Press-in-place seals are static face seals with rectangular cross sections and self-retaining features integrated into the O.D. and / or the I.D. of the seal profile. These press-in-place seals offer a wider contact surface as well as greater seal retention in the groove. The applications of press-in-place seals are seen the most in automotive and heavy duty mobile industries; however, the seals can be used in many static applications where the seals are located on the face of the gasket.
Challenges in sealing castings
In automotive and heavy duty mobile industries, hardware and components commonly have cast grooves which present a unique sealing challenge. Cast grooves usually have porosities on the metal surface due to the nature of the casting process. Melted metal with the tiny air bubbles inside is injected into the mold. When the metal hardens, the air bubbles become little holes which then turn into porosities when the outside of the metal components is machined or ground. These porosities create potential leak paths for fluid or dirt if the seal surface is not wide enough. The profile of the press-in-place seals has rectangular geometry, providing a maximum sealing contact area and compensating for porosity imperfections in the cast groove.
A customer was using a standard static face seal with a rectangular cross section to keep water from entering the components. The seal fit nicely inside the groove on the face of the component. However, when the assembler turned the component upside down to install it onto another component, the seal fell out. To quickly fix the problem, the customer used glue to keep the seal in place but this temporary solution was messy and unreliable.
The press-in-place seals proved to be an optimal solution to this problem because of their self-retaining characteristic. The retaining features such as ribs and nibs are designed directly into the profile and therefore create interference between the groove wall and the seal, resulting in maximum seal retention.
As a result, the customer needed no adhesives or mechanical fasteners for the seal installation process, avoiding the potential chemical hazard from glue and saving money on fasteners.
Finite element analysis
Parker’s Application Engineers have done a Finite Elements Analysis on the press-in-place seals to show how the interference retained the seal inside the groove. The shapes and sizes of the nibs can be customized to each specific application, and can be designed into the O.D. and / or the I.D. of the seal configuration.
Parker’s O-Ring Division (TechSeal) extrudes and precision cuts the press-in-place seals, offering tremendous design flexibility. More information on TechSeal’s extruded and cut press-in-place seals can be found on the “Press-in-Place Seals” bulletin (TSD 5434) which can be downloaded. Please consult with Parker TechSeal’s Application Engineers for the optimal seal design that meets your application’s specific requirements.