Production manner null of test tube for internal pressure fatigue test

摘要

PURPOSE:To prevent breakage and a leak from being caused at the joint part between a steel tube and a stopper plate by specifying screw pitch and screw thread height when engaging the screw of the stopper plate for pressure sealing with the screws of both tube ends of the steel pipe threadably and fixing them. CONSTITUTION:When the test tube 2 and stopper plate (pot lid) 1 for pressure sealing are fixed, the internal screw 14 and external screw 15 are formed according to JIS B0207 (meter fine thread), but the internal screw pitch is 0.5-1.0mm. Consequently, the minimum thickness of the thread-cut part is reduced to secure the strength of a screw part 13. Then the thread height of the internal screw 14 or external screw 15 is made 0.05-2.0mm larger than the standard of JIS B0207. Further, the screw part 13 is coated with an adhesive of epoxy two-liquid mixing type, etc., sufficiently and the screws are engaged. Consequently, the gap 16 between the screw top and bottom is eliminated to securely eliminate a leak in the joint part between the pot lid 1 and tube 2 at the time of a test.