A strainer for preventing debris from entering a turbine. The strainer comprises a casing having an inlet conduit for introducing a flow medium into said strainer and an outlet conduit extending substantially perpendicular to said inlet conduit for expelling said flow medium, said outlet conduit having conically expanding interior side walls; an annular seal affixed to said casing between said inlet and outlet conduits for forming a seal between said inlet and outlet conduits; a bonnet attached to said casing, said bonnet having an upper bonnet section affixed to said casing and hollow cylindrical lower bonnet cage which mates with said annular seat, said hollow cylindrical lower bonnet cage opening into said outlet conduit and having a plurality of apertures so as to permit flow into said hollow cavity and out said outlet conduit and strainer screen means surrounding said hollow cylindrical lower bonnet, said screen means preventing debris from entering said apertures.