Corrosive Fume Exhaust Duct Systems

Corrosive process exhaust is not a commodity ductwork decision. In semiconductor fabrication and other high-tech manufacturing environments, exhaust systems must safely contain and convey aggressive chemical fumes while supporting reliable production, controlled installation and long-term facility performance.

Fab-Tech PermaShield™ is Exentec’s fully engineered, modular corrosive fume exhaust duct system. It combines the structural strength of stainless steel with a fluoropolymer barrier coating, engineered joints, airflow-control devices and adaptable connection options. The result is a coordinated duct solution designed to perform as part of the wider process-exhaust and abatement environment.

Exentec's corrosive exhaust duct products are delivered by Exential (part of Exentec). With nearly 40 years of proven service in demanding applications, Fab-Tech PermaShield™ combines the structural strength of stainless steel with a fluoropolymer barrier coating to support safe and reliable process exhaust management.

Why corrosive fume exhaust duct matters in critical environments

Corrosive and hazardous process fumes can place significant demands on conventional ventilation infrastructure. Chemical exposure, condensate, temperature, pressure, airflow conditions and installation quality can all affect system performance over time. When ductwork is not designed for the process environment, facilities may face corrosion, leakage risk, unplanned intervention, installation complexity and disruption to critical operations.

A purpose-designed corrosive fume exhaust duct system helps project teams manage these risks through coordinated material selection, engineered joining methods, fit-for-purpose airflow control and project-specific technical support. For operators, the goal is straightforward: safe containment and reliable conveyance of process exhaust without compromising facility performance.

Designed for semiconductor and high-tech manufacturing

In semiconductor manufacturing, process exhaust must support the safe removal of corrosive, toxic, condensable and otherwise hazardous by-products from production tools and SubFab environments. The duct system is one part of a wider exhaust-management chain that may include tool connections, vacuum equipment, monitoring, abatement, drainage, controls and facility exhaust infrastructure.

Exentec supports semiconductor projects with solutions designed around the full operating environment. Fab-Tech PermaShield™ helps provide the engineered conveyance layer between process equipment and downstream exhaust or abatement infrastructure, supporting safe, coordinated and predictable system delivery.

The same requirements apply in other demanding environments, including life sciences, research laboratories, electronics, battery manufacturing, solar, chemical processing, electroplating and wastewater applications. Wherever corrosive exhaust streams must be safely contained and transported, the system must be selected around the actual process conditions - not around a generic duct specification.

A fully engineered corrosive exhaust duct system

Fab-Tech PermaShield™ is designed as a complete modular system rather than a collection of unrelated duct components. Exentec helps customers select and configure the duct, fittings, joints, airflow-control devices and connections required for their application, installation environment and project schedule.

Coated stainless steel ductwork

The system combines a stainless steel exterior with a fluoropolymer barrier coating on the interior surface. This construction is designed to support the mechanical robustness required in demanding facility environments while helping protect the duct interior from corrosive process streams.

Material compatibility must always be reviewed against the actual chemicals, concentrations, temperatures, pressures and process conditions involved. Exentec can support this assessment with product-specific chemical-compatibility information covering more than 500 chemicals, together with engineering guidance for project-specific applications.

Joining systems for installation flexibility

Fab-Tech PermaShield™ duct accommodates fast and easy installation with its joint systems including EZ Clamp, cast ring and angle ring options. When you specify EZ for a system joint, companion angle rings with multiple fasteners are replaced with a single fastener and band style clamp. This joining system provides safe, reliable joints without sacrificing flexibility or integrity. The combination of half round backing rings and the unique angled clamp band provides excellent clamping force with the added benefit of ease of installation

• The EZ-Clamp system is FM 4922 approved and is ideal for tool hook-up and drain line use. Available for 2" (50.8 mm) - 14" (355.6 mm) diameter sizes
• Cast rings available for 4" (101.6 mm) - 14" (355.6 mm) diameter sizes
• SS Stainless steel angle rings available for 4" (101.6 mm) - 128" (3251.2 mm) diameter sizes
• BI Black iron angle rings available for 16" (406.4 mm) - 120" (3048 mm) diameter sizes

Fab-Tech PermaShield installations use half of the labor of FRP system installations, and unlike FRP and "glued" plastic systems, there is no need for grinding, sanding, prep work or the use of malodorous epoxies and heating blankets, which is especially important in cleanroom settings. Using the EZ-Clamp joining system can save an additional 40% labor over other PermaShield joining systems. EZ-Clamp duct and fittings have the ability to be field-modified (shortened, add nozzles or drain ports) and the stainless steel exterior will never need painting. 

Airflow control: dampers and blastgates

Exentec offers a broad range of standard coated and uncoated airflow-control devices, together with custom-engineered dampers and blastgates designed to meet project-specific airflow, balancing and isolation requirements.

Our comprehensive range of industrial dampers and blastgates for airflow balancing, isolation and process control, including AMCA-certified, round and rectangular configurations with manual, gear-driven, chainfall and motorized operation.

We also offer a wide variety of actuation products including manual, gear driven, electric or pneumatic actuators which can be pre-installed and tested to ensure the proper functioning, speed of operation, and proper preload against blade stops. When required, there are optional actuators which can be installed within stainless steel enclosures for use in outdoor and exterior corrosive environments. 
 

Adapters, connections and system accessories

Adapters, connection points and accessories are specified as part of the Fab-Tech PermaShield™ system to support connections to process tools, instrumentation, piping and facility services while enabling a coordinated installation approach.

Adapters are available for male or female NPT threaded pipe, KF flange pipe, and Swagelok® tubing. For example, the Swagelok® adapters transition from 2” PermaShield EZ duct to either 1/4”,3/8”, 1/2”, or 3/4” threaded tubing. In addition, adapters are available for the installation of Dwyer pitot tubes and sprinkler heads.

Cast rings are standard on 4” to 14” diameter duct sizes. Uniform size, enhanced bosses, and cast edges provide improved joint alignment, more efficient mechanical force, and more sanitary appearance. All 14” diameter and larger duct are manufactured with companion angle rings.

The Exential flange is a specialty 2” and 3” diameter tap for connection of 2” and 3” diameter PermaShield EZ™ duct as well as a wide variety of specialty adapters.

Safety, compliance and facility confidence

Exhaust duct performance must be considered in the context of the complete facility, including process hazards, fire strategy, equipment layout, maintenance access and applicable codes, standards and insurer requirements. Fab-Tech PermaShield™ has a long history of use in demanding corrosive-exhaust applications and is supported by current FM Approval under the revised FM 4922 standard. The system also incorporates PTFE gasket technology designed to support joint integrity throughout the duct network.

Exentec has achieved FM Approval for Fab-Tech PermaShield™ systems in large-diameter main and submain applications. Project teams should confirm the approved configuration, installation conditions and local code requirements with Exentec and the relevant project authorities before specification and installation.

From engineering and fabrication to installation support

Exentec’s approach goes beyond supplying duct sections. We support corrosive fume exhaust systems as part of the wider critical-manufacturing environment, with expertise that spans engineering, fabrication, system integration, installation support and commissioning coordination.

By considering ductwork alongside process conditions, abatement interfaces, airflow control, construction sequencing and future facility requirements, Exentec helps customers reduce interfaces and make more informed decisions from concept through operation.