| 摘要 |
PURPOSE:To obtain a quartz pipe having a metallic flange seal-bonded airtightly by melting by arranging cut glass pipes for reducing the gradient in coefft. of thermal expansion between a cut quartz pipe and a cut glass pipe for seal bonding to metal in the space between the pipes. CONSTITUTION:A plurality of cut glass pipes 4 having coeffts. of thermal expansion for gradually reducing the gradient in coefft. of thermal expansion between a cut quartz pipe 1 and a cut glass pipe 3 for seal bonding to metal seal-bonded by melting to a metallic pipe 2 for seal bonding to glass are interposed between the pipes 1, 3, and they are seal-bonded together by melting to form a flange A. A quartz pipe B is put in the flange A to a prescribed position at a uniform gap 5, and the end 6 of the pipe 1 is seal-bonded to the pipe B by melting. At this time, a heat resistant inorg. buffer 7 is inserted into the gap between the pipe B and the flange A to relieve an impact applied to the end 6 during seal bonding. The pipe B is a hollow pipe used as a protective pipe for a thermocouple, a solid pipe for an optical fiber, or the like. |
