External gear pumps represent a cornerstone of industrial hydraulic systems, delivering reliable positive displacement performance across demanding applications. Keister's external gear pump series combines precision engineering with robust construction, offering solutions for dumping trucks, lifting equipment, road construction machinery, and material handling systems where high pressure durability and volumetric efficiency are critical.
Our external gear pump lineup is engineered to meet diverse industrial requirements. The SGP series pumps feature advanced pressure-balanced plates and three-port design with DU bearings, delivering exceptional performance in lifting and road construction applications. For heavy-duty dumping truck operations, the KP series models utilize dual side-plate construction with cast iron bodies, ensuring maximum pressure resistance and extended service life in high-demand hydraulic systems.
Keister external gear pumps deliver superior volumetric efficiency through precision-machined meshing gears and optimized displacement configurations. The SGP1 and SGP2 models incorporate bi-metal side plates with ceramic-coated cast iron inlet bodies, achieving compact dimensions while maintaining low noise operation. Flow rates span from 3.2 to 75 cc/rev with pressure capabilities reaching 250 bar, suitable for handling lubricating oils, hydraulic fluids, and medium-viscosity industrial liquids. All units comply with ISO standards and feature pressure-balanced plate technology that extends bearing life while maintaining consistent performance across temperature variations.
High Pressure Durability: Dual side-plate construction with cast iron body design withstands continuous high-pressure operation in demanding dumping truck and construction equipment applications, significantly reducing maintenance frequency and operational downtime.
Integrated Control Solutions: Smart integration of control valves and check valves within the pump assembly eliminates additional components, simplifying hydraulic circuit design while improving system reliability and reducing installation complexity.
Extended Service Life: Advanced DU bearing systems combined with ceramic-coated components and aluminum alloy construction ensure exceptional wear resistance, with the SGP1 hoisting pump demonstrating over 5,000 hours of continuous operation in field testing.
Compact and Quiet Operation: Three-port design with optimized gear tooth profiles minimizes pulsation and noise levels below 70dB, while aluminum front and rear covers reduce overall weight by 30% compared to traditional cast iron constructions.
External gear pumps excel in fixed displacement applications requiring consistent flow delivery across varying pressure conditions. For dumping truck hydraulic systems operating at 180-250 bar, the KP series offers optimal pressure handling with minimal internal leakage. Road construction and sweeping machinery benefit from SGP series pumps that balance compact mounting footprints with high volumetric efficiency. When selecting between models, consider fluid viscosity ranges (10-500 cSt optimal), operating temperature extremes, and required flow rates to match pump displacement with system demands.
What distinguishes external gear pumps from internal gear pump designs?
External gear pumps feature two identical gears meshing externally, offering higher pressure capabilities and better suitability for high-viscosity fluids. Internal gear pumps use a smaller internal gear within a larger external gear, providing smoother flow with less pulsation but lower maximum pressure ratings.
What maintenance intervals are recommended for Keister external gear pumps?
Standard maintenance involves hydraulic fluid analysis every 500 hours and complete seal inspection at 2,000-hour intervals. The ceramic-coated construction significantly extends these intervals compared to conventional designs, with some installations achieving 5,000+ hours between major services.
Can these pumps handle chemically aggressive hydraulic fluids?
Keister external gear pumps are optimized for petroleum-based hydraulic oils and synthetic fluids with lubricity additives. For chemical transfer applications requiring corrosion resistance, consult our engineering team regarding specialized sealing materials and body coatings.
How do I calculate the required pump displacement for my application?
Pump displacement (cc/rev) equals required flow rate (L/min) divided by shaft speed (RPM), multiplied by 1000, then divided by volumetric efficiency (typically 0.90-0.95 for Keister pumps). For precise selection assistance, reference our C101 series specifications or contact our technical support team.
With decades of expertise in precision gear pump manufacturing, Keister delivers customized hydraulic solutions backed by comprehensive technical support. Whether you're specifying components for new equipment designs or sourcing replacement pumps for existing systems, our engineering team provides application analysis, performance optimization, and rapid prototype development. Contact us today to discuss your external gear pump requirements and receive detailed technical specifications tailored to your operational parameters.
