What is the most reliable sealing method for hydraulic fittings?
Elastomeric. Metal to metal seals such as pipe threads on port connections and flared or flareless connections on tube/hose connections have been around for years. They work well at low to medium pressures but can leak after time due to a variety of reasons. Elastomeric seals such as SAE straight threads on port connections and O-Ring Face Seal or SAE flanges on tube/hose ends absorb vibration and compensate for minor surface imperfections which result in a better seal.
