Technical Specifications

Technical Specifications


The arrangement describes the installation of the bearings and the position of the motor element in fans.

Arrangement 1

This is perhaps the most common arrangement for industrial and other applications. It is available in SISW and usually belt driven. Two bearings are mounted on a pedestal and the wheel is overhung to one side.

Arrangement 3

A bearing is bracket mounted on each side of the housing .  or on axial fans, on each side of the wheel. This results in a compact unit.

Arrangement 4

In this arrangement, the wheel is directly mounted on the motor's shaft (& bearings). The fan itself does not have a shaft or bearings. This arrangement is more common in axial or smaller centrifugal fans where proportions allow the motor shaft to reach the wheel hub.

Arrangement 7

An arrangement 7 fan is an arrangement 3 fan with a motor base attached to the drive side. It is designed to be direct driven through a flexible coupling, with the motor (or turbine) mounted on the attached base. In that case, it eliminates the need for separate independent bearing pedestals which can simplify installation. Arrangement 7 is available in SISW and DIDW.

Arrangement 8

This arrangement is similar to an arrangement 1 fan. A smaller "outrigger" motor or turbine base is customer provided, or shipped attached to the bearing pedestal, for direct connection through a coupling.

Arrangement 9

This is an arrangement 1 belt driven fan with the motor mounted on the fan rather than on the "floor". 


It is the direction of discharge of the fan's air. The discharge of the fan's air is always important because this must be oriented towards the correct direction for the connection with the ducts.  The discharge and direction of rotation of a fan shall always be observed from the side of transmission of the fan.

Air discharge positions are numbered from 1 to 16. The orientations can be seen from the engine's side.

Axial fans shall be defined in accordance with the entrance ducts.The entrance or exit ducts are conveniently located so that they adjust to the straight pipe of the axial fan. The direction of the air flow shall be defined from the wheel towards the transmission or vice versa.


This has different meanings for the different manufacturers. The most usual meaning of the term "class" is the one that defines the limits of rpm. of the fan.  The classes are defined using roman numerals.

AMCA defines for the fan equipment market and certain types of wheels (backward and onward inclined blades, airfoil).  

Which class to use? The best reason to specify the class is to obtain a better duration for the fan chosen and, at the same time, that is free of problems. The tables LLORVESA are a guide to follow, where the limits of rpm. and kw. are shown.


General Duty Wheels

Llorvesa’s Airfoil D10 wheels feature airfoil blades continuously welded to a streamlined wheel cone and heavy steel backplate. The hollow blades have weep holes to prevent moisture build-up inside the blade. Airfoil wheels have true non-overloading horsepower characteristics, mechanical efficiency over 80% and a steep stable pressure curve, ideal for applications with pressure variations. Should actual system pressure reach 30% higher than the pressure anticipated, the Design 10A would still deliver 90% of the original design volume.

Llorvesa’s airfoil is not only the most energy efficient wheel type, it provides the quietest operation. Fans are rated for temperatures to 800° when used with a shaft cooler and shaft seal. 

IIndustrial and Heavy Duty Wheels

Pressure Air Fans

Llorvesa´s Design 2300 radial bladed wheel is available in single and double width designs in sizes from 20" to 100". Diameters are variable to 115% of nominal with wheel widths available from 40% to 115%. As a rule, wheel width dictates air volume while the diameter controls the pressure. By varying the width and diameter, overlapping performance envelopes are created and optimum efficiencies are realized. Llorvesa’s Design 4900 radial bladed wheels available in single width sizes from 34" to 100". The wheel’s narrow width blades and slightly conical sideplate make it our lowest specific speed custom fan. Standard wheels are constructed from ASTM A606, A242 and A588 alloy steel capable of 800°F. Optional stainless steel wheels are rated to 1000°F. All PA fan wheels are dynamically balanced. The pressure range extends to 108" wg and volumes to 440,000 CFM.

Radial Tips

Industrial Fans with radial tip wheels are designed for handling dusty, dirty airstreams while providing excellent operating efficiencies. To maintain optimum performances over a wide range of volume and pressure, different wheel designs are needed. To fulfil this need Llorvesa RT Radial Tip fans are offered in a family of five wheel designs with overlapping performance envelopes.

In general, the width of the wheel dictates the volume of air while the diameter controls the pressure. With wheels design progressing from small diameters with wide blades to large diameters with narrow blades. Llorvesa can confidently supply the perfectly sized, highly efficient radial tip fan for every duty. 

Contact address

Carretera CV 703 , Km. 1
03820 Alcudia de Cocentaina (Alicante) · España
Phone number: 965 590 612

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