UL 142 Generator Base Tank provides structural support for your backup or emergency power generator. The low profile design serves as the structural support for generator mounting, while providing storage for a wide range of fuels and chemicals, including conventional diesel and biodiesel.

The basic features of tanks covered by the UL 142 Listing include all containment spaces and their respective openings (manways, emergency vents, normal vents, fill/withdraw, gauging, monitoring and other functional openings) with connections (threaded- or flanged-type fittings) and integral tank accessories such as ladders, stairs, lifting lugs and heating coils or hot wells. All primary-tank compartment(s) are provided with openings to accommodate filling, withdrawing and inventory control; and all secondary-tank interstitial spaces are provided with openings for leak-detection monitoring.


  • OEM SUB Assemblies (Bases)
  • UL 142 Double Wall Containment Tanks
  • UL 142 Diesel Fuel Containment Cells
  • Long Run OEM Components


50 gal – 12,000 gal

UL 142 Construction Requirements

• Construction requirements – These include specification for the tank materials, joints, connections, fittings, manholes (if provided), fill, drain and gauge openings, and painting. They also include specific construction requirements for the primary and secondary containment means, supports, etc.
• Performance tests – These requirements include tank leakage, hydrostatic strength, top loading, buoyancy, hydrostatic load, tank support load, and lift lug tests that are designed to verify that the tank design does not exhibit signs of leakage and/or structural damage as a result of these tests.
• Markings and production line test – UL 142 requires tanks to include specific markings. In addition, 100% of production of each Listed primary and secondary containment tank must be tested for leakage by the manufacturer.