Hennig Enclosure Systems Division

Let us be your exclusive source for all your custom stand-by power packaging needs. Hennig Enclosure System’s engineering & manufacturing expertise, customer committment, quality, capacity and service are just some of the reasons to make Hennig your sole supplier of back up power generator enclosures.

Along with the enclosure, HES also offers a range of five types of UL 142 and UL 2085 certified fuel tanks, including secondary containment tanks, open and closed-top dikes, freestanding day tanks and sub-base day tanks. All tanks come standard with a minimum 110% containment area and a range of standard features, including rupture basin alarms, electrical stub-up areas, fuel level gauges and senders, vents, manual locking fill caps and 0.5 in. NPT drain plugs.


  • IBC Certification
  • Industrialized Building Code Certification
  • UL2200 Certification

Engineering Expertise

Hennig’s engineering staff has extensive experience in the design and manufacturing of enclosures. Our engineers use the latest CAD 3D modeling programs to develop your enclosures, allowing us to build a virtual model of your enclosure before we ever manufacture it. With this capability, our customers are able to see the finished product before we even cut the steel. Hennig has manufactured many enclosures for machine tools, requiring tight tolerances for complex operations.

From 3D CAD Model

Our skilled Engineers start with CAD to develop concepts to optimize designs and confirm the project is built within specifications with detailed drawings.

To Finished Enclosure & Fuel Tank

Once the drawings are approved, we move into production. This transition between the engineers and factory floor specialists is seamless.

Post Production

    When a Hennig product leaves the facility, our job is not over. We make sure all enclosures and installations perform to or highest standards in the field.
    Hennig ensure products perform in the field and follow up with on-site visits.
    Hennig backs all products with a guarantee.

Quality Engineered Design

We are dedicated to providing a top quality Enclosure System the first time. Hennig Enclosure Systems are designed to endure catastrophes. We start by designing them to withstand high snow loads and 120 mph winds as standard features. We then use only the highest quality material to construct your enclosure system. Our enclosures are laser cut to ensure that every piece is both accurate and consistent. We use CNC press brakes to form the product before paint. Once all the parts are completed, each part is finished with a top quality powder coat for a showroom look and resistance to the elements. After painting, the enclosure is then assembled with close attention to detail by our highly trained crew.


You can rely on our ability to build the enclosure to suit your needs. In addition to our expertise and experience in enclosure manufacturing, we also have the capacity and the equipment to get the job done:

  • Powder Coat Systems (x3)
  • Wet Paint Booth for Large Tanks (x1)
  • Custom Built Enclosure Panel Welding Stations
  • Certified Welders
  • Steel & Aluminum Welding
  • Press Brakes (x4)
  • Folding Machines (x5)
  • Material Removal Equipment
    • Bystronic Fiber Lasers (x4)
    • Trumpf Lasers (x4)
    • WaterJet Machines (x2)
    • Various Metal Removing Machines (mills, lathes, etc)
  • Lasers
    • 5000 Watt Trumpf Laser
      • 80" x 160" sheets
      • Material Handling System
    • 6000 Watt Bystronic Fiber Optic Laser
      • 80" x 160" Sheets
  • 285 Tons of total crane capacity
  • Our largest systems are capable of lifting 60 tons
  • Testing Pad
  • Observational Control Room
  • Expanded Outdoor storage capacity

Case Studies

Michigan Milk Producers Association

W.W. Williams required an increased level of sound and environmental protection on three generating stations in accordance with their customer's architectural firm.

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W.W. Williams MTU GenSets

In association with W.W.Williams, as part of a government project, Hennig helped supply the enclosure systems to supply 9.75 megawatts of backup power. 

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Broken Arrow Water Treatment Plant

Hennig Enclosure Systems provided enclosures and fuel tanks for three Cummins 2MW generators at the Broken Arrow Water Treatment Plant in Oklahoma.

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