... surface 3. Valve ball and seat materials: stainless steel and tungsten carbide4. 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, ...