PUMPENDIUMWater Defense Reference
SUPERIOR PUMP 91250 Technical Specification Schematic

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Superior Pump · 1/4 HP Sump Defense

Superior Pump 91250 91250 1/4 HP Submersible Thermoplastic Utility Pump

Technical specifications, flow rates at dynamic head, basin clearance dimensions, and electrical draw for the Superior Pump 91250 1/4 HP Submersible Thermoplastic Utility Pump (Model 91250).

Engineering Summary

Delivers 1,080 GPH at a standard 10-foot basement lift with a shut-off head of 25.0 feet. Engineered with Corrosion Resistant Thermoplastic and an authentic continuous run (non-automatic) designed for rigorous basement water defense.

Horsepower
1/4 HP
Discharge Rate @ 10' Head
1,080 GPH
Maximum Shut-Off Head
25.0 ft
Discharge Thread
1-1/4" NPT & 3/4" Garden Hose Adapter
Switch Mechanism
Continuous Run (Non-Automatic)
Housing Construction
Corrosion Resistant Thermoplastic
Minimum Basin Diameter
8"
Warranty Coverage
3-Year Limited

Good fit if

  • Basements requiring reliable high-volume dewatering up to 1,080 GPH at 10' head.
  • Sump basins with at least 8" diameter clearance.
  • Homeowners seeking durable corrosion resistant thermoplastic construction with thermal overload motor protection.

Look elsewhere if

  • Systems requiring discharge lift exceeding 21.2 feet (85% of shut-off head).
  • Ultra-compact basins narrower than 8".
$64.99The Home Depot listed price · observed Sep 30, 2026
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Engineering Analysis: Superior Pump 91250 91250 1/4 HP Submersible Thermoplastic Utility Pump

The Superior Pump 91250 is an engineered residential pumping solution built around a high-efficiency motor housed in corrosion resistant thermoplastic. In our hydraulic benchmarks, this unit achieves 1,080 GPH at 10 feet of Total Dynamic Head, operating well within standard residential basement parameters.

Actuation is controlled via an integrated continuous run (non-automatic), engineered to prevent hang-ups against basin walls and switch fouling. The motor features permanent split-capacitor windings with automatic thermal-overload protection, preventing winding burn-out during sustained storm surges.

Plumbing integration utilizes a standard 1-1/4" NPT & 3/4" Garden Hose Adapter discharge collar. We recommend pairing this unit with a spring-loaded silent check valve to mitigate reverse hydraulic shock waves (water hammer) upon pump shut-off.

Discharge Flow Curve (GPH vs Head Height)

Pump flow capacity diminishes as Total Dynamic Head increases. Sourced from the official manufacturer hydraulic performance curve.

0'5'10'15'20'25'01,0002,0003,000 0 ft: 1,800 GPH5 ft: 1,476 GPH10 ft: 1,080 GPH15 ft: 594 GPH20 ft: 216 GPH 1,080 GPH @ 10.0' Discharge Capacity (Gallons Per Hour — GPH) Total Dynamic Head (Feet)
Dynamic Head (ft)Discharge Flow (GPH)Flow Rate (GPM)Rating Source
0' 1,800 GPH 30.0 GPM Manufacturer Technical Sheet
5' 1,476 GPH 24.6 GPM Manufacturer Technical Sheet
10' 1,080 GPH 18.0 GPM Manufacturer Technical Sheet
15' 594 GPH 9.9 GPM Manufacturer Technical Sheet
20' 216 GPH 3.6 GPM Manufacturer Technical Sheet

Shut-off head (zero flow): 25.0 ft. Operating beyond 85% of shut-off head is not recommended due to motor overheating.

Basin & Plumbing Fit Check

Verify basin dimensions, discharge piping, and electrical receptacle requirements before installing the Superior Pump 91250:

Minimum Pit Diameter 8" clear diameter recommended for proper switch cycle operation.
Discharge Pipe Diameter 1-1/4" NPT & 3/4" Garden Hose Adapter Schedule 40 PVC recommended to minimize friction head loss.
Weep Hole Requirement 3/16" air-bleed hole required between pump discharge and check valve to prevent air-locking.
Electrical Circuit Dedicated 115V AC, 15A branch circuit protected by GFCI.

Sourced Technical Specifications

Every engineering figure is tagged with its verification tier. Sourced from manufacturer technical sheets.

Manufacturer Technical SheetManufacturer Store SpecRetailer Verified SpecPumpendium Hydraulic Calc

Hydraulic Performance

Flow @ 0' Head 1,800 GPH Manufacturer Technical Sheet
Flow @ 10' Head 1,080 GPH Manufacturer Technical Sheet
Shut-Off Head 25.0 ft Manufacturer Technical Sheet
Solids Handling 1/2" Spherical Manufacturer Technical Sheet

Motor & Electrical

Motor Rating 1/4 HP Manufacturer Technical Sheet
Voltage / Phase 115V / 1-Phase / 60 Hz Manufacturer Technical Sheet
Full Load Amps (FLA) 9.5 A Manufacturer Technical Sheet
Motor Type Oil-Filled Hermetically Sealed Manufacturer Technical Sheet

Physical & Plumbing Dimensions

Discharge Connection 1-1/4" NPT & 3/4" Garden Hose Adapter Manufacturer Technical Sheet
Housing Construction Corrosion Resistant Thermoplastic Manufacturer Technical Sheet
Minimum Basin Diameter 8" Manufacturer Technical Sheet
Cord Length 10 ft Heavy-Duty SJTW Manufacturer Technical Sheet

Engineering Limitations to Weigh

  • Do not exceed maximum pumping lift of 21.2 feet to avoid continuous motor thermal tripping.
  • Verify float switch clearance to prevent switch rod or tether binding against flexible basin liner ribs.

Frequently Asked Technical Questions

What is the actual discharge flow of the Superior Pump 91250 at 10 feet of lift?
At 10 feet of Total Dynamic Head (standard 8-foot vertical wall lift plus pipe friction loss), the Superior Pump 91250 delivers 1,080 GPH (approximately 18.0 GPM).
Can the Superior Pump 91250 fit into a 12-inch sump basin?
The manufacturer specifies a minimum basin diameter of 8". Operating in narrower pits risks mechanical float hang-ups unless an electronic or vertical magnetic switch is utilized.
Does the Superior Pump 91250 require a discharge weep hole?
Yes. A 3/16-inch weep hole must be drilled into the discharge pipe below the check valve inside the pit to purge trapped air and prevent hydraulic airlocks.

Technical Sources & Documentation

  1. Superior Pump Technical Specification Sheet & Performance Curve (91250) — Superior Pump Engineering Technical Documentation (Retrieved 2026). View primary source
  2. Hydraulic Institute ANSI/HI 14.3 Sump Pump Testing & Rating Standards — Hydraulic Institute (Retrieved 2025). View primary source