Structural Improvement Of Fluorine-lined Valve And Fluorine-lined Ball Valve Seat

1.Lined Ball Valve Improvement of valve body structure

In the past, valve bodies were mostly castings, and there were uncertain factors such as pores, sand holes, looseness, slag inclusions, shrinkage holes, cracks, etc. during the casting process. , which affect the overall mechanical properties of the valve. In order to develop in the direction of high parameters and high performance, give full play to the characteristics of riveting and welding processing capabilities, refer to similar products at home and abroad, and adopt the optimization design method of mixed discrete variables and steel plate materials with good toughness. Compared with castings, the valve body wall thickness of welded steel plates can be thinner, with high strength and good toughness, and the mass is reduced by about 1/6 compared with the cast valve body.

2. Improvement of valve seat structure

The sealing structure of the fluorine-lined ball valve seat is the key to the sealing performance of the ball valve and directly affects the service life of the ball valve. The original valve seat sealing ring structure has a large contact area with the ball core due to the large angle of the valve seat sealing ring, the ball core is tightly held, and the torque is relatively large. Take the DN 400 ball core valve seat as an example, the mass is 3kg, the valve seat sealing ring is in line contact with the ball core, and the contact area is small, which makes the valve open flexibly and the quality of the valve seat sealing ring is reduced by about 1/3.

3. Improvement of ball core structure

The original ball core diameter of the fluorine-lined ball valve is too large, and the valve body cavity is too large, resulting in material waste and low utilization rate. The original ball core mass is 380kg, and the improved ball core mass is 285kg. The improved ball core strength can ensure the sealing position. After the improvement, the ball core filling layer is increased, and the wear-resistant layer material basalt cast stone is used for more firm adhesion, and the wear-resistant material will not fall off.

According to the introduction of the vacuum technology network, the inner diameter of the through-hole ball valve is d=DN, the ball diameter is R=018DN, and the ball surface distance L<root square (D2-d2). The improved ball core fully meets the requirements of the literature. D ball valve outer diameter.

4. Improvement of the upper stem structure

The original DN400 stem of the fluorine-lined ball valve is made of 2Cr13Φ. Due to the O-ring and O-ring of the upper stem and the O-ring and 150 bar of the upper stem, the DF composite bearing has the same size and the composite bearing has the same size. The DF composite bearing is open, which is inconvenient to assemble and troublesome. For this reason, the upper stem is improved. After the improvement, the DF composite bearing size is inconsistent when driving one step at the seal of the stem and the valve body, and each step has a rounded corner to avoid the occurrence of gnawing O-rings. After recalculating the stem strength, the stem diameter can be reduced by about 20% compared with the original design.

5. Improvement of the lower stem structure

The original lower stem consists of a lower shaft and a flange. First, the lower shaft and flange are stopped, then welded and annealed. According to the drawings, all parts of the vehicle are inconvenient to adjust during assembly. Therefore, the improvement of the lower stem is as follows. Changing the lower stem from a part to two separate parts can save the annealing process, facilitate processing, and reduce costs a lot.