DESMI NSL vertical inline centrifugal spacer pumps
The design of the NSL pumps is for medium/high flow capacities up to 6,600 US GPM & medium head up to 150mLC. The pump must be configured as vertical (especially recommended where small overall ground floor is available reduces floor space requirement with 50%) & must be radially split, single stage centrifugal pump with connecting flanges according to international standards acc. to DIN, ANSI or JIS. Installation without alignment is required. The design of the pump needs to include mounting with electric motors having different international flange dimensions.
Material construction of the pump casings needs to be ductile cast iron GGG40 EN1561-GJL-400/DIN1693 for plain water, which shall be able to manage a working pressure of 16 bar (tested 1,5 x working pressure). For seawater applications, the pump construction of the casing shall be RG5 bronze EN1982 CC491K/DIN17656.
The pump casing shall be equipped with a NiAlBz EN1982 CC333G/DIN17656 replaceable sealing ring. Material of the shaft shall always be of high quality duplex stainless steel AISI329/1.4460. The pumps to be fitted with bearings at both top and bottom to give a robust construction, designed for trouble free continuous duty.
The pump needs to be fitted with dynamically balanced impellers acc. to ISO1940/1-1986 (E) G6.3 that incorporates advanced double-curved blades to ensure low NPSH-values and high efficiency resulting in lower energy consumption and therefore lower running costs.
The construction material of the impeller shall be NiAlBz EN1982 CC333G/DIN17656 (as standard) or duplex stainless steel AISI329/1.4460.
The seal type shall be a single acting, mechanical shaft seal, which seals off the liquid cavity at the motor shaft.
The pump needs to be equipped with a spacer coupling, which is a combined distance and flexible coupling between drive unit and electric motor. This makes it possible to remove the complete bearing housing with shaft, bearings, shaft seal and impeller – without dismantling the motor or pump from the piping. This represent significant advantages to the end user, who with this pump solution secures his installation trouble free maintenance with minimum down time.
DESMI have manufactured pumps for District Energy in bigger scale since 1950, has ISO 9000 certification – and own branches, distributing partners and service providers in most markets around the world. DESMI have key focus on energy efficient solutions (often up to 85%) with easy maintenance, low downtime and a long life cycle. DESMI’s location in Denmark, the country with most experience and latest technology within District Energy is a huge advantage for our company – as we are constantly dealing with leading consultants and utility /energy companies, helping us to raise our game even further.