, reliable sealing, convenient operation and maintenance, and wide application range. It is widely used in machinery, chemical, petroleum and other industries. Its valve core is driven by the valve stem, and Move up and down along the axis of the valve stem to realize the opening/closing of the valve.

The valve stem is sealed by squeezing the packing nut along the axial direction of the packing to force the packing to deform in the radial direction, so as to achieve the purpose of sealing. In the prior art, polytetrafluoroethylene is usually used as a filler, but it has the following problems: polytetrafluoroethylene filler is easily restricted by the temperature range of use, and at the same time it has the defect of large creep number (easy to lose elasticity and easy to be squeezed). After a period of time, the newly replaced packing needs to be further compacted, otherwise it is prone to leakage, which increases the subsequent maintenance investment. Therefore, it is urgent for technicians to solve the above problems.

The technical problem to be solved by the new model is to provide a high temperature and high pressure resistant needle valve with simple structure design and reliable sealing.

In order to solve the above technical problems, the present model relates to a high temperature and high pressure resistant needle valve, which includes a valve body, a valve stem, a packing nut, a packing, a valve core and a handle. The spool is set on the valve The lower end of the rod. A medium inlet, a medium outlet, a transition cavity and a valve stem hole for inserting the valve stem are arranged inside the valve body. The transition cavity is arranged directly below the valve stem hole and communicates with it. The packing is built in the valve stem hole and is filled around the outer side wall of the valve stem. The packing is compressed by a packing nut. Correspondingly, a first external thread is provided on the outer side wall of the upper half of the valve stem hole, and a first internal thread that matches the first external thread is provided on the inner side wall of the packing nut. . A second internal thread is provided on the inner side wall of the valve body. Correspondingly, a second external thread that matches the second internal thread is provided on the outer wall of the middle section of the valve stem. The valve core can be changed by rotating the valve stem. Relative to the position of the transition cavity, the media inlet and the media outlet can be switched on/off. The filler is composed of a high temperature resistant soft filler layer and a metal filler layer, wherein the metal filler layer is arranged in two layers, and they are respectively pressed against the top surface and the bottom surface of the high temperature resistant soft filler layer.

As a further improvement of the above technical scheme, the high-temperature resistant soft filler layer is compacted and compounded by non-asbestos lint and flake graphite powder.

As a further improvement of the above technical solution, the second external thread is a trapezoidal thread, and a wear-resistant coating is provided on its surface.

As a further improvement of the above-mentioned technical solution, the lower end of the valve core is set in a cone shape with a large upper and a smaller bottom, and correspondingly, the transition cavity adapted to it is also set in a cone shape.

As a further improvement of the above technical solution, the handle is composed of a rotating part and a connecting part arranged in order along the up and down direction, wherein a threaded hole is opened on the side wall of the connecting part to achieve fixation with the valve stem by means of a handle fixing screw , Correspondingly, the corresponding position of the valve stem is provided with a supporting cut plane.

As a further improvement of the above technical solution, a friction increasing groove is provided on the side wall of the rotating part. The number of friction-increasing grooves is set to be multiple, and they are along the central axis of the rotating part Perform circumferential uniform distribution.

Compared with the high-pressure needle valve with a traditional design structure, in the technical solution disclosed in the present invention, the filler is arranged in a composite structure, in which the presence of a metal filler layer can effectively reduce the creep number of the filler when subjected to high temperature and ensure The stability of the sealing effect reduces subsequent maintenance costs.

1: Valve body

41: Metal filler layer

11: Medium inlet

12: Medium outlet

13: transition cavity

14: Stem hole

2: Valve stem

21: Lean against the cut plane

3: Packing nut

4: filler

42: High temperature resistant soft filler layer

5: Spool

61: Rotating part

611: Friction Increased Groove

62: Connection

621: threaded hole

6: handle

7: Handle fixing screw

Figure 1 is an exploded schematic diagram of the new type of high temperature and high pressure needle valve.

Figure 2 is a front view of the new type of high temperature and high pressure needle valve.

