Self-cleaning poppet valve for a core testing apparatus

Claim 1

A self-cleaning poppet-valve assembly for use with an automatic testing apparatus for measuring characteristics of a reservoir rock core sample under simulated in-situ conditions, comprising: a core transfer piston having upper and lower ends and an internal passageway, operatively extendable to axially move a core sample to a core sample holder and for applying an axial stress to said core sample; an internal inverted valve seat having an orifice formed in said internal passageway at the upper end of said core transfer piston; a poppet valve including a piston rod having upper and lower ends, a valve face formed at the upper end thereof and a piston flange at its lower end mounted within the internal passageway of said transfer piston, said poppet valve being operable to selectively move said valve face to a valve-seat contacting position to close said orifice and away from said valve seat to open said orifice; means for positively flushing away rock particles from the region around said valve seat and said valve face when said poppet valve moves to open said orifice; inner and outer gasket-retaining seats formed at the upper end of said transfer piston; a gasket-retaining washer; inner and outer gaskets positioned respectively between said inner and outer gasket seats and said gasket-retaining washer; and a perforated core-contacting end cap threadedly engaging externally, the upper end of said transfer piston, to secure said gasket-retaining washer and said inner and outer gaskets to the upper end of the transfer piston.