Inline Pumps

Inline pumps are space-saving centrifugal pumps that pump fluids in a straight line. This is why they are also referred to as inline pumps. They are ideal for pumping media in heating systems, air conditioning systems and numerous other industrial applications.
Learn more now what exactly an inline pump is, where they are used and get an overview of their properties and areas of application.


Technical Data & Characteristics:

  • Delivery rate:  up to 1,040 m³/h  (4,579 gpm)
  • Delivery height:  up to 105 m  (344 ft)
  • Pressure:  up to 16 bar  (232 psi)
  • Viscosity:  up to 250 cSt
  • Temperature:  -25 till 180 °C  (-13 till 356 °F)
  • pH-value:  2 – 14
  • Gases:  up to 5 %
  • Solids:  up to 1 %  (particle size depending on pump)
  • Installations:  horizontal, vertical
  • Submersion:  no
  • International Standards:  ISO, EN
  • Drives:  electro
Request now without obligation for your application!
request now
What is an Inline Pump? - Differences to other Centrifugal Pumps

Inline pumps are centrifugal pumps that have been specially developed for applications in which the pumped medium flows through a pipeline. In contrast to conventional centrifugal pumps, which pump the medium perpendicular to the inlet and outlet direction, inline pumps are designed so that the medium flows directly through the pump without changing direction.

With their space-saving design, inline pumps are particularly suitable for applications where a compact design is required or where space is limited. Typical applications can therefore be found in building services engineering: in larger air conditioning systems, heating systems and water circulation systems. However, inline pumps are also used for process applications in industry.

Inline pumps are particularly suitable for pumping clean or only slightly contaminated liquids. They tend to pump low-viscosity liquids up to 250 cSt and fibrous slurries up to a consistency of 1 %. The hydraulic design ensures efficient pumping with a low NPSHr over the entire pump range.

High efficiency and low energy consumption are typical of inline pumps. Especially in combination with a monoblock design, the inline design is compact, stable and reliable. This monobloc design eliminates the need for a bearing unit. The need for wear parts and maintenance is correspondingly low. An optimized shaft seal chamber and relief holes in the impeller can improve the conditions for the shaft seal and maximize its service life. The closed impeller of inline pumps is suitable for many different fluids, increasing standardization and further minimizing the need for spare parts.

Inline pumps are easy and quick to install in both vertical and horizontal positions and require only a small installation space. They are available in various sizes and performance levels to meet the requirements of different applications.

Working Principle of Inline Pumps

The inline pump is a special type of centrifugal pump in which the suction and discharge connections are located in a straight pipeline line. These pumps are integrated directly into the piping system, as their design allows both nozzles to be on the same axis and have the same nominal diameter. These characteristics make inline pumps particularly popular in building services, where a lack of space often limits the possible installation options.

The pumping principle of inline pumps basically corresponds to the function of all centrifugal pumps: they use centrifugal force to pump liquids. The medium enters the pump housing via the inlet, where a rotating impeller is located. The rotation of the impeller pushes the medium outwards, creating a vacuum and drawing in new medium. In this way, liquid is continuously transported through the pump.

Popular Types of Inline Pumps

Like other pumps, inline pumps are available as glanded and wet-rotor pumps. The choice depends on the application and the pumped liquid:

  • Glanded pumps have significantly higher efficiencies and are therefore preferred for high performance requirements and large flow rates. As the motor does not come into contact with the pumped medium in this design, glanded pumps are also suitable for aggressive media.
  • Glandless pumps, in which the rotor runs in a can with the liquid to be pumped, operate much more quietly. They are therefore particularly suitable for areas where a low noise level is required, for example in or close to living spaces. They are also a good choice for applications with low flow rates or where the pumped liquid must be completely sealed off from the atmosphere.

However, a distinction must also be made between the connection options:

  • Inline pumps with screw connections
  • Inline pumps with flange connections
Areas of Applications for Inline Pumps

Inline pumps are used in a variety of applications where reliable and efficient fluid delivery is required under the most space-saving conditions possible. A predestined area here is building technology, especially in the HVAC (heating, ventilation, air conditioning) sector, which is also known as HVAC. But also for service water supply systems, in swimming pool and marine systems, in industrial circulation systems and for general water supply.

As pumps for heating systems, inline pumps are used to circulate the heating water through the system and ensure even heat distribution. As HVAC pumps, they ensure that the hot water from the heating source reaches the radiators or underfloor heating systems.

The units also play a crucial role as pumps for air conditioning systems, where they pump the refrigerant through the system to ensure efficient cooling. Thanks to their space-saving design, they can be easily integrated into compact air conditioning systems.

In cooling circuits, for example in industrial processes or data centers, inline pumps are used as circulation pumps to transport the coolant through the systems and regulate the temperature to ensure an optimum operating temperature.

Inline pumps are also used in domestic water supply systems to pump drinking water through the pipes and ensure a constant water pressure. They ensure that there is always sufficient water available in residential and commercial buildings, for example for showers, toilets or other applications.

In general, inline pumps can be used for pumping all water-like and low-viscosity media. These include various types of refrigerants and coolants, liquid gases, some liquids containing gas, liquid hydrocarbons as well as acids and alkalis. Inline pumps can even be used for oils if the viscosity is not too high.

Inline pumps offer an efficient and space-saving solution for a wide range of applications in the HVAC sector and in industrial processes. Their design enables easy integration into piping systems, while their high efficiency and versatility ensure reliable fluid delivery. Whether in heating systems, air conditioning systems, cooling circuits or industrial water supply systems – inline pumps always play an important role when reliable and efficient pumping is required.

Would you like to find out more about inline pumps or discuss how inline pumps fit your application?
Feel free to contact us for more information or a non-binding review & consultation of your application!

Request now without obligation for a detailed review & quotation!
request now

other centrifugal pumps

Find your right industrial Pump fast and easily
start Selector
Come over and learn more about the pumps and innovations of the SPA pump manufacturers
visit now
Find your right industrial Pump fast and easily
start Selector
Come over and learn more about the pumps and innovations of the SPA pump manufacturers
visit now