NL03L0C , T-104-O - Gate Valve - Bronze, Fire Protection, Outside Screw and Yoke The NIBCO bronze gate valve features a screw-over bonnet, female threaded ends and outside screw and yoke (OSandY) stem/bonnet construction. It is FM Approved and tested and listed by Underwriters Laboratories of the US and Canada (UL/ULC) to be used in automatic sprinkler systems as a control valve. Choose NIBCO gate valves for the most specified, versatile and economical valve option in commercial, mechanical, fire protection and industrial applications.