Venturi Blowers, Metal

ALLEGRO Metal Venturi Blower — Compressed Air-Powered Confined Space Ventilation

The ALLEGRO Metal Venturi Blower is a pneumatically powered ventilation unit designed for confined space applications in shipyard, industrial, manufacturing, and utility environments. It operates on compressed air or saturated steam, using high-velocity air through the cast aluminum inlet housing and nozzle jets to create a venturi (pulling) action that moves large volumes of air through the galvanized steel diffuser. With no fan or moving parts, the unit requires minimal maintenance and eliminates the need for protective grills. Available in five sizes — Extra Small through Extra Large — it is suited for contractors and safety professionals who need reliable, portable ventilation without an electrical power source.

Technical Specifications

Available Items

Unlike electric blowers, the ALLEGRO Metal Venturi Blower requires no electrical power source and has no fan or moving parts, making it inherently low-maintenance and suitable for use in hazardous locations where electrical equipment poses a risk. The integrated 6' static ground connection and single-piece cast aluminum housing set it apart from basic pneumatic alternatives by addressing both durability and safety in a single unit. The crow's foot inlet connection and multiple inlet ports provide flexible hookup to existing compressed air or steam infrastructure on the job site.

Key Features & Benefits

No Fan or Moving Parts

The venturi design moves air entirely through pneumatic action — compressed air or steam passes through the casting and out the nozzle jets, pulling large volumes of air through the unit. This eliminates mechanical wear components, reducing maintenance demands and downtime on the job site.

Single-Piece Cast Aluminum Inlet Housing

The one-piece cast aluminum construction provides a robust, lightweight inlet housing that resists damage from job site handling. Fewer seams and joints mean fewer potential failure points compared to multi-piece assemblies.

Galvanized Steel Diffuser

The sturdy galvanized steel diffuser is built to withstand the demanding conditions of industrial and shipyard environments. Galvanization provides corrosion resistance for extended service life even in humid or chemically active atmospheres.

Integrated Static Ground Connection

A 6' (1.8 m) static ground connection is attached directly to the inlet housing, making the unit ready for use in hazardous locations where static discharge could ignite flammable gases or vapors. This is a critical safety feature for confined space entry in refineries, tanks, and similar environments.

Lightweight and Portable

Convenient carry handles allow one-person transport to any location without additional equipment. Lightweight construction means contractors can quickly reposition the blower as work areas change throughout the job.

No Guards Required

Because there are no exposed rotating fan blades, protective grills are not required. This simplifies setup and reduces the number of components to manage on site.

Optional Ducting Attachment

Ducting can be attached to direct airflow precisely where it is needed, giving contractors flexibility to ventilate tanks, manholes, tunnels, and other confined spaces with varying access geometries.

Common Applications

Confined Space Entry Ventilation

Used to push or remove air from tanks, manholes, vaults, and vessels prior to worker entry, rapidly purging hazardous gases in compliance with OSHA confined space requirements.

Shipyard Operations

Provides ventilation in ship tanks and enclosed hull sections where electrical equipment may not be permitted and compressed air lines are readily available.

Industrial and Manufacturing Facilities

Ventilates hoppers, silos, storage bins, and process vessels during maintenance or inspection activities in plants where compressed air infrastructure is already in place.

Utility Work

Suitable for ventilating underground vaults, pipelines, and tunnels encountered in utility maintenance and construction operations.

Tank Purging

Designed to fit American Petroleum Institute (API) standard tanks, making it appropriate for rapidly removing gases from petroleum storage tanks prior to entry or hot work.

Compatible Materials

• Compressed air supply lines (up to 140 psi)
• Saturated steam lines (up to 140 psi)
• 1/2" pneumatic hose with crow's foot connection
• Optional flexible ducting (attached to diffuser outlet)

Product Documents

• ALLEGRO Ventilation Blowers Linecard

Frequently Asked Questions

Q: What is the maximum operating pressure for this Venturi Blower?
A: The ALLEGRO Metal Venturi Blower must be operated on air or steam lines limited to 140 psi maximum inlet pressure.

Q: What type of inlet connection does this blower use?
A: It uses a 1/2" hose with a crow's foot connection from the air supply source to the side inlet connection on the housing.

Q: Can this blower be used in hazardous locations?
A: Yes. The unit includes a 6' (1.8 m) static ground connection attached to the inlet housing, which is intended for use in hazardous locations where static discharge is a concern. Because it operates on compressed air or steam with no electric motor, it is suitable for environments where electrical blowers are not permitted.

Q: Does the Venturi Blower require protective guards or grills?
A: No. Because there are no exposed rotating fan blades or moving parts, protective grills are not required.

Q: Can ducting be attached to this blower?
A: Yes, ducting can optionally be attached to direct airflow into confined spaces such as tanks, manholes, or tunnels.

Q: Is this blower available in multiple sizes?
A: Yes. The Metal Venturi Blower line is available in five sizes: Extra Small (9518-03S), Small (9518-03), Medium (9518-06), Large (9518-08), and Extra Large (9518-10).