Blog Details

internal gear pump

How Are Internal Gear Pumps Used Across Different Industries?

This blog explains the internal gear pump working principle, their industrial uses, and the key benefits of using them for smooth and reliable fluid handling. 

Smooth and reliable fluid transfer is important in many industries. From oils and chemicals to syrups and lubricants, industries need pumps that can handle a wide range of fluids without compromising performance. This is why internal gear pump applications and uses continue to grow across various industrial sectors. 

An internal gear pump is widely used due to its capability to efficiently pump thick and delicate fluids. Furthermore, its straightforward operation, minimum maintenance requirements, and dependable performance make it an ideal choice for prolonged use in industry applications. It is therefore essential that we familiarize ourselves with how the internal gear pump operates. 

 

What Is an Internal Gear Pump? 

An internal gear pump is a type of positive-displacement pump used for smooth and controlled fluid transfer. It uses two rotating gears to move fluid through the pump system at a steady flow rate. 

The internal gear pump’s working principle is simple and efficient. As the gears rotate, fluid enters the pump, moves between the gear teeth, and flows towards the discharge side under pressure. This helps maintain smooth fluid movement with minimal pulsation. 

Internal gear pumps are commonly used for handling: 

  • Oils 
  • Chemicals 
  • Lubricants 
  • Syrups 
  • Paints and resins 

Their ability to handle viscous fluids smoothly is one of the major reasons behind the growing internal gear pump applications and uses across industries. 

 

Internal Gear Pump Applications and Uses Across Industries 

Internal gear pumps are used in many industries because they provide smooth flow and reliable fluid handling. Their design makes them suitable for both low- and high-viscosity liquids. 

Industry  Common Applications 
Oil & Gas  Fuel transfer and lubrication systems 
Chemical Industry  Chemical and solvent handling 
Food Processing  Syrup, edible oil, and liquid transfer 
Paint Industry  Paint, resin, and coating transfer 
Pharmaceutical Industry  Smooth handling of sensitive fluids 
Power Plants  Oil circulation and lubrication systems  

These wide-ranging internal gear pump applications and uses make them an important part of many industrial operations. 

 

Advantages of Internal Gear Pumps in Industrial Applications 

There are many advantages of internal gear pumps in industrial applications, especially in industries that require smooth and reliable fluid handling. 

  • Effectively Handles High Viscosity Liquids 

Highly viscous liquids like oil, syrup, resin, and lubricants can be pumped easily by internal gear pumps without affecting the quality of flow. Thus, internal gear pumps can work in highly viscous materials’ processes. 

  • Smooth and Continuous Flow 

Gear pumps offer uniform fluid flow with low pulsations. Uniform flow ensures efficient system operation. 

  • Quiet Operation 

Internal gear pumps operate at lower noise levels than many other industrial pumps. This helps create a better working environment in continuous operation systems. 

  • Reduced Maintenance 

Their simple internal design helps reduce wear and tear during operation. This lowers maintenance needs and helps reduce downtime. 

  • Compact and Reliable Design 

Internal gear pumps are designed to fit easily into different industrial systems while maintaining reliable long-term performance. Their compact structure also makes installation easier in limited spaces. 

 

Factors to Consider Before Choosing an Internal Gear Pump 

Choosing the right pump helps improve efficiency and long-term performance. Before selecting a pump, a few important factors should always be considered. 

  • Fluid Type and Viscosity 

The type and viscosity of the fluid determine the suitability of the pump for the application. 

  • Pressure Requirement 

The pump should match the system’s required operating pressure. Incorrect pressure handling can affect performance and efficiency. 

  • Flow Capacity 

The pump needs to be able to handle the system’s required pressure to operate efficiently. 

  • Operating Conditions 

Temperature, environment, and operating hours should be considered for reliable long-term performance. 

 

Why Choosing the Right Pump Supplier Matters 

Picking the appropriate supplier of pumps is essential to ensuring seamless operation in industries and long-term efficiency. An ideal supplier does not just supply high-quality products but also assists industries in picking suitable pumps for certain tasks. 

Some important factors to consider include: 

  • Product Quality 

High-quality pumps help improve operational efficiency, reduce breakdowns, and support longer service life. 

  • Application Expertise 

An experienced supplier can recommend suitable pump systems based on fluid type, viscosity, and operating conditions. 

  • Long Term Reliability 

Reliable pumps help industries maintain stable performance and reduce maintenance-related issues over time. 

  • Industrial Support 

Proper technical guidance and service support are important for maintaining efficient operations and minimising downtime. 

Many industries also prefer working with trusted internal gear pumps manufacturers in India for reliable and efficient fluid handling solutions. 

 

Supporting Smooth and Reliable Industrial Operations 

The internal gear pump is one of the most vital pieces of equipment in industries where fluid transfer must be constant and effective. Its capability to handle thick fluids, provide smooth flow, and operate with low maintenance makes it suitable for many other applications. 

