AMERICA’s Sheet Metal Source

Since 1981

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Industrial / Specialty Duct

Ductwork has a lot of uses besides air conditioning. As "America’s Sheet Metal Source", Spiral Pipe of Texas has been manufacturing a wide variety of air transport systems since 1981.

We fabricate for a variety of applications — from cleanroom and pharmaceutical quality stainless steel exhausts through the big, tough and dirty ducts you’ll see in manufacturing, agriculture and mining.

If it’s metal and transports air, we are your source.

Stacks & Headers

Industrial Duct Products - Spiral Pipe of Texas

Industrial, fume and process exhaust ductwork has been a major part of our business at Spiral Pipe of Texas since our start. As our reputation for quality has grown, so have the sizes and complexities of some of the products we fabricate. We fabricate rolled and welded products from 22 gauge to 5/8” thickness and with diameters in excess of 100”.

Coupled with our traditional spiral-seam and longitudinal seam HVAC products, we have the capability of being your single source for a complete duct system.

Industrial Duct Products - Spiral Pipe of Texas


We have the capability to produce a large range of stacks — from small Weather Caps and Vertical Stackheads to large freestanding stacks in excess of 100 feet tall. Our design staff will work with you to produce the stack you need.

Our resources include the ACGIH Industrial Ventilation Manual, the SMACNA Guyed Steel Stacks and Guide for Free Standing Steel Stack Construction Manuals and the AWS D9.1M/D9.1 Sheet Metal Welding Code. We can also work with you to fabricate custom-engineered stacks.


Industrial Duct Products - Spiral Pipe of Texas
Industrial Duct Products - Spiral Pipe of Texas

Best practice for laboratory exhaust is no longer considered to be “one hood, one fan, one stack”. The EPA and Department of Energy now recommend fume dilution and the use of constant-volume high-plume exhaust fans. That has led to a growth in our manufacturing of large manifolded exhaust headers.

Since these sit on the rooftops, our customers often want these as a single assembly that can be crane-lifted and set in place. If it can fit on a truck, we can make it for you. Even if multiple sections are required, we can verify fit-up at our plant so you can assemble your maximum manifold on the project site.

Final Finish

We have the capability of producing stacks and headers from a variety of materials — galvanized steels, black iron, aluminum and stainless steels. But since stacks and headers operate in the outdoors, and often in caustic environments, sometimes a little more protection is needed. We offer additional services to complete the product — hot-dipped galvanizing, painting and industrial coating. Contact our Estimating Department for pricing and details of our stack and header products.

SPOT AgION Antimicrobial Coated Ductwork

Quality from Start to Finish

Indoor air quality has become a leading environmental issue. Studies have shown that the air we breathe indoors is often more polluted than outdoor air and that 70 or more percent of indoor air quality problems involve HVAC systems. Ductwork manufactured with AgION™ antimicrobial-coated steel helps resolve these contamination issues by providing a second line of defense against destructive microbes.

The demand for antimicrobial products is increasing. More and more owners and engineers are requesting it for its effectiveness in inhibiting the growth of damaging bacteria, mold and fungi. AgION antimicrobial-coated steel ductwork is durable and should be incorporated into HVAC systems for hospitals, pharmaceutical facilities and food processing amenities, schools, daycare centers and nursing homes.

AK Coatings’ AgION Antimicrobial Steel. We are incorporating their steel into our complete line of Heating, Ventilation and Air Conditioning ductwork. SPOT `AgION is our name and available through our knowledgeable team. Please call today for more on our destructive microbe SPOT AgION duct work.


The AgION™ antimicrobial compound is a long-lasting, inorganic material that contains silver ions — a safe and natural antimicrobial agent. The compound has two key components working together to suppress the growth of microbes: Silver Ion (the active agent) and Zeolite (stores the silver ions and releases them).

When moisture is present the Zeolite gives a controlled release of silver ions into the environment. This release provides continuous antimicrobial protection for the product. As the humidity increases, and the environment becomes ideal for bacterial growth, more silver ions are released.

For most types of bacteria, the treated surface will be virtually free of microbial contamination within three to four hours, protecting the product from degradation for the life of the coating. The coating life is a function of the application and surface wear.

Coated products must still be cleaned to insure the surfaces will be free of destructive microbes. This serves as an added cleanliness to support regular cleaning routines between each cleaning. The coating life is a function of the application and surface wear, but could average between 10-30 years depending on the thickness of the coating and the wear it receives.

The coating containing the AgION™ antimicrobial compound shall withstand temperatures not to exceed 350F for an extended period of time.


AK Coatings offer antimicrobial-coated galvanized, carbon and stainless steel products up to 60 inches wide in gauges from .018 inch to .060 inches. Products are also available up to 48 inches wide in gauges from .060 inches to .075 inches. Heavier gauge coating capabilities are currently being developed.

SPOT AgION™ Antimocrobial Steel duct can be produced in rectangular, round, flat oval and thermal acoustical panels as supplied by Spiral Pipe of Texas, Inc. Duct system components shall be manufactured from gauges defined in SMACNA’s Duct Construction Standards – latest edition. Coating containing the antimicrobial compound shall have a hardness of 2H minimum when tested per ASTM D3363.


The AgION™ antimicrobial compound is blended into a paint system and applied to AK products by continuous coil coating. The interior surface is treated with the AgION™ antimicrobial coating uniformly and applied with a minimum thickness of 0.1 mils. An untreated clear coating is applied to the exterior surface of the duct. [If necessary, both surfaces of the ductwork can be treated with the coating containing the AgION™ antimicrobial compound].

Gaps in the coating wider than 1/4” shall be repaired in order to maintain product performance. Repair kits are available in spray or brush applications and can be purchased through Spiral Pipe of Texas to the installing contractor.


Rectangular Ductwork
Round Ductwork
Oval Ductwork
Thermal Acoustical Panels

Maximum Temperature: 350F

Smoke/Flame Spread: Virtually 0


Gauge: 26 gauge to 18 gauge

Width: Maximum 60"


Antimicrobial compound is registered with the EPA (Environmental Protection Agency) and FDA (Food and Drug Administration).

Antimicrobial coated product conforms to Standard 723 – not to exceed flame spread or smoke developed ratings of 25/50.

Antimicrobial coated product complies with ASTM B117, ASTM D247, and ASTM D870

Spiral Pipe of Texas

Our Products

SPOT is taking all precautions during the COVID-19 coronavirus pandemic. We do remain OPEN FOR BUSINESS and stand ready to serve you. We are limiting customer service interactions to PHONE and EMAIL ONLY however our offices are closed to in-person visits.