Horizontal or Vertical Inline Pump Design – Which One To Choose ?

We all know that centrifugal pumps are the most commonly used pumps on the market right now because they are highly efficient at transferring liquids over a wide range of flows and pressures. Normally, for industrial uses there are two basic types of inline centrifugal pumps.

  1. Horizontal
  2. Vertical

The primary difference between the both types is the shape and the position of the shaft. In a horizontal centrifugal pump, the shaft is normally in a horizontal position. It is sometimes overhung or placed between bearing design. While in case of a vertical pump is one whose shaft is in vertical position; it is always an overhang and of radial-split case type design. When it comes to making a choice between horizontal and vertical inline centrifugal pump, convenience is one factor that you need to keep in mind.

The following are the advantages and disadvantages of a horizontal and vertical design which will help you make your selection:

Horizontal Or Vertical Centrifugal Pump Design - Which One To Choose ?

Advantages of a horizontal centrifugal pump design:

  1. Easier to install and maintain because the internal parts like rotor are easily accessible.
  2. Can be directly coupled to electric motor, engine or turbine.
  3. For low suction pressure: you can opt for an overhung design.
  4. For high suction pressure: you can opt for in between-bearing design.
  5. You can get various nozzle configurations that match your external site piping like:
    1. end suction top discharge
    2. top suction top discharge
    3. side suction side discharge.
  6. It is suitable for almost all indoor applications due to its low headroom requirements

Disadvantages of horizontal design:

  1. Its applications become limited where the net pump suction head (NPSH) required exceeds the NPSH available.
  2. It requires an auxiliary booster pump.
  3. The maximum allowable operating temperature as well as working pressure are both generally much lower than that in a vertical inline pump.
  4. A bigger footprint is required for horizontal designs.

Advantages of a vertical centrifugal pump design:

  1. It requires a smaller footprint than that of horizontal pumps
  2. It is suitable for spaces where the ground surface area is restricted.
  3. With a vertical centrifugal pump, the NPSH available can be increased.
  4. Such pumps are suitable for higher temperature and high pressure fluids.

Disadvantages of vertical design:

  1. They require large headroom for installation and maintenance especially when it comes to multistage units or turbine pumps.
  2. Only when direct coupling with an electric motor is available, such pumps can be used. With types of drivers like engine or turbine are used, vertical centrifugal pumps will not be the perfect choice for your industry.
  3. Due to the overhang design, it becomes difficult to balance the hydraulic axial thrust especially while dealing with high suction pressures.
  4. A multistage vertical inline pump would normally requires expensive barrel and pit.
  5. It will be prone various issues in its mechanical seals when it has to pump liquids with high dissolved gases since they will accumulate at the top of the seal chamber or the stuffing box. Here venting is difficult and less effective.

All the above given points will surely help you choose the right pump based on your specific requirements. Thus, it becomes very important to make sure you understand the specifications and limitations of each type.

Hope you found this article useful!