Rectilinear, reusable IBC tanks fill liquid transport niche for GOM contractors
In a regulatory climate where used steel barrels and drumsare becoming less welcome at both refuse and recycling facilities, rectilinear reusable tanks are making greater inroads into the gas, oil and mining markets as liquid transport and intermediate bulk containers (IBC). The reusable stainless steel tanks fill their footprint more efficiently than cylindrical containers and are designed for stacking while being transported.
Hoover Materials Handling Group Inc., headquartered in Houston, Texas, has been manufacturing stainless steel tanks for more than 50 years. “These were initially produced for the chemical industry,” says Arash Hassanian, director of international business with Hoover. “The basic designs were very similar but we’ve made a lot of refinements since then. At this point, the gas and oil market is our biggest customer, with a more significant use of the containers in the Australian mining industry.”
The company’s bestseller to the gas and oil sector is the Liquitote Stainless Steel series, made of 10-gauge stainless steel using 304 and 316 alloys with a single-seam welded body. While some legacy containers are still made of carbon steel, the rising price of the material has virtually eliminated any new construction of these units. The series ranges from 350 gallons (42 inches long by 48 inches wide by 51 inches high), to 550 gallons (the same footprint but 75 inches high) to 793 gallons (54 inches long by 54 inches wide by 77 inches high).
“The larger units were developed for one customer and we gradually expanded production of that model,” says Hassanian. “This model is especially popular for use in offshore rigs involving deep sea drilling. They’re interested in anything that can get a larger volume of chemicals to the platform in one trip.”
IBCs can be emptied from the side or center, but the slightly sloped design of the bottom of the containers can significantly reduce product waste when the lower option is used. A drum typically retains about 3 percent of the material inside, says Hassanian, while an IBC retains about 0.5 percent.
CARRY THE LOAD
“The IBCs are usually used in the gas and oil sector for fuel, grease, solvents, corrosion inhibitors, scale inhibitors, lubricants, antifreeze, coolants and cleaning fluids,” he says. “The decision to use IBCs over drums is usually made by the end user, who specifies the type of container. In many cases, however, the end user is now the contractor servicing a gas or oil field with an array of chemicals.”
IBCs can safely carry a wide variety of chemicals related to the GOM sector, although service companies should specify their intended use to the supplier to obtain chemical compatibility information on both the tank and its gaskets before placing an order.
“Customers are becoming increasingly sophisticated in understanding the capabilities of IBCs to contain specific chemicals,” says Hassanian. “We’re here to help them if they have an unusual situation, for example, whether an IBC can safely hold a particular chemical at extremely low temperatures.”
All chemicals carried in IBCs must be delivered at atmospheric pressure – they’re not designed to carry pressurized liquids.
Fitted with stainless steel legs on bottom and lifting lugs on top, the IBCs provide firm seating to nestle together as they’re stacked. Pallet stacking is unnecessary because channels underneath each container allow easy forklift access from either all four directions, or two, to avoid drain accessories on some models. IBCs can also be top-lifted, providing all four lifting lugs on the top corners are used.
The steel IBCs are rated to deliver any material up to Packaging Group II, and Group III, which covers a wide range of chemicals, for over-road delivery, and are UN/DOT certified. The containers can also be delivered intermodally, arriving or leaving by truck, van, rail or sea.
“Liquitotes are usually delivered on a flatbed or in intermodal containers, with no wasted space between the units like you would have with circular drums,” says Hassanian. “That’s important both in transportation and at the warehouse. One 550-gallon IBC carries the same amount of liquid as 10 55-gallon drums, but uses considerably less floor space and you can stack them higher. If you use drums, every four drums must be wrapped and placed on a pallet, so 10 drums would require three pallets, and 10 labels plus wrapping.”
LONGER SERVICE LIFE
Unlike steel drums, steel IBCs are reusable if cleaned and have an average service life of about 20 years, with lifespan depending on the nature of the chemicals used.
Hoover also produces rotation-molded plastic tanks, which are housed in a protective cage, and are used in the GOM sector to haul anything from acids to bulk water to remote locations. They’re also recyclable with a service life of five to 10 years. The company’s Tuff Tank is its most rugged and long-lasting polyethylene IBC, designed for transportation or storage of hazardous liquids. The tank is designed for the harsh environments of offshore rigs, including such factors as salt spray, chemical exposure, and falling objects.
Hassanian notes that many landfills no longer accept either drums or barrels and recycling is problematic because of concerns about chemical contamination. A series of federal, state and local environmental regulations requires the drums to be carefully cleaned, often through the application of extreme heat, before being crushed and recycled, a process billed to the end user.
If the IBCs are used to deliver a different chemical following delivery, the smooth stainless steel interior must be washed first. Hassanian says this can be achieved in most cases using a high-pressure water spray, or by sending the units to specialty IBC cleaning facilities. “Every time a unit is washed, it should be air-tested, because some of the parts must be disassembled and reassembled for proper cleaning,” he notes.
Because of their extended service life, IBC tanks are either sold outright – or leased by some manufacturers using a simple contract based on a daily fee. These containers can be cleaned and returned at any time. Replacement parts sold by distributors include drum covers, gaskets, clamp rings, fusible vents, ball valves, connection fittings, nuts, bolts, pressure vacuum relief vents and bung plugs.
All steel IBCs must be leak-tested every 30 months according to federal DOT regulations, and all tanks with UN markings must be thickness-tested every 60 months; a service that can be provided by the supplier.
EMPTY TO FULL
Liquitotes can be left outside for storage purposes in a variety of climates, but like drums and barrels, don’t protect the contents from either heat or cold. IBCs can be fitted with heating jackets and coils or bellybands to warm the contents in the same fashion as drum warmers.
IBC tank covers are clamped into place using lock nuts. Before removing the cover, the tank’s internal pressure must be equalized by opening its bung plug. The lid can then be pulled loose from the gasket seal in which it’s seated.
Likewise, before filling a tank, all drains must be sealed and the bung plug opened to release any internal pressure inside the tank. The tank is filled using an aperture fitted with a vent that allows displaced air to leave the tank as liquid enters it. The lid is then sealed, clamped and locked, and the bung plug is closed.
UPGRADE AND ADAPT
The design of the square tank also allows for a series of optional upgrades, including full port ball valve, SS camlock, upgraded gasket materials to meet various compatibility requirements, level gauges, vacuum-vent equipment, pumps, mixers, additional outlets, top openings and dip tubes.
The containers can be uniquely tagged, and tracked anywhere in the world either by the supplier, or by the contractor using asset management software. Hoover employs its own Liquitrac system employing GPS or cellular devices. Using this system, IBC tank locations, fill levels, test dates, container condition, types of cargo and delivery information can also be monitored.
“If clients request the service, Hoover will inform the client when a test is due and come to the tanks to test them,” says Hassanian. “In some remote locations, the only other testing option would be to ship the containers out to the testing facility.”
Steel IBCs continue to be adapted to customer needs. They can now be specified as double-walled to transport flammable products and hazardous chemicals where transportation and environmental regulations demand it.
Companies including Hoover are helping service companies to assemble fracking packages that link a number of tanks using a manifold assembly and flexible tubing.
“We’ve provided 23 special IBCs assembled into a single fracking package system to supply water and chemical additives for shale operations,” says Hassanian. “IBCs are deceptively simple, but they can be adapted to suit the more complex needs of the industry.”