... .full-open,three/four-arm seats 3.API DONGLI Valves&Seats:High performance valves and seats are available from DL with the following ... Valve and Seat,Three-arm Valve and Seat,Three-wing Valve,Four-wing Valve,Full-open Seat,Long-life Bonded Valve with Urethane.Wide ... or stainless steel valves and elastomer- valve seats. mud pump three-arm valve assy