In the continuation of the investigation of the building and types of pumps, this post. The centrifugal pump has several characteristics and in this section, we will present the most important ones. Later on in this part we will give a more thorough description of the different pump types.
Characteristics of the centrifugal pump
The number of stages
Depending on the number of impellers in the pump, a centrifugal pump can be either a single-stage pump or a multistage pump.
The position of the pump shaft
Single-stage and multistage pumps come with horizontal or vertical pump shafts. These pumps are normally designated horizontal or vertical pumps.
Single-suction or double-suction impellers
Depending on the construction of the impeller, a pump can be fitted with either a single-suction impeller or a double suction impeller.
Coupling of stages
The pump stages can be arranged in two different ways: in series and in parallel, see figure 1.
Construction of the pump casing
We distinguish between two types of pump casing: Volute casing and return channel casing with guide vanes.
Most common end-suction and in-line pump types
- End-suction pump = The liquid runs directly into the impeller. Inlet and outlet have a 90° angle.
- In-line pump = The liquid runs directly through the pump in-line. The suction pipe and the discharge pipe are placed opposite one another and can be mounted directly in the piping system
- Split-case pump = Pump with an axially divided pump housing.
- Horizontal pump = Pump with a horizontal pump shaft.
- Vertical pump = Pump with a vertical pump shaft.
- Single-stage pump = Pump with a single impeller.
- Multistage pump = Pump with several series-coupled stages.
- Long-coupled pump = Pump connected to the motor by means of a flexible coupling. The motor and the pump have separate bearing constructions.
- Close-coupled pump = A pump connected to the motor by means of a rigid coupling.
