SAMPLE OF GAS PRESSURE AND PROCESS OF ITS MANUFACTURE Russian patent published in 1997 - IPC

FIELD: experimental equipment, technological processes of manufacture of fuel elements of nuclear reactors, determination of gas pressure in irradiated fuel elements of nuclear reactors placed into protective chamber or cooling pond. SUBSTANCE: sample of gas pressure is composed of cylindrical shell I with attached caps 2, 3 filled with gas under pressure. Body of cap 3 has through conduit 4 connected to shut-off device having screw 5 with sealing gasket 6. Cap 3 has elongated tubular part manufactured with possibility of conduit soldering with the use of resistance spot welding. Shut- off device is fabricated in the form of cylindrical body 8 having through axial 9 and radial 10 conduits. Sealing gasket 6 and screw 5 are set is sequence in axial conduit 9 from one butt of cylindrical body 8 joined with other butt to through conduit of cap 3. Gasket 6 interacts in this case with working part of screw 5 and radial conduit 10 communicates with atmosphere. Process of manufacture of gas sample consists in positioning of starting sample 24 having conduit for filling into working chamber II and in execution of procedure of its filling under constant control of value of gas pressure in working chamber II followed by subsequent sealing of sample. With formation of specified mixture of gases filling is conducted by turns with each gas component in the order when molecular mass of each following gas component is less than of the previous one and partial pressure of components of formed mixture of sample is found by results of measurement of values of gas pressure in working chamber in process of filling of sample by manometer 22. Mixing of components having considerably differing molecular masses is carried out directly in sample. Mixing of components having almost similar molecular masses is conducted in working chamber II. Sealing of sample is accomplished in two stages: first with the aid of shut-off device, then with the use of welding of conduit. EFFECT: increased reliability and improved metrological characteristics of sample of gas pressure. 3 cl, 2 dwg