The Mathena™ hydraulic drilling choke ensures positive metal-to-metal closure, and is rated for ASME class 150 to 2,500. All major wear parts are made of heavy duty tungsten carbide for greater life and a streamlined vane provides minimum resistance to flow with no seating torque.The rugged control console uses high-pressure stainless steel tubing, ensuring safe operation and precise, remote control of choices. A conventional gland housing provides uniform support to packing rings while inboard bearing offer maximum support at the closest vane point.