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Rule Industries 51S 1500 GPH Automatic Bilge Pump 12V with Anti-Airlock

Manufacturer

Rule Industries

<h3>Rule Industries: Five Decades of Marine Pumping Excellence</h3> <p>Since 1965, Rule Industries has been a trusted name in marine solutions, setting the industry standard with high-performance submersible bilge pumps. As part of Xylem's portfolio of water technology brands, Rule has built an exceptional reputation among commercial fishermen, recreational boaters, and marine professionals who demand equipment that performs when it matters most. As marine technology developed, Rule stayed ahead, delivering pump systems that became the go-to choice for commercial fishermen and recreational boaters alike.</p> <p>Every boat owner faces the same challenge: water intrusion is inevitable. Whether from rain, splash-over, or slow leaks, managing bilge water is critical to vessel safety and longevity. That's where Rule's engineering expertise becomes essential. Rule pumps have built their reputation in the field—through storms, mechanical failures, and those high-pressure situations where reliable water removal is the difference between a close call and a catastrophe.</p> <h3>Comprehensive Marine Water Management Solutions</h3> <p>Rule's product lineup centers on one core mission: keeping vessels dry and operational in any condition. Their <a href="/6623-rule-industries-electric-bilge-pumps-200350">electric bilge pumps</a> form the foundation of this commitment, offering flow rates from 360 GPH to over 3800 GPH to match any vessel size and water accumulation challenge. These pumps feature marine-grade construction designed to withstand salt spray, temperature extremes, and constant moisture exposure that would quickly destroy lesser equipment.</p> <p>Understanding that automation is key to peace of mind on the water, Rule offers multiple control solutions. Their <a href="/6623-rule-industries-float-switches-200426">float switches</a> provide reliable automatic activation when water levels rise, eliminating the need for constant monitoring. For comprehensive vessel protection, Rule's <a href="/6623-rule-industries-bilge-pump-switches-alarms-200163">bilge pump switches and alarms</a> deliver layered safety systems that alert operators to water intrusion while automatically managing removal. Rule Automatic Bilge Pumps feature built-in sensors that check for water every 2.5 minutes, ensuring continuous protection without manual intervention.</p> <p>Beyond bilge management, Rule provides specialized solutions for other marine applications. Their <a href="/6623-rule-industries-air-pumps-adaptors-200078">air pumps and adaptors</a> support livewell systems critical for fishing operations, while their extensive range of <a href="/6623-rule-industries-plumbing-parts-accessories-200786">plumbing parts and accessories</a> ensures that complete fluid management systems can be built, maintained, and upgraded using Rule components.</p> <h3>Engineering That Stands Up to Marine Environments</h3> <p>Rule's commitment to quality and durability makes their pumps the first choice among do-it-yourselfers and professional installers alike. The brand's pumps undergo rigorous testing to ensure they deliver rated flow rates even under challenging conditions. Their cartridge-style pump designs allow for easy maintenance—when debris clogs the strainer or impeller, the motor cartridge can be quickly removed for cleaning and reinstalled, minimizing downtime.</p> <p>High-quality materials handle salt spray, temperature swings, and constant moisture without breaking down, designed to keep working in conditions that destroy lesser equipment. This durability translates to real-world reliability for boaters who need equipment they can count on when far from shore, facing rough seas, or leaving their vessels unattended.</p> <h3>Why Marine Professionals Choose Rule</h3> <p>Rule's position in the marine industry reflects decades of proven performance. The brand's pumps are specified by boat manufacturers, recommended by marine technicians, and chosen by vessel owners who understand that bilge pump failure isn't just an inconvenience—it's a serious safety risk. From small recreational craft to larger commercial vessels, Rule provides scalable solutions backed by widespread availability through marine dealers and distributors worldwide.</p> <p>Whether you're replacing a worn pump, upgrading to automatic operation, or building a new vessel, Rule Industries delivers the marine pumping technology that keeps boats dry, protected, and ready for whatever conditions they encounter on the water.</p>

Part Number

51S
07/13/2036 5:06 AM
Sale Price

$206.80

In Stock (10+)

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Usually delivered within 2 days

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No Hassle Returns

No Hassle Returns

Live-in-stock inventory

Live-in-stock inventory

Fitment guaranteed

Fitment guaranteed

Product Details

The Rule Industries 51S is a 1500 GPH automatic electric bilge pump engineered for high-capacity, reliable bilge water management aboard marine vessels. Operating on 12 Volts DC, this pump features computerized automatic operation — no float switch required. The pump activates every 2.5 minutes to sense for water; if water is detected, it runs continuously until the bilge is clear, then resumes its monitoring cycle. In automatic check mode, it consumes only approximately 0.35–0.50 amp-hours per day, minimizing battery drain.

Designed to keep bilge water at the lowest level possible, the Rule 51S activates at just 5/8" of water and drains down to 1/4" — far more responsive than a standard float switch system, which typically allows water to reach 2" before activating. The 1-1/8" (28.6mm) discharge outlet accommodates standard marine bilge hose.

Key Features:

  • 1,500 GPH pumping capacity at open flow (12V DC)
  • Computerized automatic operation — no float switch required
  • 3-wire design allows manual override or indicator light capability
  • Double-insulated long stack motor for cooler, more efficient operation
  • Ignition protected — safe for use in gasoline-engine bilges
  • Fully submersible construction
  • No burn-out when run dry — safe if bilge runs empty
  • Moisture-tight PTFE seals for long-term reliability
  • Anti-airlock protection ensures reliable priming
  • Double strainer non-clogging protection with snap-lock strainer base for easy cleaning
  • Silent, vibrationless operation
  • Heavy 5/16" stainless steel shaft for durability
  • Nylon/fiberglass impeller for strength and corrosion resistance
  • Heat-resistant acetal resin housing
  • Marine-grade blocked wiring
  • Rust and corrosion protected
  • CE and ISO 8849 certified
  • 3-year limited warranty

Specifications:

  • Capacity: 1,500 GPH (open flow)
  • Voltage: 12V DC
  • Amperage: 4.8A
  • Discharge Outlet: 1-1/8" (28.6mm)
  • Operation: Fully Automatic (computerized sensing)
  • UPC: 042237084965

The Rule 51S is a trusted choice for boatbuilders and boaters worldwide, delivering proven bilge protection with minimal maintenance and long service life.

Products specifications

Amperage

4.8 Amps at 12 Volts DC

Capacity

1500 Gallons per Hour

Diameter

1 1/8"

Voltage

12 Volts

Warranty Details

Three Years Limited

Really easy !

Great experience. Fast shipping. Item arrived in good shape.

Customer service was nice and kind, still waiting on my return for my second product I purchased. The first purchase was perfect.

Product as advertised. Delivery as promised.

Easy and fast! Thanks!

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