... alloy steel AISI 4119 construction2.Heavy-duty valve design3.Deep carburized wear surfaces4.Heavy-duty ... Premium Cross-Arms Valve and Seat,Three-arm Valve and Seat,Three-wing Valve,Four-wing Valve,Full-open Seat, ... Long-life Bonded Valve with Urethane ... or stainless steel valves and elastomer- valve seats. mud pump three-arm ...