A.Y. McDonald 21000 Series L - 15 GPM 4 in No-Lead Brass Submersible Pump End

The 21000 Series L - 15 GPM pump end is the hydraulic end of Baker’s 21000 Series 4 in submersible pump, sold without the motor. It mounts on a NEMA 4 in Baker motor of the same horsepower, to build a new pump or rebuild one in the field.

Baker builds the stack with its captured stack design: sand notches in the diffusers keep sand moving through the pump. Each pump is individually tested after assembly and stamped with the tester’s mark.

This listing covers 1/2 to 5 HP (7 models), all with a 1 1/4 in NPT discharge.

• Check valve — acetal poppet and seal housing, Buna-N O-ring and stainless steel retention screw; threaded for easy installation or removal; working pressure 400 PSI.
• Discharge casting and motor bracket — no-lead brass alloy.
• Discharge bearing — rubber around the stainless steel shaft; self-lubricating, holds shaft alignment.
• Diffusers — polycarbonate, corrosion and abrasion resistant, built for sand handling.
• Impellers — glass bead acetal.
• Shaft — 7/16 in 300 series stainless steel, hex drive, each one measured for straightness.
• Shell — polished stainless steel, threaded at both ends for field service.
• Cable guard — stainless steel; angled top keeps the leads in place while the pump is lowered or raised.
• Motor coupling — stainless steel.
• Intake screen — non-corrosive.

One pump end per motor. Need more head later? Step up in horsepower within the L - 15 GPM class with the matching larger motor. Need more flow? Move to a higher flow class of the 21000 Series; every class uses the same 1 1/4 in NPT discharge, so the drop pipe connection stays the same.

Source: Pumps by Baker catalog (Sept 2025, rev 3/26), pp. 31-32.

Find your horsepower in the row, then read across. Total head is the lift from the pumping water level to the discharge, plus the pressure you want at the tank (2.31 ft for every PSI), plus friction in the drop pipe.

Total head in feet · curves end at 27.5–30 GPM

Read from the published curve in the Pumps by Baker catalog (Sept 2025, rev 3/26), p. 32, digitized and rounded down, at the flows nearest 20%, 50% and 75% of the curve’s 30 GPM end. 0 GPM is the printed shut-off. For the 1/2 HP (the curve reads 184 ft at zero flow against the printed 173 ft), the printed shut-off is shown. The last column is the last flow every curve reaches; the curve ends are named in the table title.

Output in GPM at 30 PSI (switch cut-in), by depth to water

Output in GPM at 50 PSI (switch cut-out), by depth to water

Output tables as printed in the Pumps by Baker catalog (Sept 2025, rev 3/26), pp. 31-32, at the 30 and 50 PSI rows. Riser-pipe friction is not included (manufacturer note): add it for long or small drop pipe. — marks a point A.Y. McDonald does not print for that horsepower.

Baker 4 in motor by horsepower (230V unless marked, ordered separately)

Best operating range: the published curve shades the most efficient operating range for each model; the catalog prints no figures for it. The curve is in the image gallery.

Source: Pumps by Baker catalog (Sept 2025, rev 3/26), pp. 23-24.