Triple eccentric butterfly valve gate structure parameter change impact analysis to butterfly plate

Triple eccentric butterfly valve gate is the basic structure characteristics of the valve stem position determines the two eccentric axial and radial, form the butterfly plate the gradient of the cone made another Angle eccentric. In the design of triple eccentric butterfly valve door to reasonable design each parameter value to avoid interference phenomenon. In this paper, the qualitative analysis of the structural parameters of the triple eccentric butterfly valve gate change on the influence of the interference phenomenon. Valve door close in the state of the butterfly plate and the valve seat sealing surface contact, completely fit everywhere. The butterfly plate around the rotary axis rotation Angle, without interference if the rotation process, the valve door by interference test. Set P for butterfly plate sealed from any point on the surface, because of the point P track of rotary axis rotate as a circle, a point P and perpendicular to the rotation axis plane intersecting the valve seat sealing surface M, and the curve in the x & the isin; ( e - b/ 2 , e + b/ 2 ] For a or a hyperbola in two parts. If in the process of rotating circular trajectory within the scope of the sealing surface width is always in the interior of the hyperbolic trajectories, said the butterfly plate sealing surface will not interference with the valve seat sealing surface, if in the process of rotating circular trajectory, the outside of the seal face width range inner hyperbolic trajectories disc sealing surface will interference with the valve seat sealing surface. Use of procedures can be concluded that some parameters not occurred the scope of interference. With DN = 200 mm, the PN = 215 mpa butterfly valve gate as an example is analyzed. From the perspective of the butterfly plate interference does not occur to the following conclusion. (1) with the increase of a. & delta; Linear increase after reduction first, in order not to make the valve door produces interference phenomenon, should choose a value. (2) with the increase of e & delta; Approximate straight down, so e near the minimum value in general. (3) with the increase of b & delta; Too much, so b values should not be commonly. (4) as & alpha; The increase of & delta; After the first increased, & alpha; The value of the near should choose a turning point. (5) with & beta; The increase of & delta; The approximate straight increase, so the & beta; Should choose larger values. In each parameter determination of triple eccentric butterfly valve door can only determine many parameters in the process of a certain range, the parameter selection in the process of rationalization of main factor are sealed, torque and interference, and the valve gate structure and so on. Can take advantage of the method in the process of parameter determination interference does not occur to verify the parameter range, and then according to the requirements of the valve gate structure design of the other to choose the parameters, and so the valve door in the process of product design that is more convenient for interference inspection, improve the efficiency of product design.