CAT CLASS: HQ-10791

4-6 in Submersible Pump

The 4-6 in submersible pump class serves large sump and deep shaft dewatering applications where high flow and significant head are required. These pumps demand three-phase electrical feeds and lifting equipment for installation and retrieval. With discharge ports standardized at 4 inches and flow capacities from 455 to 900 gpm, this size bridges the gap between jobsite dewatering and municipal-scale pumping.

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Pick a size class — capacity and reach differ across the range.

Key specifications

Specification	Typical range	What it means
Discharge port diameter	4 in (10.2 cm)	Standard port size across this class, requiring 4-inch hose or piping.
Flow rate	455–900 gpm	Volume capacity suited to large excavations and continuous high-volume dewatering.
Max head	58–112 ft (17.7–34.1 m)	Vertical lift capability for deep shafts, sumps, and multi-story discharge.

How to choose

This size is appropriate when dewatering demands exceed 450 gpm or when lifting water more than 60 feet vertically from deep sumps or shafts. The three-phase power requirement and need for lifting equipment distinguish this class from lighter-duty applications. For flows under 400 gpm or where single-phase power is the only option, the 2-4 in Submersible Pump is the practical choice. When discharge exceeds 900 gpm or port sizes larger than 4 inches are specified, the 6+ in Submersible Pump becomes necessary.

What this size handles

Deep foundation excavation dewatering with high inflow rates
Multi-level shaft sump pumping in tunnel or mining operations
Emergency dewatering of flooded basements or parking structures
Large cofferdam dewatering where sustained high flow is required
Municipal pump station bypass during repairs or upgrades
Industrial sump applications with continuous high-volume discharge

Safety & operation

Lifting equipment must be used for installation and removal; manual handling risks injury due to weight
Electrical lockout/tagout procedures are essential before servicing; three-phase power presents serious shock hazards
Cable and discharge hose routing must prevent tripping hazards and protect against vehicle or equipment damage
Pump must remain fully submerged during operation to prevent motor overheating and seal failure

Transport & logistics

Weight and size typically require mechanical lifting or two-person handling; not portable by one operator
Transport via pickup truck bed or utility trailer; discharge hose and cable bundled separately
Lifting lugs or bail handles integrated for crane, hoist, or forklift deployment into deep sumps

Power & supply

Three-phase electrical service required; typical voltages range from 230V to 480V three-phase
Electrical cables are often 50 feet or longer to reach sumps and shafts; proper cable support and strain relief are critical
Motor protection and disconnect switches typically installed at surface level for safe shutoff

Frequently asked

What distinguishes this size from smaller submersible pumps?

The requirement for three-phase power, lifting equipment for deployment, and a 4-inch discharge port. Flow rates start where 2-4 inch models top out, and head capabilities support deeper sump applications.

Can these pumps handle solids or debris?

Model-specific; some units in this class are designed for clean water only, while others accommodate solids up to 2 inches. The application—clean sump water versus construction site runoff—dictates the impeller and volute design required.

How is the pump retrieved from a deep sump?

Lifting chains, cables, or integrated bail handles allow connection to a hoist, crane, or tripod. The electrical cable alone should never be used for lifting due to risk of damage and electrical hazard.