All kinds of liquids are constantly being moved through the supply chain, including everything from milk to fuel, and from inks to industrial-grade liquid plastics.
The key to moving the liquids you need from the supplier to the warehouse or factory safely and efficiently depends on choosing the proper container. Size, composition and capacity are just three of the factors that need to be considered before choosing the right one.
How Liquids Are Transported
Some liquids, such as crude oil, are often moved without any container at all. Instead, they are pumped via underground or overland pipelines from the oil fields or offshore drilling stations to refineries where they can be transformed into motor fuels and other products.
Others, such as milk and liquid eggs, are often put into end-user containers such as plastic gallon jugs or bladder bags directly at the point of manufacture, such as the dairy farm or poultry factory.
But some liquids require bulk liquid containers that are constructed of plastic tanks that are fitted inside light-duty metal support frames.
Disposable vs. Multi-Use
In some instances, these bulk containers are disposable after the first use. But Mark Spurrier, vice president of sales and Marketing for Snyder Industries — a plastic tank manufacturer based in Bensenville, Illinois — said more and more users are looking for containers that can be used over and over again.
“Customer want more durable liquid handling containers that can be returned and reused in a closed loop, over and over, for a long period of time,” Spurrier told Modern Materials Handling. “This allows them to maximize their investment, be a steward of the environment, and eliminate disposal issues.”
Choosing a Portable Fluid Tank
Because all sorts of liquids are placed into these portable tanks, a number of different factors need to be considered before selecting the right one for your specific applications. These include the chemical composition of the liquid, its acidity or flammability, corrosion resistance, weight, and viscosity.
Dispensing requirements are also critically important. Some liquids — such as water, for example — will flow freely once a hole at the bottom of the tank is opened via a valve. But other liquids require a little help to drain properly.
For example, containers that are going to hold grease or printer’s ink are often equipped with a follower plate. This device is a metal or plastic plate whose edges are flush with the sidewalls of the container. Pressure is placed on the plate so that it scrapes the interior walls of the tank as the fluid is pumped out.
Secondary Appliances
In other applications, other devices known as secondary appliances need to be added to the tank to make it work efficiently, according to Spurrier.
“For liquids that need to maintain a higher purity standard, the container can be equipped with special draw tubes and return connections for filtration purposes,” he said.
Another consideration is the weight of the liquid. Some fluids, such as sulfuric acid, can weigh nearly twice as much as the same volume of water.
“Knowing the limits of the container impacts its warranty, projected useful life, stack rating, and the compatibility of its construction with a particular liquid,” Spurrier said.