Vent structure fabrication method

Abstract

A vent structure for reliable long term operation at high temperatures is fabricated by annealing a tubing of predetermined length and size, placing a predetermined number of strands of stabilized zirconium oxide yarn of predetermined diameter longitudinally into one end of the tubing a predetermined distance therein, flattening and coiling and pressing the end portion of the tubing containing the yarn at predetermined pressures, annealing the formed tubing, and installing a particulate filter in the undeformed (normally lower) portion of the tubing. For use in venting helium generating reactor control pins located under hot molten sodium, a vent assembly including the vent structure and providing an air lock between the outer molten sodium and the vent is affixed to the upper end of each control pin. This is a division of application Ser. No. 376,527, filed July 5, 1973, now U.S. Pat. No. 3,803,816.

Dependencies are inferred from the claim text.