| 摘要 |
<p>PURPOSE:To provide a gasket which is excellent in heat resistance, chemical resistance, especially in alkali resistance, and excellent in recover of elasticity by providing projected parts in ring-like manner on the upper and lower sides of the circular-ring part of a porous polytetrafluoroethylene circular disc body, the central part of which is concentrically cut off, and permitting the density of the circular-ring part and the projected parts to be specified values. CONSTITUTION:On the upper and lower sides of a circular disc part 2 of a porous polytetrafluoroethylene circular disc body of specified thickness, the central part of which is concentrically cut off, projected parts 3 are provided concentrically with the circular disc body in a ring-like manner. The density of the circular-ring part 2 is taken as 1.0-1.9g/cm<3>, the density of the projected parts 3 is taken as 0.3-1.4g/cm<3>, and both the circular-ring part and the projected parts are integrally formed to form a gasket 1 for sanitary piping. The gasket is arranged and fitted in any fitting part of a sanitary piping system, the inside of which may be exposed to a damp or wet condition of alkaline solution and/or saturated steam, to closely connect the piping system. Thus, the sanitary piping system of production device, etc., for medicines, foods, etc., can be connected without leaking circulating materials in the system outside the system, and without contaminating the materials.</p> |
