Understanding the Mechanics: How Viking's Internal Gear Pump Works
Viking pumps are well known for their performance and effectiveness, especially due to their internal gear pump design. This article delves into the workings of Viking’s gear pump, shedding light on how it operates through positive displacement. Additionally, we will discuss the materials utilised in Viking gear pumps, such as cast iron and stainless steel tailored for usage scenarios.

Internal Gear Pumps: A Straightforward Design with Impressive Performance

An internal gear pump belongs to the category of displacement pumps. This type employs rotating gears housed in a sealed chamber to generate a vacuum at the inlet side, drawing in fluid before expelling it from the discharge side. The simplicity of Viking’s internal gear pump design stands out prominently. It comprises two moving components:
  • Drive Gear (Rotor), an internally toothed gear.
  • Driven Gear (Idler Gear), a toothed gear with more teeth than the rotor, resulting in an offset arrangement between them.
A crescent-shaped element within the pump casing divides the inlet (suction) and outlet (discharge) openings. When the gears spin, they disengage, forming chambers that capture liquid along the way. Let’s dive deeper into the process of the pumping cycle.
  • Suction: The liquid enters the pump housing through the inlet port as the rotor and idler gear create a low-pressure zone, pulling liquid into the expanding cavity.
  • Trapping: The liquid is held within a crescent-shaped seal while the gears rotate, preventing it from flowing towards the inlet.
  • Displacement: As the gears continue to rotate, the trapped liquid is pushed through spaces, between gear teeth, and out through the discharge port.
  • Continuous Flow: With each rotation, a new liquid is pushed out, ensuring a controlled flow.

Viking’s internal gear pump design offers advantages:

  • Efficiency: The positive displacement design minimises internal leakage, resulting in excellent volumetric efficiency.
  • Self-Priming: The pump can generate suction to draw in liquids, making it self-priming in certain situations.
  • Versatility: Internal gear pumps can handle a range of viscosities, accommodating both thin fluids and thicker substances.
  • Durability: The design, with few moving parts, reduces wear and tear, extending its lifespan significantly.

Exploring the Enhanced Functions of Viking’s Internal Gear Pumps

While the components of Viking’s internal gear pump centre are on the rotor idler gear and crescent, there are features that improve its performance and meet specific application requirements. Let’s delve into some of these innovations:
  • Sealing Options: Standard Viking internal gear pumps are equipped with either packing or mechanical seals. Packing, a choice, uses compressible material to create a seal but needs periodic tweaking for optimal efficiency and may not be suitable for high-pressure settings. On the other hand, mechanical seals provide a durable and leak-resistant solution, perfect for challenging environments. Viking also offers sealing choices like O™ barrier seals that combine O rings with a barrier fluid to deliver superior performance in applications involving harsh chemicals or emissions control.
  • Flow Reversal: Viking internal gear pumps can be customised for directional flow capability. This feature allows the pump to manage situations where the flow direction requires reversal—an asset in processes such as product loading and unloading or fluid circulation systems.

Capacity Control: Viking Provides Internal Gear Pumps that Enable Adjustments to Flow Rates

These pumps commonly use a pressure relief valve or a bypass system to control the flow of liquid being discharged. This function is useful in situations where adjusting the flow rate is important.
  • Managing Viscosity: The internal spaces within the pump play a role in ensuring performance when dealing with different fluid viscosities. Viking provides pumps with clearances tailored to handle liquids of medium viscosity or high viscosity fluids effectively. For example, pumps designed for high-viscosity tasks may feature clearances to prevent excessive wear and tear.
  • Controlling Temperature: Viking internal gear pumps can be fitted with jackets or heating components for applications involving temperature fluids. Jackets enable heating or cooling of the pump housing to maintain the desired temperature. Heated versions are particularly beneficial when dealing with fluids that have viscosity at high temperatures.

Applications: Where Vikings Internal Gear Pump Excels

Viking internal gear pumps are widely used across industries due to their versatility and dependable performance. Here are some key examples:
  • Chemical Processing: The capability to handle viscosities and corrosive substances makes Viking pumps suitable for transferring chemicals, resins, and solvents.
  • In the food and beverage sector, stainless steel pumps have designs tailored to meet cleanliness standards, making them perfect for moving syrups, oils, and other food-safe substances.
  • For the petroleum industry, Viking pumps are adept at transferring oil, lubricants, and fuels thanks to their self-priming abilities and sturdy construction.
  • In power generation facilities, it’s essential to have pumps for transferring coolants, lubricants, and other fluids; this is where Viking pumps excel.
  • In manufacturing settings, these pumps play a role in various industrial processes that involve fluid transfer activities like paint circulation, printing tasks, and machine lubrication systems.

Viking Offers a Range of Internal Gear Pumps in Materials to Suit Applications

Cast iron gear pumps are an economical choice suitable for handling non-corrosive and low-abrasive fluids. These pumps are commonly used in settings for transferring oil, lubricants, and fuels. Stainless steel gear pumps are perfect for applications involving liquids or those requiring high hygiene standards. Viking provides a variety of stainless steel grades to meet needs. When it comes to selecting the Viking internal gear pump for your application, there are a few key factors to keep in mind:
  • Fluid Characteristics: It’s essential to consider the viscosity, corrosiveness, and compatibility of the fluid with the pump materials.
  • Flow Rate and Pressure Needs: Make sure to choose a pump that can handle the flow rate and pressure requirements.
  • Material Choices: For fluids that are not corrosive, cast iron is a cost option, whereas stainless steel is ideal for hygiene, corrosion resistance, or high temperature applications.
  • Sealing Options: Selecting the seal type based on pressure, temperature, and fluid properties is crucial.
  • Additional Features: If needed, look into features like flow reversal, capacity control mechanisms, or heating elements to suit your application requirements.
IDEX Corporation’s Fluid & Metering Technologies (FMT) division includes Viking Pump in its portfolio of quality internal gear pumps. They offer an array of Viking pumps and related products to cater to your needs effectively. Viking ensures support by providing available replacement parts known as Viking Spares. Using Viking Spares will help maintain performance and ensure continued reliability of your internal gear pump over time.


The internal gear pump from Viking is known for its sturdy construction, which provides reliable fluid transfer in different sectors. Its capacity to manage viscosities and materials such as cast iron and stainless steel makes Viking’s internal gear pump an option for many uses. With assistance from IDEX FMT and easy access to Viking Spares, you can trust your Viking internal gear pump to serve you well for a period of time.