Allweiler SN Series Three-Screw Pump

Name: Allweiler SN Series Three-Screw Pump – Datasheet & Quote
Brand: Allweiler
SKU: ALLWEILER-SN

Self-priming three-screw pump for oils and other lubricating liquids

The Allweiler SN series is a three-screw, self-priming screw pump used across industry wherever lubricating liquids are pumped that contain no abrasive components and do not chemically attack the pump materials. The datasheet lists a wide range of liquids: heating, lubricating and hydraulic oils, bitumen, greases, and chemical products such as polyols, isocyanates, paints, lacquers, adhesives, glycerin and resins, plus media such as paraffin, wax, syrup and pastes.

The main fields of application are oil-firing and power engineering, hydraulic, maritime and offshore engineering, machine tools, the chemical and petrochemical industries, the food industry and pulp and paper. Hardened and ground spindles rotate in a replaceable casing insert; the idler screws are driven hydraulically and axial thrust is fully compensated hydrostatically. Specially shaped thread flanks form sealed chambers, so the flow is virtually pulsation-free and no turbulence results.

Technical specifications

Data below is taken from the Allweiler SN series datasheet. Performance values assume drive speeds from three-phase motors on a 50 Hz grid, and binding limits are in the order documentation.

Parameter	Specification
Capacity	Up to 5300 l/min (3600 l/min standard; 5300 l/min in a special version)
Discharge pressure	Up to 64 bar (limit depends on casing material)
Inlet pressure	Up to 10 bar
Liquid temperature	Up to +150 deg C (depends on the seal)
Pump sizes	40, 80, 120, 210, 280, 440, 660, 940, 1300, 1700, 2200, 2900, 3600
Suction flange	Up to DN 150 per DIN EN 1092-2 PN 16 (pump casing branch up to DN 200, PN 10)
Discharge flange	PN 40 (casing EN-GJL-250) or PN 64 (casing EN-GJS-400-15) per DIN EN 1092-2; ANSI, SAE, JIS and BS flanges on request
Series and drive	SNH and SNGH direct drive; SNS and SNGS with motor bracket; SNF and SNGF with wall or foot mounted bracket
Shaft seal	Mechanical seal or shaft seal rings; return pipe from seal chamber to suction
Bearing versions	U internal bearing; D external lifetime-sealed; E external relubricable; Q and DQ without shaft seal
Heating options	Version E electric, X heating shell, P heating cartridge, Y double jacket (welded steel only)
Noise level	50 to 100 dBA depending on speed, size and installation
Explosion protection	ATEX 94/9/EC, device group II, category 2 G; temperature class depends on liquid temperature
Materials (pump casing)	EN-GJL-250, EN-GJS-400-15 or welded steel, depending on material code W1 to W22
Example performance (40 mm2/s, 1450 1/min, 5 bar)	Size 40-38 30.7 l/min at 0.42 kW; size 3600-46 3523 l/min at 39.3 kW

Reading the model code and choosing a size

The model code follows the pattern SN, construction type, size, drive screw type, pitch, pitch angle, bearing type, shaft seal, annex, casing heating and material code, for example SN H 40 E R 46 U 4 QM E – W1. The size number is the theoretical capacity in l/min at normal pitch, so size 440 relates to roughly 440 l/min theoretical delivery before slip. Use the performance tables in the datasheet at the working viscosity and pressure, then check NPSH: values are 3.0 m for most small sizes and rise to several metres on large sizes at 2900 1/min.

Pumps can be supplied with built-on pressure relief valves, and if they are ordered without one, overload protection must be provided in the controller or as a pipeline-mounted valve. Where a base plate, motor and coupling are supplied, guarding to the DIN standard cited in the datasheet is included.

Related pumps and points to confirm

For a smaller lubrication screw pump see the Allweiler TRILUB TRL V16-40R41 screw pump. Confirm the liquid viscosity, abrasive content, inlet pressure and any heating need before an RFQ, because the datasheet treats the limits as maximum values that may need reducing. See also the pump category.

Documents and quotation

The Allweiler SN series datasheet can be downloaded from this page. Seven Star LLC is an independent supplier in Muscat. Please send the pump nameplate or full model code, the liquid and viscosity, flow, pressure and drive details with your RFQ.

Allweiler TRILUB screw pumps

TRILUB is Allweiler's name for a family of three-screw pumps built for lubricating and hydraulic oil service. One driven screw meshes with two idler screws inside a liner and moves the oil axially with little pulsation, which suits lube oil circuits of turbines, compressors, gearboxes and diesel engines. The listed TRL V16-40R41 is a complete pump from this family. Buyers who search for Allweiler oil pumps are usually looking for this kind of unit, in the GCC as elsewhere.

Ordering Allweiler pumps and parts: what we need

Send the full type designation and the serial or order number from the nameplate. For a complete pump add the oil grade and viscosity, flow, discharge pressure, speed and motor data. For parts, name the item needed, such as the screw set, liner, mechanical seal or bearing.