FR2499663A1 - VALVE VALVE SEALING - Google Patents

Abstract

SEALING PROCESS FOR A VALVE INCLUDING A MOBILE VALVE AND A FIXED METAL SEAT WHICH INCLUDE SEALING SURFACES. THESE SURFACES ARE MADE OF MALLEABLE MATERIAL, THE SEALING SURFACE OF THE VALVE IS INCLINED WITH RESPECT TO THE DIRECTION OF MOVEMENT OF THE VALVE AND IT IS REALIZED IN MATERIAL SOFTENER THAN THE SEAT. AT LEAST THE SEALING SURFACE 5 OF THE VALVE 1 IS GIVEN A SENSITIVELY SPHERICAL SHAPE OR OF ANY OTHER BODY OF REVOLUTION GENERATED BY A CURVED LINE. THE VALVE DIMENSION IS DETERMINED, ACCORDING TO THE NORMAL CLOSING FORCE OF THE VALVE, SO THAT THIS FORCE CAUSES A PERMANENT DEFORMATION OF THE VALVE TALLABLE BY SEAT 6, IN ORDER TO KEEP THE GENERAL FORM OF SEALING OF THE VALVE AND OF THE SEAT INDEPENDENT OF THE WEAR OF THE SEALING SURFACE OF THE VALVE. THE INVENTION MAKES IT POSSIBLE TO KEEP THE WATERPROOFING FOR A LONGER PERIOD OF USE.

Description

VALVE VALVE SEALING

  The present invention relates to a method,

  as well as a mechanism for the implementation of this

  given for the sealing of a seat valve and valve

  having a movable shutter member and a metal seat

  stationary, sealing surfaces being provided on

  the shutter element and on the seat, these surfaces of

  with a malleable material, the sealing surface

  of the shutter element being inclined with respect to the

  movement of the latter and the surface area

  the slackness of the shutter element being more

  the sealing surface of the seat.

  In the usual way, the surface of the seat of a

  Pope is made of harder material than the ob-

  turner or flapper. The seat surface is usually on a sharp edge and it partially penetrates the body of

  valve, which is softer, which creates gaps and

  in this body when the valve is closed. Since it is impossible to find exactly the same relative position between the valve and the valve seat at each closing of the valve, the repeated deformation of the valve causes leakage of the valve, even after a small

  number of closing and opening cycles.

  Attempts have been made to avoid wear and tear on the surfaces of

  of a valve, through the use of similar materials

  hardness for the seat and the flap. However, in

  tick, it is impossible to avoid wear. As a result, the valve leaks after a certain period of service, due to

  of the wear that occurs in the sealing surfaces.

  According to another known method, the valve is made of a harder material than the seat, as described in US Pat. No. 3,761,052 which relates to a sliding shutter valve. However, the wear problems of a valve of this type differ greatly from those of a flap valve and this known construction does not apply.

so not to this last.

  The present invention relates to a valve

  flap valve, which retains its watertight

  long service life despite a functioning

  repeated and wear. The invention is characterized

  what is given at least to the sealing surface of the

  shutter member or check valve a substantially spherical shape or the shape of another body of revolution generated by a curved line, and in that the valve has a dimension such as, with respect to the normal force of closure of the

  valve, that this force gives rise to permanent deformation

  the malleable valve through the valve seat. By

  following, the general tightness of the valve and seat of sou-

  pope is preserved, regardless of the wear of the sealing surface of the valve. Thus, thanks to the malleability of

  valve, the sealing surfaces may retain their

  me sealing, regardless of normal wear and tear. same

  if the position of the flap is slightly different

  closing, the valve deforms each time by

  appropriate seat against the harder seat and the

  you tight. Thus, the sealing surfaces of the valve

  eg are reprofiled in service. The seal is still

  improved by the fact that the valve seat, that is,

  to say the undeformed part, is fixed.

