The sealing element makes up the interior of the oil seal, and the materials commonly used are:

For the housing stop installation technique, set the seal depth flush with the bore’s interior shoulder. This technique ensures that the seal is perfectly aligned with internal housing components. A depth gauge can be crucial here to confirm that the seal is positioned correctly.

THE DIFFERENCE BETWEEN MECHANICAL SEAL AND OIL SEAL

Before installing the oil seal, it is important to lubricate it to reduce friction and prevent damage during installation. A silicone-based lubricant is recommended for most applications. If the oil seal is to be installed in a high-temperature or high-pressure environment, a more specialized lubricant may be required.

Obtaining adequate adhesion of fluoroelastomer compounds to metal inserts is a major consideration in fabrication of shaft seals. Adhesive systems worked out for bisphenol-cured VDF/HFP/TFE elastomers often do not perform adequately for peroxide-curable fluoroelastomers and more base-resistant polymers that contain little or no VDF. The trend toward use of more resistant fluoroelastomers in shaft seals has necessitated considerable effort on compounding and adhesive system development to get adequate bonding of the new materials. Silane-type primers are often used to coat metal inserts; these contain residual active groups such as amine functions that interact with the fluoroelastomer compound to attain good adhesion, especially for VDF/HFP/TFE elastomers. Other adhesive systems, using epoxy compounds or tie-coats, may be necessary for difficult bonding situations.³

Introduction

This is one of the frequent reasons for oil seal failure, and this is majorly because of the volatility of any of the elastomer’s constituents. These causative constituents may be part of the elastomer formulation, or gases that got entrapped in the elastomer during the molding process. The deceiving fact about this failure is that sometimes the oil seal won’t show any visual sign of out-gassing, however, sometimes when the out-gassing is extreme, they shrink.