Dichtspalt

Dichtspalt is a term used in German engineering, architecture and manufacturing to describe the gap between two mating components that must be sealed to prevent the passage of fluids or gases. The word combines dicht (sealed or tight) and spalt (gap). In practice, the Dichtspalt is the clearance that is closed or compensated by a seal, gasket, or sealant. Design considerations include manufacturing tolerances, thermal expansion, and pressure loads, ensuring that the seal can deform or compress to achieve leak tightness. A too-large Dichtspalt increases the risk of leakage, while a too-small tolerance can hinder assembly or cause excessive compression.

In mechanical engineering, the Dichtspalt appears at joints, flanges, pistons, valve seats, and interface surfaces where sealing elements such as O-rings, flat gaskets, or lip seals are used. The choice of sealing element and the surface finish influence the effectiveness of the seal. In architecture and window construction, the term describes the gap that must be sealed against air and water infiltration, typically with joint sealants or insulating profiles. In high-pressure or high-temperature environments, tighter tolerances or specialized seals may be required to maintain leak-tight conditions.

Measurement and quality control often specify the permissible Dichtspalt under defined conditions, with leakage rate or backpressure as indicators of performance. The concept is closely related to tolerancing, surface finish, material elasticity, and the interaction between contact stress and seal deformation.