Vertical Multistage Pumps Explained: How CDL, CDLF and CDM Pumps Work

A vertical multistage pump is a centrifugal pump in which several impellers are stacked on one shaft inside a single casing. Water leaves the first impeller, is guided to the second, and gains pressure at every stage. The result is high head from a compact, upright pump that needs very little floor space.

Why choose a vertical multistage pump?

• High pressure in a small footprint. Adding stages raises the head without making the pump wider.
• Smooth, quiet running. The in-line inlet and outlet and the vertical shaft keep vibration low.
• Easy piping. Suction and discharge sit on the same line, so the pump fits straight into a pipe run or a booster skid.
• Clean-water duty. Stainless steel wetted parts suit drinking water, process water and many mild chemical duties.

The CDL, CDLF and CDM families

In the CNP range, the CDL and CDLF series are the workhorse vertical multistage pumps for water supply, pressure boosting, washing and general industry. The CDM series covers medium flows. Each series is built in sizes from small flows of a few cubic metres per hour up to large industrial duties, and each size is offered with a different number of stages so that the head fits your system.

Model codes follow a pattern. In CDL32-40 the first number is the rated flow class and the second is the number of stages, so the pump can be matched closely to the duty point instead of being oversized.

Typical applications

• Pressure boosting for buildings, hotels and hospitals
• Reverse osmosis (RO) and water treatment plants
• Boiler feed and hot-water circulation (where the model allows)
• Washing, cleaning and irrigation systems
• Industrial process water and cooling

What we need to recommend a model

To choose the right size, send us the required flow rate (m³/h), the total head (m), the liquid and temperature, and the power supply (voltage and frequency). Our engineers will select a model whose curve passes through your duty point near its best efficiency, and send a datasheet with the performance curve.

Not sure where to start? Ask the assistant on this page: type your duty, for example 20 m3/h at 40 m, and it will list matching catalogue models. For a final selection and quotation, contact CNP Pump Global.