Understanding the internal gear pump’s working principle and selecting the right pump for application needs can improve operational efficiency and long-term reliability. The growing internal gear pump applications and uses across industries also show their importance in maintaining stable and dependable fluid handling systems. 

Among trusted internal gear pump manufacturers in India, Delta PD Pumps offers reliable positive displacement pumping solutions for various industrial applications. They have strong knowledge of industrial pumps, helping to move fluids smoothly and ensuring reliable long-term use. 

 

Frequently Asked Questions

An internal gear pump uses two gears of different sizes  smaller inner gear (pinion) that rotates inside a larger outer gear (rotor). Both gears turn in the same direction. As they unmesh on the inlet side, expanding cavities draw fluid in. A fixed crescent-shaped divider separates the suction and discharge zones. As the gears remesh on the discharge side, the cavity volume decreases and fluid is pushed out under steady pressure. This mechanism delivers smooth, near-pulsation-free flow particularly well-suited to viscous, shear-sensitive, and temperature-sensitive fluids.

Internal gear pumps are used across a broad range of industries precisely because they handle such a wide viscosity range. In petrochemical and oil & gas, they transfer crude oil, lube oils, bitumen, and heavy petroleum products. In chemical processing, they handle acids, polymers, resins, and solvents with material selection adjusted for chemical compatibility. In food and beverage, food-grade internal gear pumps move chocolate, syrups, edible oils, and dairy products with low shear and no contamination. In pharmaceuticals, they are used for sterile processes and viscous formulations. In marine and power generation, they serve fuel transfer and lube oil circulation duties. Their consistent, gentle flow makes them the default choice wherever product integrity or system reliability is non-negotiable. 

Internal gear pumps are effective across an exceptionally wide viscosity range from thin solvents under 1 cSt to highly viscous materials like bitumen, tar, and heavy polymers exceeding 100,000 cSt. Importantly, volumetric efficiency in an internal gear pump actually improves as viscosity increases, because thicker fluids reduce internal slip. This makes them well-suited to industries like asphalt, rubber, and polymer processing where other pump types struggle or become energy-inefficient. 

External gear pumps use two equal-sized gears meshing on the outside simpler and lower in cost, but better suited to moderate viscosities and higher pressures with clean fluids. Internal gear pumps use gears of different sizes, with the inner gear rotating inside the outer, offering quieter operation, better handling of high-viscosity and abrasive-sensitive fluids, and only one or two bearing surfaces in the fluid path (reducing wear risk). For industries dealing with viscous process fluids, chemically aggressive media, or food and pharmaceutical products, internal gear pumps are generally the more appropriate and durable choice.

Material selection depends on the fluid and operating environment. Cast iron is standard for oil, fuel, and non-corrosive industrial fluids. Stainless steel (SS 316) is used in chemical, food, and pharmaceutical applications for corrosion resistance and hygiene compliance. Bronze suits marine environments where galvanic corrosion is a concern. For extreme conditions high temperatures, highly abrasive fluids, or reactive chemicals specialised alloys such as Hastelloy or Inconel, along with coatings like PTFE or ceramic, are specified. Seal materials (Viton, PTFE, mechanical seals) are selected to match the specific fluid chemistry. 

Key factors include industry-specific experience (not just general industrial), the ability to supply in the right material of construction for your fluid, ISO 9001 certification, and local availability of spare parts particularly the crescent divider, gears, and seal assemblies. Manufacturers who provide performance test data at your operating viscosity and temperature (not just water-based factory tests) give you a more accurate picture of actual field performance. After-sales service capability and responsiveness are equally important for industries where pump downtime directly impacts production continuity. 

Yes, and this flexibility is one of the primary reasons internal gear pumps are favoured in multi-product facilities like refineries, chemical batch plants, and food processing units. By adjusting pump speed and selecting the right port configuration and seal type, the same pump model can often handle a range of viscosities across different process batches. However, it is important to verify that the pump’s NPSH requirements are met for the thinnest (lowest viscosity) fluid in the range, as lower viscosity increases the risk of cavitation at standard operating speeds. 

Leave A Comment

Download Pulm Oil
Download Pulse PDF Form
Download PDF Form

Message from Chairman Mr. Madhukumar H. Shah.

Since our inception in 1968, Delta has been committed to manufacturing high-quality Positive Displacement Pumps with a focus on reliability, engineering precision, and long service life. Our early collaborations with leading European manufacturers and our pioneering introduction of screw pumps in India laid the foundation for our technical strength.

Over the decades, we have continuously evolved by understanding the challenges faced by industries — from handling low-viscosity fluids to meeting higher pressure and reliability demands. With advanced metallurgy, precision screw profiles, and a dedicated team of experts, we strive to deliver not just pumps, but complete pumping solutions.

Pumps operating reliably for over 65 years stand as a testament to Delta’s commitment to engineering excellence and long-term performance.