Effects of a Surface Engineered Metallic Coating on Elastomeric Valve Stem Seal Leakage (open access)

Effects of a Surface Engineered Metallic Coating on Elastomeric Valve Stem Seal Leakage

Valve stem seal leakage is a major source of fugitive emissions, and controlling these emissions can result in added expense in leak detection and repair programs. Elastomeric O-rings can be used as valve stem seals, and O-ring manufacturers recommend lubrication of elastomeric seals to prevent damage and to assure proper sealing. In this research, a metallic coating was applied as a lubricant using a vacuum vapor deposition process to the surface of elastomeric valve stem seals. Valve stem leak measurements were taken to determine if the coated O-rings, alone or with the recommended lubrication, reduced valve stem seal leakage. This research determined that the metallic coating did not reduce valve stem leakage.
Date: December 2000
Creator: Taylor, John Abner
System: The UNT Digital Library
Mist Characterization in Drilling 1018 Steel (open access)

Mist Characterization in Drilling 1018 Steel

Minimum quantity lubrication replaces the traditional method of flood cooling with small amounts of high-efficient lubrication. Limited studies have been performed to determine the characteristics of mist produced during MQL. This study investigated the mist concentration levels produced while drilling 1018 steel using a vegetable based lubricant. ANOVA was performed to determine whether speed and feed rates or their interactions have a significant effect on mist concentration levels and particle diameter. It was observed that the concentration levels obtained under all four speed and feed rate combinations studied exceeded the current OSHA and NIOSH standards.
Date: August 2012
Creator: Cole, Ian
System: The UNT Digital Library