GR55 SMT 250L SN RP T4 | Settima Screw Pump 250L/min 40bar

Product Overview

The GR55 SMT 250L SN RP T4 is a flagship model of the SETTIMA GR series three-screw pumps, belonging to the SMT16B series of standard dry-installation screw pumps. Founded in 1978, Settima Meccanica initially focused on producing high-technology three-screw pumps for the elevator industry to reduce noise and vibration in hydraulic circuits. Over more than four decades, Settima has become a globally recognized manufacturer of low-noise screw pumps.

GR series three-screw pumps are positive displacement rotary pumps that deliver media axially. The pump consists of one driving screw and two driven screws with specially profiled helical surfaces. As the screws rotate and mesh with each other, several sealed chambers are formed between the inlet and outlet, continuously transporting the media from the suction side to the discharge side. Key features include compact construction, smooth operation, extremely low noise, and pulse-free flow.

Model code GR55 SMT 250L SN RP T4 breakdown:

• GR55: Product series and size code – 55 indicates the model size in this series

• SMT: Standard Mounting Type (dry installation)

• 250L: Nominal flow of 250 L/min (@ 3000 rpm)

• SN: Screw configuration – suitable for high viscosity and air emulsion media, pressure up to 50 bar

• RP: Configuration version code (seal and port configuration)

• T4: Temperature grade code (special configuration)

We specialize in the R&D and manufacturing of high-pressure pumps, motors, and valve groups. The GR55 SMT 250L SN RP T4 offers 100% direct interchangeability with original Settima pumps of the same model—no modification required. Every unit undergoes 100% simulated load testing before shipment, ensuring performance validation under real-world operating conditions.

Technical Specifications 

Model & Series Information:

• Model: GR55 SMT 250L SN RP T4

• Brand Series: SETTIMA GR Series / SMT16B Series

• Pump Type: Three-screw pump

• Mounting Type: Dry installation (SMT)

Flow & Pressure Parameters:

• Nominal Flow: 250 L/min (@ 3000 rpm)

• Rated Flow (@ 1450 rpm): Approx. 120 L/min (proportional to nominal flow)

• Continuous Operating Pressure: 40 bar

• Peak Pressure: 50 bar

• SN Configuration Maximum Pressure: 50 bar

Speed & Drive Parameters:

• Speed Range: 500 – 3600 rpm

• Standard Drive: 4-pole motor (1450 rpm) or 2-pole motor (2950 rpm)

Materials & Construction:

• Pump Body Material: Extruded aluminum alloy (standard)

• Special Application Body: Cast iron, steel, hardened steel, stainless steel (on request)

• Driving Screw Material: C25 steel

• Driven Screws Material: Cast iron

• Seal Material: Standard FKM (Viton), optional NBR, EPDM

• Mounting Flange: ISO 3019/2 standard

Connections & Interfaces:

• Pipe Connections: SAE 3000 PSI or BSP threads

• Installation Position: Any orientation (SMT dry type)

Operating Conditions:

• Fluid Media: HLP mineral hydraulic oil (DIN 51524), biodegradable fluids, synthetic fluids, HFA/HFB/HFC/HFD

• Viscosity Range: 4 – 2000 cSt (standard), up to 10000 cSt (special configuration)

• Inlet Pressure Range: -0.7 bar to 3 bar (relative/absolute)

• Media Temperature: -20°C to +180°C (depending on seal material)

• Ambient Temperature: -20°C to +60°C

Filtration Requirements:

• Recommended Filtration: β25 ≥ 75

• Cleanliness Level: NAS 1638 Class 8 or ISO 4406 17/14

Noise Level:

• Acoustic Emissions: 52 – 68 dB(A) (@ 2950 rpm)

Note: Above specifications are based on standard configuration. Actual performance may vary depending on specific configuration codes (SN, RP, T4).

Key Technical Advantages

1. Ultra-Low Noise & Pulse-Free Operation via Three-Screw Principle

GR series three-screw pumps utilize three specially profiled helical screws (one driving screw + two driven screws) that mesh to create continuous, pulse-free media delivery. Compared to gear pumps and vane pumps, three-screw pumps operate with extremely low noise levels (typically 52–68 dB(A)) and completely pulse-free flow. Settima Continuum® series hydraulic screw pumps achieve noise levels of just 68 dB while delivering high-pressure power.

