Gate valve

Abstract

A gate valve comprising a valve housing with connection openings disposed in mutually opposite relationship on a first common axis, and also connection elements for the inlet and outlet of a fluid, a cap on the valve housing and a valve actuation means coupled to a sliding gate. It is provided therein that arranged in the valve housing are: a hollow cage having a first and a second end face of which the first end face has an insertion opening, further with two mutually oppositely disposed fixed side walls and two parallel mutually oppositely disposed free side walls which are formed by two separate side plates with through bores which in the installed condition are on a second common axis, the sliding gate which has a through-flow opening is introduced through the insertion opening of the cage and is guided sealingly in the cage and between the side plates and the side plates bear with their respective inward side in surface contact against the sliding gate, the sliding gate has two end positions so that in a first opened end position the through-flow opening of the sliding gate coincides completely with the diameter of the through bores of the side plates in the installed condition and in a second closed end position the through-flow opening of the sliding gate is completely outside the diameter of the through bores of the side plates.

1 . A gate valve comprising a valve housing with connection openings disposed in mutually opposite relationship on a first common axis, and also connection elements for the inlet and outlet of a fluid, a cap on the valve housing and a valve actuation means coupled to a sliding gate, wherein arranged in the valve housing are a hollow cage having a first and a second end face of which the first end face has an insertion opening, further with two mutually oppositely disposed fixed side walls and two parallel mutually oppositely disposed free side walls which are formed by two separate side plates with through bores which in the installed condition are on a second common axis, that the sliding gate which has a through-flow opening is introduced through the insertion opening of the cage and is guided sealingly in the cage and between the side plates and the side plates bear with their respective inward side in surface contact against the sliding gate, that the sliding gate has two end positions so that in a first opened end position the through-flow opening of the sliding gate coincides substantially or completely with the diameter of the through bores of the side plates in the installed condition and in a second closed end position the through-flow opening of the sliding gate is completely outside the diameter of the through bores of the side plates.  
   
   
       2 . A gate valve according to  claim 1  characterised in that the side plates and the sliding gate comprise ceramic and the mutually touching surfaces thereof are polished.  
   
   
       3 . A gate valve according to  claim 1 , wherein that the cage comprises a plastic material.  
   
   
       4 . A gate valve according to  claim 1 , wherein the valve housing, the connection elements and the cap comprise cast metal or are hot-pressed or forged.  
   
   
       5 . A gate valve according to  claim 1 , wherein the second end face of the cage has a cylindrical concave curvature and the curvature forms the connection of the fixed side walls.  
   
   
       6 . A gate valve according to  claim 5  wherein at one end, the side plates follow the contour of the curvature.  
   
   
       7 . A gate valve according to  claim 1 , wherein the separate side plates are inserted into the free side walls of the cage.  
   
   
       8 . A gate valve according to  claim 1 , wherein the side plates are of a mirror-image configuration and the first common axis of the mutually oppositely disposed connection openings, in the installed condition, coincides with the second common axis of the through bores in the separate side plates.  
   
   
       9 . A gate valve according to  claim 1 , wherein each separate side plate has a projection in the form of a rib which extends around the through bore and which engages into the connection openings of the valve housing or into the connection elements disposed therein.  
   
   
       10 . A gate valve according to  claim 1 , wherein the engagement of the separate side plates into the connection openings of the valve housing or into the connection elements disposed therein is sealed off by flat seals and/or O-rings.  
   
   
       11 . A gate valve according to  claim 1 , wherein the sliding gate has an abutment element for limiting the movement of the sliding gate.  
   
   
       12 . A gate valve according to  claim 11  wherein the abutment element is a transverse bar which is pushed through a transverse opening in the sliding gate and held there.  
   
   
       13 . A gate valve according to  claim 11  wherein transverse bar comprises cast metal or is hot-pressed or forged.  
   
   
       14 . A gate valve at least according to  claim 13  wherein the first opened end position of the sliding gate an abutment for the movement of the sliding gate is formed by a projection in the cap, against which projection the transverse bar bears, and in the second closed end position of the sliding gate a further abutment for the movement of the sliding gate is formed by the exposed upper face of the valve housing, against which the transverse bar bears.  
   
   
       15 . A gate valve at least according to  claim 13  wherein at the first opened end position of the sliding gate an abutment for the movement of the sliding gate is formed by abutment pins which are screwed into the transverse bar and which butt against the exposed upper face of the valve housing and in the second closed end position of the sliding gate a further abutment for the movement of the sliding gate is formed by a projection in the cap, against which projection the transverse bar bears.  
   
   
       16 . A gate valve at least according to  claim 15  wherein at least one of the side plates on the side that is towards the sliding gate has a passage which with its one end opens into the respective through bore in the side plate and which in the second closed end position of the sliding gate opens with its other end in the through-flow opening in the sliding gate.  
   
   
       17 . A gate valve at least according to  claim 1  wherein the valve actuation means has a spindle, wherein the spindle engages into the transverse bar and the sliding gate has a blind bore for receiving the spindle.  
   
   
       18 . A gate valve according to  claim 17  wherein the spindle is a screwthreaded spindle and is held axially immovably in a bearing in the cap and a screwthreaded portion of the spindle is screwed into the transverse bar.  
   
   
       19 . A gate valve according to  claim 1  wherein the gap between the spindle and the bearing in the cap is sealed off by an O-ring.