NT

Summary

Product identification

The ALLWEILER Series NT pumps are horizontal volute casing centrifugal pumps, designed according to DIN EN 733, with additional sizes meeting DIN ISO 9905 technical requirements. They are primarily single-stage, single-flow pumps with axial inlet.

Specific two-stage additional sizes include NT 2/32-200, 2/40-250, and 2/50-250. These two-stage designs achieve relatively small delivery flows at high delivery heads, good efficiencies, and low NPSH values, while maintaining outer dimensions corresponding to single-stage sizes per DIN 24255.

The pump abbreviation on the nameplate indicates:

• Series
• Delivery branch
• Impeller Rated diameter
• Hydraulics
• Impeller actual diameter
• Shaft sealing
• Material design

For two-stage additional pump sizes, the number of stages is placed with a slash in front of the delivery branch nominal width (e.g., NT 2/32-200/01), and the actual impeller diameter relates to the second stage.

Operating limits

• Performance Data:
  • Flow (Q): up to 2300 m³/h
  • Delivery head (H): up to 140 m
  • Temperature of the liquid pumped (t): up to 160 °C
  • Outer pressure (pd): up to 10/16 bar (dependent on material)
• Admissible Temperature (applies to water; may change for other fluids):
  • Stuffing box uncooled: 125 °C
  • Stuffing box cooled: 160 °C
  • Mechanical seal uncooled: 140 °C
• Admissible Internal Pump Pressure:
  • Design with stuffing box:
    • Bearing bracket sizes 228 and 360: ≤ 16 bar
    • Bearing bracket sizes 470, 530 and 585: ≤ 10 bar
  • Design with unbalanced mechanical seal:
    • All sizes, except two-stage additional sizes: ≤ 10 bar
    • Two-stage additional sizes: ≤ 16 bar
• Admissible Inlet Pressure (ps): Inlet pressure plus maximum delivery head must not exceed the admissible internal pump pressure.

Electrical

• Standard Motors: Surface-cooled, three-phase squirrel-cage motors, IM B3 type of construction, degree of protection IP 55 according to IEC standard, class F insulation. Performances and main dimensions according to DIN 42673.
• Drive Options: Diesel engine, explosion-proof motor, and further drive options are possible.

Mechanical / Hydraulic

• Design: Horizontal single-stage, single-flow volute casing centrifugal pumps with axial inlet. Volute casing with cast-on feet. Shaft bearing in a bearing bracket, which can be provided with a supporting foot (serial equipment for bearing bracket sizes 585 and 700; available on request for other sizes).
• Branch Positions and Flanges:
  • Suction branch: axial
  • Delivery branch: radially upwards
  • Flanges:
    • Up to DN 150: according to EN 1092-2 PN 16
    • DN 200 and above: according to EN 1092-2 PN 10
• Shaft Coupling and Safety Guarding: Safety guarding according to DIN EN 294 is supplied when the scope includes pump, base plate, and shaft coupling (according to DIN 740 with or without spacer element). Safety standards according to DIN EN 809 are met.
• Bearings:
  • For Series NT and CNT: Two grooved ball bearings according to DIN 625, grease-lubricated for the whole service life, bearing clearance C3.
  • For Series NT-H and CNT-H: Oily bath with constant oiler and indicator.
• Connections Provided:
  • A1: Filling (Note: Not provided with size 25-200; filling possible at M2)
  • B1: Draining
  • D1: Leakage drain
  • M2: Pressure gauge
  • Depending on shaft sealing type:
    • S1: External sealing of stuffing box
    • K1, K2: Cooling of shaft sealing
    • E3: Venting
• Base Plate: Standard: channel steel base plate.
• Materials (Applicable to all material designs W1-W5):
  • Volute casing: GG-25, GGG-40, ST.ST.
  • Impeller(s): GG-20, G-CUAL10NI, GGG-40, ST.ST.
  • Diffuser: GG-25, ST.ST.
  • Stage casing: GG-25, ST.ST.
  • Casing cover: GG-25, ST.ST.
  • Shaft: 1.4021, ST.ST.316
  • Bearing bracket: GG-25
• Modular System: The series construction uses a building-block principle, allowing for interchangeability of parts with identical numbers within a vertical column in the combination tables, which helps reduce spare parts stock.

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Disclaimer: This summary is based on extracted text and may miss figures, footnotes, or revisions present in the full OEM PDF. Contractual data must always match the specific OEM PDF revision used on the project.

Official datasheet (PDF)

Lenntech datasheet mirror