Applications

Marine applications:

• Fresh and seawater cooling pumps

• Bilge and ballast pumps

• Fire-fighting

• General service pumps

• Transport of slightly aggressive liquids with low viscosity such
  as diesel and lubricating oils
  

Industrial and utility applications:

• Industry water circulation

• Cooling tower distribution

• Diesel transfer

• District heating

• District cooling

The DESMI NSL pump meets the requirements for:

• High efficiency

• Low NPSH values

• Easy installation/service

• Specific materials

• Compact design

• Standardised to modular design

• Outstanding hydraulic design performance

• Spacer-coupling options for easy maintenance

• Robust shaft design

• High efficiency impeller with low NPSH values

• Self-priming ability with a separate built-on priming pump

Technical Product Specifications

The design of the NSLV-R/NSLH-R pumps is for medium/high flow capacities up to 6,200 m³/h (27,300 US GPM) & medium head up to 200mLC. The pump may be configured as vertical or horizontally. Both versions are radially split, single stage centrifugal pumps with connecting flanges according to international standards. The design of the pump includes mounting with electric motors having different international flange dimensions.

Materials for pump casings can be grey cast iron (GG20) or ductile cast iron GGG40 EN1561-GJS-400 for fresh water. GGG40 pumps can manage working pressures up to 25 bar (i.e. 37.5 bar test pressure). For seawater applications, the pump construction of the casing may be NiAlBz EN1982 CC333G or Super Duplex 1.4410 (~SAF 2507).

The pump casing is equipped with a NiAlBz or Super Duplex replaceable sealing ring. Material of the shaft is high quality duplex stainless steel AISI329/1.4460 or Super Duplex.

The pump is fitted with dynamically balanced impellers acc. to ISO21940/1-2019G 6.3 (G2.5 or G1.0 are optional) that incorporates advanced double-curved blades to ensure low NPSHr values and high efficiency resulting in lower energy consumption and therefore lower running costs.

Standard impeller materials are NiAlBz or Super Duplex (e.g. for Scrubber applications).

The pump is fitted with a variable pitch inducer mounted on the pump shaft end in suction port to prevent cavitation bubble development on the impeller blades. With inducer the pump can be operated at a higher speed and/or in lower NPSHa applications than a pump without inducer. The inducer material is stainless steel AISI 316 (~1.4436) as standard.

The mechanical shaft seal is a single acting, mechanical shaft seal. The pump can be used for liquid temperatures up to 250°F/120°C. For liquid temperatures above 250°F/120°C a balanced shaft seal design is used.