The motor-fuel supply in the United States has never been more diverse. It really wasn’t all that long ago that service-station operators were able to offer their customers a simple either/or choice: regular leaded gasoline or diesel. That changed with the creation of different grades of unleaded gasoline, and more recently, the increased usage of ethanol- and biofuel-based gasoline and diesel.

While this expanding menu of alternative fuels has been beneficial for engine manufacturers, motorists and the environment, it has put increased pressure on service- station operators. They now must be keenly aware of the specific handling characteristics of a broader range of fuels. This means they must be certain that the hanging hardware and underground storage tank (UST) equipment and systems they deploy on the forecourt are compatible with the expanding list of fuel formulations and that, most importantly, they have been tested and approved by a reputable third-party certification organization.

Most fuel retailers know that ethanol and biodiesel are structurally different from unleaded gasoline and straight diesel. They’re probably also aware that ethanol is compatible with ductile iron and 304/316 stainless steel, but not aluminum, and with polymers like polytetrafluoroethylene (PTFE, or Teflon®) and polyoxymethylene (POM, or acetal), but not Buna-N, nylon and urethane. Similarly, they may be aware that biodiesel will react poorly with metals like lead, tin, copper, zinc, along with brass and bronze alloys, while playing well with aluminum, stainless steel, PTFE, Buna-N, high-density polyethylene (PE) and Viton®, but not natural rubbers.

What the retailers may not know is that there are different compatibility requirements within the specific product families, so that formulations like E10, E15 and E85, or B5, B20 and B100 can all react differently to the same fuel. This means that a retailer who assumes that all formulations of biodiesel possess the same handling characteristics might experience difficulties if he chooses to pump B20, but outfits his forecourt with equipment that has been approved only for use with up to B5. The most common problem in a scenario like this is the failure of seals, gaskets and hoses that can lead to dispenser and UST leaks that may require expensive cleanup and remediation operations and, in a worst-case scenario, a potentially dangerous fueling atmosphere for the driver, site personnel, surrounding community and the environment.

That’s where third-party testing organizations can be the retailer’s best friend. In the United States,
Underwriters’ Laboratories (UL) is the preeminent third- party equipment testing and certification organization, with the “UL Approved” stamp accepted industrywide as proof that the equipment will perform as expected if used in the proper manner.

Getting the Hang of It
The task of choosing the best hanging hardware for the fueling site’s fuel menu is also assisted by the manufacturers of breakaways, hoses, swivels and fuel-dispensing nozzles, who take great pains to ensure that their products can pass muster with UL. To further ease the burden on retailers, some manufacturers are now packaging their formulation-specific and UL- approved hanging hardware
in kits that are shipped to the fueling site fully assembled after they have been factory tested for leaks and continuity, which means that they will perform as expected despite changing atmospheric conditions.

Here are the components in a Hanging Hardware Kit that
has been dedicated for use at dispensers that pump specific formulations of unleaded gasoline or diesel with different alternative-fuel levels:

  • Nozzles: Many nozzles are now UL-listed for use with all three ethanol-blended fuels (E10, E15 and E85). They are equipped with a “No Pressure – No Flow” device that prevents fueling until the pumping system is pressurized, while closing automatically when the pressure is removed. The nozzle’s body and spout are constructed of aluminum, but plated with nickel to protect them from degradation that can occur with higher ethanol concentrations. Seals are Viton with graphite/PTFE packing.
  •  Swivels: Tested and approved for use with E10, E25 and E85. The body is aluminum with nickel plating with outlet and inlet adapters constructed of zinc with nickel plating. Seals and bearings are Buna-N, Viton and nylon.
  • Breakaways: UL-listed for use with all ethanol blends, as well as B5 and B20 biodiesel blends. Constructed of die- cast zinc and Zamak, with stainless-steel main springs and protective sleeves of Zytel and impact-resistant nylon. Seals are made of Viton and fluorosilicone.
  • Whip and curb hoses: The whip hose is the short piece of straightening hose that is used to connect the dispenser to the breakaway. Curb hoses are typically 2.6 meters (8.5 feet) long and connect the breakaway to the fuel nozzle. They are third-party approved for use with E15 and E85 fuel blends, along with B20, with a steel reinforced hardwall that is flexible to -40 degrees Fahrenheit (-40 degrees Celsius) and chrome-crimped ends.

Going to Ground
While retailers can quickly identify if a piece of hanging hardware may be leaking or on the road to failure, it’s not quite as easy with the fueling site’s underground storage tank (UST) system. To assist in this area, UL offers its UL-2447 “Containment Sumps, Fittings and Accessories for Fuels” standard. UL-2447 specifies a test program for UST sumps that are constructed of new-age fiber-reinforced polymer (FRP) fiberglass via a Vacuum-Assisted Resin Transfer Molding (RTM) manufacturing process, which has been shown to outperform other methods of making an FRP sump. The UL standard also applies to traditional polyethylene (PE) materials of construction.

To earn UL approval, the manufacturers of sumps must create products that can satisfy a series of performance tests:

  • Leak prevention: Must be able to retain at least 70 percent of Type A (solid combustible materials) and Type B (flammable liquids) fuels, as opposed to the old standard requiring retention of 50 percent of Type A and 30 percent of Type B fuels.
  • Fluid compatibility: Sump samples are immersed in Type A and B external fluids for one to nine months, and in Type A and B internal fluids for one month. After these testing periods, the 24 hours, no leakage can be observed.
  • Air-oven aging: Sump samples are placed in an oven at a temperature of 158 degrees Fahrenheit (70 degrees Celsius) for one to six months. At an equipment-procurement process that results in safer, more efficient, reliable and compliant operations for retailers, along with site personnel, drivers, surrounding communities and the overall environment. sumps must test within a completion the sump must range of flexural strength (50 percent for Type A and 30 percent for Type B) as a like-new sump.
  • Cold impact: Sump samples are frozen to a temperature of -20 degrees Fahrenheit (-29 degrees Celsius) for 16 hours before having a 1.18-pound (0.53 kilogram) steel ball dropped on it from a height of 6 feet (1.8 meters) with no cracking allowed.
  • Hydrostatic load: Sumps with penetration fittings are filled to capacity with water; after have flexural strength of at least 80 percent of a like-new sump.

    As the menu of motor-fuel options has grown — along with the simultaneous demands placed on retailers to ensure the proper, fuel-compatible operation of their hanging hardware and UST systems — manufacturers of this critical equipment have taken great pains to develop products that can achieve the coveted UL Seal of Approval. The result is an equipment-procurement process that results in safer, more efficient, reliable and compliant operations for retailers, along with site personnel, drivers, surrounding communities and the overall environment.

    Ed Kammerer is the director of global product management for OPW Retail Fueling, based in Cincinnati, Ohio. He can be reached at OPW is defining what’s next in fueling solutions and innovations worldwide. OPW delivers product excellence and the most comprehensive line of fueling equipment and services to retail and commercial fueling operations around the globe. For more information on OPW, please go to