S Series — UTEK-DELE Axial Fan Range

The S Series is the low-noise family of the medium-diameter range. Its sickle blade profile, with serrated teeth on part of the trailing edge, is shaped to keep airflow and static pressure up at low rotational speed, which is why these impellers are usually found on cooling towers and heat exchangers as well as engine cooling packs.

Models run from the 1Z at 378-725 mm and the 7XL at 250-1040 mm through the 7Z, S38Z and S4Z, all on the Z-3 hub. Blade counts from 3 to 16 allow the same hub interface to be used across a range of duties, and the recyclable moulded blades keep service weight down.

Model Range and Specifications

The 7Z model in the same family covers 560-922 mm with 5 to 16 blades and is listed on its own series page.

Blade Materials and Temperature Range

Blade material is selected from the working temperature and from the atmosphere around the impeller:

The conductive PAGAS option is supplied for equipment working in explosive-risk atmospheres such as dust or gas. It addresses the working environment of the blade; machine-level certification remains the responsibility of the equipment builder.

Hub Options

Blades are supplied with matched hub sets. The hub carries the blade loads and sets the shaft interface, so it is selected together with the blade count:

Typical Applications

This series is normally specified for the following duties:

• Low-noise ventilation where blade-passing noise is regulated

• Cooling towers and heat exchangers

• High airflow and static pressure at low rotational speed

• Dust and gas atmospheres where conductive blades are required

Specification Support

When a fan is being specified or replaced, the following points are confirmed before a blade set is released. They are the same checks used for OEM programs and for retrofit projects.

• Duty point: airflow and static pressure required at the working speed, taken from the cooling pack or ventilation requirement

• Installation: available diameter, shroud clearance, mounting pattern and the shaft interface of the existing hub

• Environment: maximum air temperature, dust or gas atmosphere, and whether static discharge has to be avoided

• Drive: available power, belt or direct drive, and whether the fan has to reverse in service

• Service: blade weight for handling during maintenance and spare-part availability across the machine fleet

Blade count, profile and material are then matched to those conditions in a fixed order: material first, then blade count, then hub family, with diameter confirmed against the shroud. Working in that sequence keeps the mechanical interface stable when the duty requirement changes later in the project, and it is why the same blade family can often stay in production while the cooling pack is revised.

Quality Assurance and Dynamic Balancing

Blades are balanced on a hand laser balancing machine before shipment, and the conductive PAGAS option is supplied for equipment working in explosive-risk atmospheres. That material choice addresses the working environment; machine-level certification remains with the equipment builder.

Customization and Series Overview

Blade count, blade profile, hub family and material can be customized for OEM programs, and existing fans can be reviewed when airflow, noise or durability has to be improved on a running machine. Where higher pressure rather than lower noise is the objective, the P Series adjustable blades use the same Z hub family and can often reuse the same shaft interface.

Related ranges: K Series big airflow fans | R4Z special blade fan | P Series adjustable fans | H Series small impellers.