2. SN Configuration – Specifically Designed for High Viscosity & Air Emulsion Media

The SN screw configuration is the ideal choice for the GR series, suitable for high viscosity and air proportion media, with pressure capability up to 50 bar. This makes the GR55 SMT 250L SN RP T4 particularly well-suited for challenging media such as gearbox lubricating oils and air emulsions, delivering outstanding performance in lubrication systems.

3. Exceptional Reliability with Minimal Maintenance Requirements

Three-screw pumps have very few moving parts—only three screws and bearings—significantly reducing the probability of mechanical failure. The pump body is manufactured from extruded aluminum alloy, with the driving screw made of C25 steel and driven screws of cast iron, ensuring excellent wear resistance and fatigue strength. The SMT16B series requires virtually no maintenance, substantially reducing total lifecycle operating costs.

4. Broad Media Compatibility & Installation Flexibility

GR series can handle media ranging from mineral hydraulic oils to biodegradable fluids, synthetic fluids, water-glycol, phosphate esters, and more. Pumps can be installed in any orientation (SMT dry type) and can operate above oil level. ISO 3019/2 standard flanges and SAE/BSP port options ensure compatibility with a wide range of industrial equipment.

5. Excellent Self-Priming Capability & Wide Viscosity Adaptability

The three-screw pump design provides excellent self-priming capability, with inlet pressure as low as -0.7 bar gauge (0.7–3 bar absolute). From low-viscosity fluids at 4 cSt to high-viscosity lubricating oils at 10000 cSt, the GR series delivers stable performance across the entire spectrum.

Application Areas

• Gearbox Lubrication Systems—forced lubrication for various industrial gearboxes

• Turbine Lubrication Systems—bearing lubrication for steam and gas turbines

• Paper Machinery—bearing lubrication for calenders and dryer cylinders

• Compressors & Rotating Equipment—lubrication and cooling systems

• Mining Machinery—low-pressure hydraulic and lubrication systems

• Marine & Offshore—bearing lubrication and cooling systems

• Industrial Hydraulic Systems—low-pressure hydraulic circuits (up to 40 bar)

• Test Benches—hydraulic testing systems

Expert Maintenance Tips

Model Code Verification (verify each element):

Before installation, carefully verify the complete model code on the pump nameplate—GR55 SMT 250L SN RP T4—and confirm the following:

• GR55: Product series and size – 55 indicates the model size in this series.

• SMT: Standard Mounting Type (dry installation).

• 250L: Nominal flow of 250 L/min (@ 3000 rpm).

• SN: Screw configuration – suitable for high viscosity and air emulsion media, pressure up to 50 bar.

• RP: Configuration version code – seal and port configuration.

• T4: Temperature grade code – indicates special temperature configuration.

Verify Rotation Direction:

Standard GR series rotates clockwise when viewed from the shaft end. Before installation, confirm that the drive motor rotation matches the pump’s rotation requirement. Counter-clockwise rotation must be specified at the time of ordering. Incorrect rotation will prevent the pump from delivering media properly.

Suction Line & Inlet Pressure Requirements:

GR series screw pumps require a minimum inlet absolute pressure of 0.7 bar and a maximum of 3 bar. For GR55 and above running with 2-pole motors (approx. 2950 rpm), inlet pressure should be maintained at 0.5–3 bar. Ensure the suction line is properly sealed with no air leaks, and select suction line diameter appropriately based on flow rate to avoid cavitation.

Coupling Alignment & Installation Precautions:

Ensure that no axial or radial shaft loads are transmitted to the pump during installation. Use flexible couplings with concentricity within 0.05 mm. Mounting flanges conform to ISO 3019/2 standard. The pump can be installed in any orientation.

First-Start Priming Procedure:

After new pump installation or system overhaul, ensure the pump cavity is filled with media before first start. Jog the pump at low speed until the pump body is fully filled with oil and air is purged, then gradually increase to rated speed. Three-screw pumps must never be operated dry—running without media will cause severe wear to screws and the pump housing.

Filtration System & Oil Cleanliness Management:

Recommended filtration rating is β25 ≥ 75, with oil cleanliness meeting NAS 1638 Class 8 or ISO 4406 17/14. Regularly inspect return filter condition and replace hydraulic oil and filters per equipment manufacturer recommended intervals. Proper oil cleanliness management significantly extends pump service life.

Temperature & Viscosity Monitoring:

Maintain media temperature within the recommended range (-20°C to +180°C, depending on seal material). Excessive viscosity increases suction resistance, while low viscosity may reduce volumetric efficiency and increase internal leakage. Regularly inspect oil condition and replace if emulsified, degraded, or contaminated beyond acceptable limits.