The hollow D profile seals offer low closure force and easy installation for many static applications. Additionally, they offer a compressive force of a lower durometer material and physical property of a higher durometer material. Therefore, seals with hollow D cross sections can reduce bolt loading and the stress exertion on the mating flanges. Compressive force can be easily adjusted by changing the wall thickness of the profile without lowering the material hardness.

Hollow seal profiles are typically used when sealing in applications that have one or more of the following characteristics:
• Clearance gaps are present after assembly
• The gland cross section is more deep than narrow
• Radial interference (squeeze) is needed to assist the end product assembly process
• Low closure force is needed
• Seal cross section surface contact area maximization without overfill