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The Stanley SM21 Hydraulic Submersible Pump is a compact, high-performance solution designed for fast, reliable dewatering in confined spaces, utility vaults, manholes, and industrial environments. Built for durability and ease of use, the SM21 delivers powerful water movement in a lightweight, jobsite-ready design.
With its narrow profile and ability to operate without priming, the SM21 is ideal for professionals who need dependable performance in tight or hard-to-access locations.
High-Performance Dewatering
Delivers up to 300 GPM (1,135 LPM) at a 50-foot head, making it highly effective for removing water, sludge, and debris from trenches, vaults, and manholes.
Compact & Lightweight Design
At just 6¼ inches wide and weighing only 20 lbs. (9.1 kg), the SM21 easily fits through narrow openings and confined spaces while remaining easy to transport and deploy.
Durable Cast Iron Impeller
Equipped with a rugged cast iron impeller that resists abrasion and wear, ensuring long service life in demanding jobsite conditions.
Self-Priming & Fully Submersible
Requires no priming or suction hose, allowing for quick setup and immediate operation in any environment.
Maintenance-Free Operation
Minimal moving parts reduce maintenance requirements. The pump can safely run dry without damage, helping maximize uptime and productivity.
Wide Hydraulic Operating Range
Operates efficiently with a hydraulic flow range of 4–9 GPM (15–34 LPM) at 1,000–2,000 PSI, making it compatible with a variety of hydraulic power sources.
Maximum Capacity
300 GPM (1,135 LPM)
Discharge Size
2½-inch NPTF
Hydraulic Requirements
Flow Range: 4–9 GPM (15–34 LPM)
Operating Pressure: 1,000–2,000 PSI (70–140 Bar)
Dimensions
Length: 16 inches (40.6 cm)
Width: 6¼ inches (15.9 cm)
Connections
Porting: -6 SAE O-Ring
3/8-inch flush-face quick-disconnect couplers
Weight
20 lbs. (9.1 kg)


Utility & Construction Dewatering
Efficiently removes water from trenches, sumps, vaults, and excavation sites.
Manhole & Confined Space Pumping
Slim profile allows access to tight spaces where larger pumps cannot fit.
Industrial & Maintenance Cleaning
Handles sludge, slurry, and debris during industrial cleanup and maintenance operations.
Accessories


The Stanley SM21 stands out for its compact size, dependable performance, and low-maintenance design. Its ability to deliver high output in confined spaces makes it a trusted choice for utility crews, contractors, and industrial professionals who need reliable dewatering without unnecessary complexity.
Contact Intermountain Sales Inc. today to learn more about the Stanley SM21 Hydraulic Submersible Pump or to request a quote from your authorized Stanley Infrastructure distributor.
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