Diesel Gear Pump

Email: sales01@cxflowmeter.com

WhatsApp: 008618049841995

In response to the customer's gear pump + motor selection requirements, combined with the media, operating parameters, and the 

currently recommended solution (KCB83.3), the following detailed analysis focuses on technical compatibility, potential issues, and 

optimization suggestions, providing a more precise selection solution:

I. Technical Compatibility Analysis

Media and Viscosity

The customer's media are vacuum crude oil and diesel with viscosities of 12-20 cSt. The KCB83.3 covers this viscosity range, making it a

 perfect match.

Diesel viscosity decreases at 150°C (approximately 2-5 cSt), but the pump still covers the designed viscosity range without adjustment.

Temperature and Material

Operating temperature 150°C: The KCB83.3 pump head is made of cast iron, which has a temperature resistance of over 200°C, meeting 

the requirements.

If the media contains small amounts of sulfides or acidic components, upgrading to stainless steel (such as 304/316) is recommended for 

enhanced corrosion resistance.

Flow and Pressure

The customer's required flow rate is 36 L/min, while the KCB83.3's rated flow rate is 83.3 L/min, providing ample margin.

Optimization Suggestion: Use a frequency converter to reduce the motor speed to approximately 600 rpm (theoretical flow rate 

approximately 36 L/min), or install a bypass valve to adjust the flow rate.

The customer's required pressure is 4 bar (0.4 MPa), which is exactly the same as the KCB83.3's discharge pressure, eliminating the

 need for additional pressure boost.

Motor Parameters

Customer's motor: 440V, 60Hz, 1030 rpm, 1kW.

Pump Parameters: 440V, 60Hz, 1450 rpm, 2.2kW.

Speed Mismatch: The pump's rated speed (1450 rpm) is higher than the motor's speed (1030 rpm). Adjust the pump speed to 1030 rpm 

using the pulley or frequency converter. (At this point, the flow rate is approximately 60 L/min, still higher than required.) Insufficient 

Power: The pump's rated power (2.2kW) is significantly higher than the customer's motor power (1kW). Forced operation could result 

in motor overload and burnout.

Solution: Replace with a 2.2kW, 1450rpm motor, or select a lower-power pump model.

II. Potential Issues and Risks

Motor Overload

If the customer's 1kW motor is used directly to drive the KCB83.3, the pump's actual power demand may exceed the motor's rated 

power, causing overheating, burnout, and other problems.

Excessive Flow

The KCB83.3's flow rate is 2.3 times the required flow rate. If the flow rate is not adjusted, it may cause system pressure fluctuations

 or energy waste.

Speed Mismatch

The significant speed difference between the pump and motor requires an additional transmission, increasing cost and complexity.

III. Optimization Options

Solution 1: Adjust KCB83.3 Operating Parameters (Recommended)

Motor Upgrade: Replace with a 2.2kW, 1450rpm motor to directly match the pump's parameters. Flow Control: Reduce the speed to 

approximately 600 rpm (flow rate ≈ 36 L/min) using a frequency converter, or install a bypass valve.

Advantage: Maintains the high performance and reliability of the KCB83.3, suitable for long-term, high-load operation.

Option 2: Select a lower-flow pump model

Recommended model: KCB33.3

Flow rate: 33.3 L/min (close to customer requirements)

Pressure: 0.33 MPa (meets 4 bar requirements)

Power: 1.5 kW, 1450 rpm

Speed: 1450 rpm

Motor Compatibility: The customer's motor must be upgraded to 1.5 kW, 1450 rpm, or the existing motor can be used with a frequency

 converter to reduce speed (although flow rate may be lower).

Advantage: Lower cost, flow rate closer to requirements, and reduced regulation losses.

Option 3: Customized Pump-Motor Combination

Pump Model: KCB20 (20 L/min flow) or Custom Pump

If the customer allows a slightly lower flow rate, the KCB20 (20 L/min flow, 0.33 MPa pressure, 0.75 kW power) can be selected.

Or, the pump body dimensions can be customized to precisely match the 36 L/min flow rate.

Advantages: Perfectly matches requirements and offers optimal cost performance.

IV. Final Recommendation

Option 1 (KCB83.3 + 2.2 kW motor) is preferred for the following reasons:

Performance Redundancy: Sufficient flow and pressure margins are available to accommodate future demand changes.

High Reliability: The KCB series gear pumps have a mature structure, low failure rate, and are suitable for continuous industrial operation.

Flexible Adjustment: Flow and pressure can be easily adjusted via a frequency converter to meet varying operating conditions.

If the customer is cost-sensitive, Option 2 (KCB33.3 + 1.5 kW motor) is an option, but the customer must confirm whether the slightly 

lower flow rate is acceptable.

V. Additional Recommendations

Sealing Type: Diesel is volatile, so a mechanical seal + lip seal combination is recommended to reduce leakage risk.

Safety Valve: Install a safety valve at the pump outlet to prevent system overpressure.

Mounting Method: Horizontal installation facilitates maintenance and inspection.

For further information on pricing, delivery times, or technical details, please contact:

CIXIFM winny

Email: sales01@cxflowmeter.com

WhatsApp: 008618049841995