RU2161747C2 - Check valve unit - Google Patents

Abstract

FIELD: gas, oil and chemical industries. SUBSTANCE: check valve unit includes shut-off member, seat, circular sealing member and fastener for securing the unit inside working pipe line. Seat is made in form of cylindrical threaded bush. Inner surface of working pipe line has threaded section on which threaded bush-seat and additional threaded bush are secured. Bevels are provided on end surfaces of threaded bushes facing each other. These bevels form circular cavity together with inner threaded surface of working pipe line. Circular sealing member is located in circular cavity. EFFECT: enhanced operational reliability of check valve. 1 dwg

Description

 The invention relates to valve engineering, in particular to valves and protective valves, and can find application in gas, oil, chemical and other industries.

 Known check valve made of thermoplastic plastic, installed inside the working pipeline (Japanese patent application N 60-32067, M. class. F 16 K 27/02). The valve-pipe connection is sealed by appropriate heat treatment of the valve body.

 A disadvantage of the known device is the unreliable operation of a plastic valve under conditions of high temperatures and pressures.

 The prototype of the claimed invention is a check valve assembly designed to be placed inside an existing pipeline (UK patent N 2045401, M. CL F 16 K 15/03).

 The check valve assembly contains a seat made in the form of a cylindrical sleeve mounted inside the pipeline. The inner diameter of the pipeline and the outer diameter of the sleeve are such that the sleeve has the ability to slide inside the pipeline. In the working position, the saddle is fixed in the pipeline from axial displacement with the help of annular locking elements located in the reciprocal radial annular grooves, respectively made on the inner surface of the pipeline and the outer surface of the cylindrical sleeve-saddle. Rotary valve flaps are fixed on the saddle. The seal of the saddle-pipe connection is carried out using an elastic ring element placed in an annular groove made in the saddle.

 The disadvantage of the prototype is the unreliability of the seal of the valve shutter in conditions of high pressure working environment.

 The claimed invention solves the problem of improving the reliability of the check valve.

 The problem is solved in the check valve assembly containing a seat made in the form of a cylindrical threaded sleeve, an additional threaded sleeve, a locking member and an annular sealing element. The threaded sleeve-saddle and the additional threaded sleeve are fixed on the threaded section made on the inner surface of the working pipeline. On the end surfaces of the threaded bushings facing each other, bevels are made, forming, together with the internal threaded surface of the working pipeline, an annular cavity for placement of an annular sealing element therein.

 The invention is illustrated in the drawing, which shows a check valve assembly in section.

 A threaded section 2 is made on the inner surface of the working pipeline 1, on which a threaded bushing-saddle 3 and an additional threaded bushing are fixed 4. On the saddle surface of the bushing 3, a locking member 5 is mounted, pressed against the saddle by a spring 6. On the end surfaces of the threaded bushings facing each other 3 and 4, bevels 7 and 8 are made, forming, together with the threaded surface 2 of the working pipeline 1, an annular cavity 9 of variable volume for placement of an annular sealing element 10 therein.

 When installing a non-return valve in the working pipeline, the threaded sleeve-saddle 3 is screwed into the threaded section 2 of the pipeline in a position that ensures the functioning of the valve, a sealing ring 10 is installed and an additional threaded sleeve 4 is screwed. At that, the sealing ring 10 is tapered surfaces 7 and 8 of the threaded bushings 3 and 4 tighten to the threaded surface 2 of the pipeline 1 and provide a tight connection of the check valve assembly and the pipeline 1 in any desired position. As necessary, the volume of the cavity 9 can be reduced by bringing the threaded sleeves 3 and 4 closer together and the tightness of the connection can be restored.

 After starting the pump (not shown in the drawing) in pipeline 1, a direct flow of the working medium occurs, coming through the central holes in the threaded bushings 4 and 3 under the locking member 5. Overcoming the force of the spring 6, the working flow biases the locking member 5 and opens the passage in the pipe 1 .

 After the pump stops, the flow in the pipeline stops and the pressure on both sides of the check valve is equalized. Under the action of the return force of the spring 6, the locking element 5 of the check valve sits on the seat 3, closing the passage in the pipeline.

 If a backflow occurs in the pipeline 1, the check valve 5 shut-off valve 5 blocks the flow of the pipe, while the threaded connection of the pipeline 1 and the sleeves 3 and 4 reliably holds the check valve in the required position, and the pressed-in sealing ring 10 reliably seals the threaded connection.

Claims (1)

 A check valve assembly comprising a seat, a locking member, an annular sealing element and means for fastening the assembly inside the working pipeline, characterized in that the saddle is made in the form of a cylindrical threaded sleeve, a threaded section is made on the inner surface of the working pipeline for fastening the threaded sleeve-saddle to it, and additional threaded bushings, bevels are made on the end surfaces of the threaded bushings facing each other, forming, together with the internal threaded surface of the working pipe water an annular cavity for placement of an annular sealing element therein.