  The portion of the sealing surface of the valve in contact with the seat is enlarged by the deformations produced by the closing force, so

  that the valve is profiled in accordance with the surface of

  seat sealing. In this way, the contact area between the sealing surfaces increases due to

  wear, which is favorable for the sealing of the

  - 3 - Pope. In a preferred application of the invention, the profile of the seat sealing surface, in axial section, is given a much larger radius of curvature.

  than that of the corresponding profile of the surface of

  the check valve is fairly flat, the profile of the seat being preferably rectilinear. The sealing part of the valve can be

  made of cobalt-chromium alloy, for example in "Stel-

  It is advantageous to use different qualities

  cobalt-chrome alloys so as to choose a softer quality for the valve than for the seat. It has been found that the increase of the contact area

  during use is very small, which favors

  for the preservation of the geometric form of the

  sealing surface. In special cases, for example

  in valves used for fluids containing

  chlorine, the sealing part of the valve may

  can be made of polytetrafluoroethylene or plastic material of corresponding properties, the seat

  being made of acid resistant steel.

  The invention also relates to a device

  sealing valve for valve valve designed

as described above.

  The invention will be better understood in the light

  description of its embodiment, not limited to

  tive, shown in the accompanying drawing which is a cross-section

  axial valve of a valve according to the invention.

  In the drawing, reference numeral 1 denotes a valve, connected to a rod 2 which can move in a bore 8 formed in a cap 3 of a valve body 4. The valve comprises a portion 5, in the form of a sphere segment , which constitutes the sealing surface of the valve. A seat

  fixed conic 6 is placed in the body 4. According to the invention

  tion, the part 5 of the valve is made of softer material than that of the seat 6 so that, on closing

  of the valve, the part 5 of the valve deforms slightly

  against the harder seat 6. This allows the seat

  to stay waterproof, despite its wear. Part 5 is fixed to the valve 1 by welding. The sealing of the rod 2 in the bore 8 of the cap 3 is not described in detail because it is of the usual type and is not within the scope of the invention. The valve comprises, in known manner, an inlet orifice 9, an outlet orifice 10 and a seal

  7 disposed between the body 4 and the removable cap 3.

  It is understood that modifications of detail may be made in the form and implementation

  of the method and the device according to the invention, without

shot from the frame of it.

-5-

Claims (6)

  1. Method of sealing a seat valve   and valve comprising a shutter member or poppet valve   bile and a fixed metal seat, sealing surfaces   being provided on the flap and the seat, these surfaces of   sealing being made of malleable material, the sealing surface   the check valve being sloped in relation to the direc-   movement of the valve and the sealing surface of the valve being softer than that of the sealing surface of the seat, characterized in that it gives at least the sealing surface (5) of the valve   (1) a substantially spherical shape or the shape of a   a body of revolution generated by a curved line, and in that the valve has a dimension such that, relative to the normal closing force of the valve, this valve   force causes a plastic deformation of the mal-   seat (6), which makes it possible to   general flapper and seat integrity regardless of   any wear on the sealing surface of the valve.   2. The process of claim 1, wherein   in that the profile of the water surface is   the seat diameter, in axial section, a bending riycn much larger than that of the corresponding profile of the sealing surface of the valve, the profile of the seat being preferably rectilinear.   3. A process according to claim 1 or 2,   characterized in that the sealing surfaces of the valve and the seat, respectively, are made of different qualities of the chromium-cobalt alloy called "Stellite",   which is used the hardest quality for the seat.   4. Process according to claim 1 or 2,   characterized in that the sealing surface of the valve is made of polytetrafluoroethylene or plastic material of corresponding properties, and in that the sealing surface of the seat is made of acid resistant steel.   5. Sealing device of a seat valve   ge, for the implementation of the process according to one   of the preceding claims, which comprises a   movable valve (1) and a fixed metal seat (6), sealing surfaces being provided on the valve and on   the seat, these sealing surfaces being made of   the sealing surface of the valve being inclined with respect to the direction of movement of the valve and the sealing surface of the valve being softer than that of the sealing surface of the seat, characterized in that minus the sealing surface (5) of the flap   (1) is substantially spherical or has the shape of any   a body of revolution generated by a curved line, and in that the valve has a dimension such that, relative to the normal closing force of the valve, this valve   force makes it possible to obtain a plastic deformation of the   malleable by the seat, so that the form of   The general integrity of the flap and the seat is kept inde-   from any wear on the sealing surface of the valve.   6. Device according to claim 5,   characterized in that the sealing surface of the seat is   cunique and in that it is made of chrome alloy   cobalt harder than the valve body.