Sample valve

A process for directing a sample from a continuous flow of fluid to a sample container comprising;

• passing said continuous flow of fluid through a sample valve which contains a valve body, said valve body containing a primary flow path therethrough from an inlet end to an outlet end, a valve stem connected to said valve body and movable through said primary flow path, a valve seat located across said primary flow path and directly opposite said valve stem in said valve body, said valve seat containing a passage therethrough communicating with said primary flow path at a valve seat passage inlet and with a sample outlet passage separate from said primary flow path at a valve seat passage outlet, said valve stem comprising an upper valving portion for seating and unseating in said valve seat for controlling fluid flow through said valve seat passage, said valve stem further comprising a lower portion below said upper valving portion which is moveable through said primary flow path and said valve seat passage and containing a metering component and a cleaning component, said metering component including a gradual downstream taper to allow control of fluid flow volume through said valve seat passage when said metering component is placed at said valve seat passage inlet, said cleaning component being below said metering component and comprising a cut-away portion substantially narrower than said metering component to allow greater fluid flow from said primary flow path to effectively flush and remove accumulated solids from said valve seat passage when said cleaning component is placed at said valve passage inlet, said continuous flow of fluid passing through said primary flow path, removing a portion of said continuous fluid flow from said primary flow path and directing said removed portion through said sample outlet passage by unseating said upper valving portion from said valve seat and placing said metering component at said valve seat passage inlet, directing said removed portion from said sample outlet passage to a sample container, stopping said removed fluid flow from said primary flow path when a sufficient amount of removed fluid has been collected in said sample container by seating said upper valving portion in said valve seat, said valve body further including a purge fluid passage comprising a bore substantially wholly contained in said valve body and containing an inlet separate from said inlet of said primary flow path and a purge fluid outlet communicating with said sample outlet passage, purging said sample outlet passage with a purge fluid supplied from said purge fluid passage to remove fluid from said sample outlet passage when said upper valving portion is seated in said valve seat, and periodically placing said cleaning component at said valve seat passage inlet to flush accumulated solids through said valve seat passage.