... . Pump designation: 1) RHAM: Stationary Heavy Wall Barrel, Top Anchor, Mechanic Seating, Rod Pump 2) RHBM: Stationary Heavy Wall Barrel, Bottom Anchor, Mechanic ... , Rod Pump 11) THM: Heavy Wall Barrel, Mechanic Seating, Tubing Pump 12) THC: Heavy Wall Barrel, Cup Seating, Tubing Pump API 11AX sucker rod pump ...