De Dietrich 300026031 sheet gasket

A sheet gasket of this type is a flat, cut sealing component used between flanged joints or mating surfaces in a boiler or burner assembly. Its function is to create a leak‑tight seal for water, gas, or flue gases, preventing loss of pressure and protecting downstream components from contamination or damage. Such gaskets are common at heat exchanger connections, burner head flanges, gas valve unions, and pump or valve bodies. Selection of a replacement sheet gasket is determined by three factors: the exact dimensions (inner and outer diameter, thickness) to match the flange or recess, the material composition appropriate for the medium and operating temperature (e.g., fibre for water, graphite for high‑temperature flue gas, rubber for low‑pressure air), and the pressure rating of the joint. A gasket that is too thick or too thin, or of an incompatible material, will not seal reliably and may cause leakage or joint failure. When replacing a sheet gasket, always clean the mating surfaces thoroughly to remove debris and old gasket residue. Check the flange faces for damage or warping. Use the correct torque pattern for the fasteners to achieve even compression without over‑tightening. For boiler and burner applications, verify that the gasket material is rated for the maximum medium temperature and, if in a gas train, for the gas type. When the part is listed by a manufacturer code only, confirm dimensions and material against the original gasket before ordering.