The Monarch MST & MSS Series are available in 5, 7, 10, 15, 20, 30, 50 and 85 GPM sizes and provide fresh water from 4" diameter drilled wells, for depths up to 970 feet. The 5-20 GPM MST models include an engineered thermoplastic discharge head and motor bracket to provide abrasion resistance, and hydrolytic stability. The 5-50 GPM MSS models include a stainless steel discharge head, motor bracket, screen, and cable guard to provide abrasion, and corrosion resistance.
Ideal for supplying freshwater to rural homes, farms and cabins from 4” diameter or larger wells.

Discharge Head - MST: Thermoplastic; MSS: Stainless Steel - Incorporates built -in hex fluted guide bearing design for alignment and sand handling capabilities. Left hand threaded with large wrenching surfaces - 1¼" NPT female outlet threads standard up to 20 GPM. 30, 50 and 85 GPM models have a 2" NPT discharge.
Check Valve - Internal anti-spin check valve with o-ring seal. Molded from engineered polymer. Built-in on sizes to 20 GPM.
Top Journal Bearing - Hex driven hard-sintered 300 Series stainless steel.
Stage Assemblies (Floating Stack Design):
Diffusers are precision molded from abrasion resistant reinforced polymer and fitted with 300 Series stainless steel flanged sleeve bearings to provide radial alignment and protection from upthrusting in every stage.
Impellers are molded from reinforced polymer and ultra-sonic welded. Each impeller can float within the diffuser to allow sand or debris to flow through the pump without lock-up or binding. Each impeller incorporates uniquely engineered thrust pads running on stainless steel to prevent failure when pumps are operated in upthrust conditions.
Stage Plate is molded from abrasion resistant engineered polymer.
Pump Shaft - Large 300 series stainless steel 7/16" hex for strength and positive impeller drive.
Coupling - Hard-sintered 300 Series stainless steel press fitted to pump shaft for improved alignment.
Pump Shell - High grade, heavy wall 300 Series stainless steel for excellent corrosion resistance. Left hand threaded at both ends to prevent loosening. Easily repairable in the field.
Motor Bracket - MST: Thermoplastic; MSS: Stainless Steel - Rigid and accurate alignment to Nema standard fitted motors.
Intake Screen - MST: Thermoplastic; MSS: Stainless Steel
Cable Guard - MST: Thermoplastic; MSS: Stainless Steel - Cable guard fits into motor bracket to assure smooth entry into well casing.
Hardware - All screws, washers and assembly nuts are 300 Series corrosion resistant stainless steel.
Motors - All Monarch pumps are powered by corrosion resistant stainless steel Franklin Electric 2 or 3 wire water-lubricated motors. Thermal overload and built-in lightning protection. UL778 recognized with Nema standard mounting dimensions. All motors are rated for continuous duty.