Bonded Seals

Fastener Seals

Description

A Fastener Seal is designed with a pre-calculated interference factor built into the teardrop shaped elastomeric seal. The cross section free height of the rubber is greater than the metal retainer, providing the proper compression without squeezing the seal beyond its elastic limit. As the fastener is installed into the mating hardware, the Fastener Seal is compressed down to the retainer thickness. The retainer provides a positive alternate load path for fastener torque and forms a protective gland area for the confinement of the seal in a controlled state. Since the elastomer seal cannot move outward, the mass of the seal is forced inward against the shank of the fastener and against the mating surfaces, creating a positive seal. This principle is known as controlled confinement sealing.

Thread Seals

Description

Thread Seals present a robust and efficient sealing solution for threaded connections, tailored to meet the precise demands of mechanical engineers. Characterized by their self-centering and non-directional design, these seals engage directly with thread contours, eliminating the need for specialized fasteners or fittings. This inherent design simplicity facilitates significant cost efficiencies by permitting the use of standard, readily available fastening components. Installation is straightforward and intuitive, requiring no specialized tools or training—simply affix the seal with a gentle twisting action and secure the fastener.

In their operational design, Thread Seals obstruct potential leakage paths within threaded assemblies. Typically positioned on the nut side of a fastener, they address the additional spiral leakage path presented by thread helices. The seal features three wedge-shaped internal protrusions, designed to interact with the singular V-shaped channel of standard screw threads, effectively blocking fluid migration.

Installation guidelines emphasize the importance of ensuring the rubber element is fully encompassed by adjacent metal components to prevent extrusion. The design necessitates a minimum flat surface area on the nut or washer to achieve this coverage. Additionally, since rubber cannot be compressed, it requires a designated void to accommodate displacement under load. This void is achieved through a clearance hole or, alternatively, a washer or counterbore to facilitate proper seating and performance of the seal. For applications involving adjustment screws, an NAS 20002 countersunk cover washer is recommended. While lubrication is not essential for the installation of Thread Seals, if used, compatibility with the selected elastomer is paramount.

Bonded Washers

Description

Originally developed as an advanced alternative to traditional copper washers in high-pressure environments, the 400 series bonded seal represents a significant innovation in sealing technology. This seal integrates a metal washer with an elastomeric ring securely bonded within its diameter. The design ingeniously combines the structural integrity of the metal washer, which acts to prevent over-compression, with the flexibility of the elastomeric ring, ensuring it remains within its optimal deformation limits. This synergy not only enhances the seal’s effectiveness but also its durability in demanding applications.