Figure 3 is a left view of the new type of high temperature and high pressure needle valve.

Fig. 4 is a cross-sectional view of Fig. 2.

Fig. 5 is a partial enlarged view of I in Fig. 4.

Fig. 6 is a structural diagram of the handle in the high-pressure needle valve of the present invention.

In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "upper", "lower", "left", "right", etc. is based on the orientation or positional relationship shown in the drawings, and is only for It is convenient to describe and simplify the description of the present invention, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present invention.

The technical solutions disclosed in the present invention will be described below with examples. Figures 1, 2 and 3 respectively show the exploded schematic diagram, front view and left view of the high temperature and high pressure resistant needle valve of the present invention, which are mainly composed of valve body 1, Stem 2, packing nut 3, packing 4, spool 5, handle 6, etc. Partial structure, wherein the valve core 5 is provided at the lower end of the valve stem 2. The valve body 1 is provided with a medium inlet 11, a medium outlet 12, a transition chamber 13 and a valve stem hole 14 into which the valve stem 2 is inserted. The medium outlet 12 and the medium inlet 11 are respectively arranged on the left and right sides of the transition cavity 13. The transition cavity 13 is arranged directly below the valve stem hole 14 and communicates with it. The packing 4 is built in the valve stem hole 14 and is filled around the outer side wall of the valve stem 2. The packing 4 is compressed by the above-mentioned packing nut 3. Correspondingly, a first external thread is provided on the outer side wall of the upper half of the valve stem hole 14, and the inner side wall of the packing nut 3 is provided with the first external thread. The first internal thread. A second internal thread is provided on the inner side wall of the valve body 1. Correspondingly, a second external thread that matches the second internal thread is provided on the outer wall of the middle section of the valve stem 2, so that the valve stem 2 can be rotated The position of the spool 5 relative to the transition cavity 13 is changed to realize the on/off of the medium inlet 11 and the medium outlet 12. What needs to be emphasized here is that the filler 4 is composed of a high temperature resistant soft filler layer 42 and a metal filler layer 41. The metal filler layer 41 is arranged in two layers, and is pressed against the top surface of the high temperature resistant soft filler layer 42. The bottom surface (as shown in Figure 5). In this way, the metal filler layer 41 functions as a stability holder, which can effectively reduce the creep number of the filler when subjected to high temperature, ensure the reliability and stability of the sealing effect, and reduce the subsequent maintenance cost.

Furthermore, the above-mentioned high-temperature resistant soft packing layer 42 can be compacted and compounded with asbestos-free lint and flake graphite powder, and has a high high-temperature creep number, making the high-pressure needle valve suitable for high-temperature environments above 450°C.

In consideration of reducing the impact of the impact force on the valve core, the above-mentioned media inlet 11 and media outlet 12 are arranged at an incline of 10-25° along the horizontal direction (as shown in Figure 4). In this way, on the one hand, it improves The flexibility of the displacement of the spool 5 is improved, and its service life is improved.

It is known that when the valve stem 2 performs up and down reciprocating motion relative to the valve body 1, it will inevitably cause abrasion on the thread pair, which will reduce the matching accuracy of the two and lead to the filling The material 4 is repeatedly affected by the lateral force, which affects the reliability of the high-pressure needle valve seal. For this reason, the above-mentioned second external thread and the second internal thread are both set as trapezoidal threads, and the surface layer is provided with a wear-resistant coating. As a result, the thread pair has strong wear resistance, and even if wear occurs At this time, the trapezoidal thread itself has an automatic compensation function to ensure a good matching relationship between the valve stem 2 and the valve body 1.

As a further optimization of the above-mentioned high-temperature and high-pressure needle valve, the lower end of the valve core 5 can be set to be a tapered shape with a large upper and a small bottom. As shown in Figure 4), in this way, on the one hand, the fitting accuracy of the spool 5 relative to the transition cavity 13 is effectively ensured, and the effective isolation of the medium inlet 11 and the medium outlet 12 is ensured; on the other hand, when the spool 5 When the side wall relative to the transition cavity 13 is worn out, the taper fitting mode can immediately compensate itself to prevent leakage.

