PATTERN RECOGNITION METHODS FOR TEXTURE ANALYSIS CASE STUDY: STEEL SURFACE CLASSIFICATION

A valve having a body with an inlet duct, an outlet duct and a plug rotatably disposed in the body. The plug has a port to provide for fluid communication between the inlet and outlet ducts and is movable between an open position wherein the port at least partially registers with both the inlet and outlet ducts to pass fluid through the valve to a closed position wherein no part of the port registers with the ducts, thereby preventing fluid from passing through the valve. The valve has a pressurizable seal between the body and plug, when the plug is at both the open and closed positions. To actuate the seal, a closed hydraulic system is provided. A regulator piston is urged against the pressure of the hydraulic system with a preselected force to regulate the hydraulic pressure. The valve also includes a mechanism to compensate for hydraulic fluid thermal expansion.