... ball and seat materials: stainless steel and tungsten carbide 4. Pump designation: 1) RHAM: Stationary Heavy Wall Barrel, Top Anchor ... , Mechanic Seating, Rod Pump 2) RHBM: Stationary Heavy Wall Barrel, Bottom Anchor, Mechanic ... Seating, Rod Pump 3) RHAC: Stationary Heavy Wall Barrel, Top Anchor, Cup ...