Of course, an annular installation groove for accommodating the valve core 5 can also be provided on the end side wall of the valve core 5 to cooperate with the installation of a sealing ring (not shown in the figure), thereby further preventing the valve core 5 from leaking relative to the transition cavity 13 The occurrence of the phenomenon.

As a further refinement of the connection structure of the handle 6 described above, the handle 6 is composed of a rotating portion 61 and a connecting portion 62 arranged in an up and down direction (as shown in FIG. 6), wherein, on the side wall of the connecting portion 62 A threaded hole 621 is opened to realize the fixation with the valve stem by means of the handle fixing screw 7. Correspondingly, an abutting plane 21 is provided at the corresponding position of the valve stem 2. In this way, on the premise of ensuring the reliability of the connection between the handle 6 and the valve stem 2, the time required for the separation of the two is as low as possible, and the difficulty of subsequent maintenance is reduced.

Furthermore, in order to facilitate the rotation of the handle 6 during actual use, a friction increasing groove 611 (as shown in FIG. 6) may also be provided on the side wall of the rotation portion 61 to prevent operation The hands of the personnel slip during the rotating process, which improves the comfort of operation. Specifically, the number of the friction increasing grooves 611 is set to be multiple, and they are evenly distributed in the circumferential direction along the central axis of the rotating portion 61.

The above description of the disclosed embodiments enables those skilled in the art to realize or use the present invention. Various modifications to these embodiments will be obvious to those skilled in the art, and the general principles defined in this document can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown in this article, but should conform to the widest scope consistent with the principles and novel features disclosed in this article.

41: Metal filler layer

42: High temperature resistant soft filler layer

Claims (6)

A high temperature and high pressure resistant needle valve, including a valve body, a valve stem, a packing nut, a packing, a valve core, and a handle; the valve core is arranged at the lower end of the valve stem; a medium inlet is arranged inside the valve body, The medium outlet, the transition cavity, and the valve stem hole into which the valve stem is inserted; the transition cavity is arranged directly below the valve stem hole and communicates with it; the packing is built in the valve stem hole, and Filling is performed around the outer side wall of the valve stem; the filler is compressed by the packing nut. Accordingly, a first external thread is provided on the outer side wall of the upper half of the valve stem hole, and the filler The inner side wall of the nut is provided with a first inner thread adapted to the first outer thread; a second inner thread is provided on the inner side wall of the valve body, and correspondingly, a middle outer wall of the valve stem is provided The second external thread adapted to the second internal thread can change the position of the valve core relative to the transition cavity by rotating the valve stem, thereby realizing the medium inlet and the medium On/off of the outlet; the filler is composed of a high temperature resistant soft filler layer and a metal filler layer, wherein the metal filler layer is arranged in two layers, and they are respectively pressed against the top surface and the bottom surface of the high temperature resistant soft filler layer . According to the high temperature and high pressure needle valve described in claim 1, the high temperature resistant soft packing layer is compacted and compounded by non-asbestos lint and flake graphite powder. According to the high temperature and high pressure resistant needle valve of claim 1 or 2, the second external thread is a trapezoidal thread, and a wear-resistant coating is provided on its surface. For the high-temperature and high-pressure needle valve described in claim 1 or 2, the lower end of the valve core is set in a cone shape with a large upper and a smaller bottom. Correspondingly, the transition cavity adapted to it is also set as a cone shape. According to the high temperature and high pressure needle valve of claim 1 or 2, the handle is composed of a rotating part and a connecting part arranged in an up-down direction, wherein a threaded hole is opened on the side wall of the connecting part to The fixation with the valve stem is achieved by means of a handle fixing screw, and correspondingly, an abutting plane is provided at the corresponding position of the valve stem. According to claim 5, the high temperature and high pressure resistant needle valve is provided with friction increasing grooves on the side wall of the rotating part; the number of the friction increasing grooves is set to be multiple, and they are arranged along the rotating part. The central axis is uniformly distributed in the circumferential direction.

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