Valve for hydrate forming environments

摘要

Methods and apparatus for allowing the injection of hydrate inhibitors into a valve cavity without washing out the valve seals, generally comprising a valve having a sealing member, such as a gate or a ball, that provides for fluid communication between the valve cavity and the valve flowbore. One embodiment of a valve constructed in accordance with the present invention is an expanded gate valve comprising a valve body having a flowbore intersecting a valve cavity and a gate assembly disposed within said cavity. The gate assembly is a parallel expanding gate assembly having ported, juxtaposed members that are moveable into a sealing arrangement with upstream and downstream valve seats disposed about the flowbore. The gate assembly further comprises a flow path that enables direct fluid communication between the aligned ports and the valve cavity. This flow path enables hydrate inhibitors injected into the valve cavity to flow freely into the port and the flowbore without crossing the sealing faces of the gate assembly.