Selection Guide for Elastic Teflon Straps

Thread Content

I. Gasket width (bD) 1. For convex and flat flanges, the gasket width shall be selected according to the following gasket coverage requirements: a. For EN or JIS standard flanges: 30–50% of the flange face width. b. ASME standard flanges: 50-75% of the flange face width. c. Non-standard flanges: Calculate the gasket width to ensure sufficient gasket stress. 2. For mortise-and-tenon flanges, a. the gasket should be able to cover the entire width of the groove surface. b. Ensure the tenon surface is slightly higher than the groove depth. 3. For the partition in the heat exchanger, a. The gasket width should cover the entire width of the partition. Note: The engineering torque should be estimated to ensure that the gasket stress is greater than the following values: 3 mm: 19 MPa (2,755 PSI); 6 mm: 23 MPa (3,335 PSI). II. Thickness selection: a. For most applications, a 3 mm thick strip gasket is required. b. For flanges with a deviation > 1 mm, it is recommended to use 6 mm strip gaskets. c. If the flange’s unevenness exceeds 2 mm, compensation shims must be used during installation; in such cases, consult the manufacturer’s engineer. III. Selection of installation stress: To achieve a reliable seal, sufficient gasket stress must be applied during the installation of the gasket. Typical minimum sealing stresses for SF100 and SF200: 3 mm: 19 MPa (2,755 PSI); 6 mm: 23 MPa (3,335 PSI). Perform engineering calculations to determine the torque value suitable for your specific application. Industry guidelines can be referred to, such as ASME PCC-1 Guidelines for Pressure Boundary Bolted Flange Joint Assembly and EN 1591-1 Flanges and their Joints – Design Rules for Gasketed Circular Flange Connections – Part 1: Calculation.