Big Changes are underway for the piston tank, a niche product used to transport and store highly viscous bulk cargoes. Changes include a new company name and plans for a new assembly facility.
As of January 1, 2008, the name was changed to Piston Tank Corporation, a subsidiary of Schilli Corporation in St Louis, Missouri. Piston tank assembly operations will continue in South Roxanna, Illinois, where the piston trailers have been put together since the 1980s.
“Our goal is to raise the profile of the piston tank,” says Robert B Schilli, president of Schilli Corp. “We have an opportunity to grow this business, and we're going to work very hard at achieving that objective. We will lease the piston tanks through Piston Tank Corporation, rather than through our Transportation Leasing Corporation subsidiary.
“Schilli Corp began acquiring the piston tank operations in 2000, and we completed the process in early 2007. We believe the product has a very well defined niche with good growth potential, both domestically and internationally.”
Piston tanks have been in operation since the mid 1970s, and the design was patented in 1974. The designer was George Berry, who also was one of the principals at CBW Transport Services Inc in Wood River, Illinois.
The piston tanks were developed to transport and store a wide range of viscous cargoes. Products that have been handled in the tanks include grease, paint, ink, caulking, peanut butter, and chocolate.
As designed by Berry, the trailers are essentially large grease guns on wheels. The tanks use the combination of an air-driven piston and a pump to unload virtually all of the cargo. Unloading takes approximately two hours, and heels are minimal (generally no more than five to 10 gallons).
In comparison, unloading can take four to 48 hours when viscous products are handled in traditional tank and hopper trailers. Heels can range from 500 to 1,000 gallons. That can mean expensive cleanouts and lost product for the shipper and consignee.
The first piston trailers were developed to transport bulk grease and consisted of three fiberglass cylinders mounted on what is essentially a platform trailer frame. Each of the three tubes holds 2,000 gallons of product. Some of these trailers are still in service.
However, the newest piston tanks in the fleet were constructed of stainless steel to DOT407 code. They have a full opening, flanged front head. Typical capacity is 6,000 gallons, which enables a 46,000-lb payload for most of the cargoes handled in piston tanks.
The heart of the system is the patented piston assembly. The pneumatically driven piston has airtight seals and a floating design. Following George Berry's death, the seals — essentially large inflatable O-rings — were developed by Burr Watson, who then was a partner at CBW Transport with Tom Berry, George's son.
The seals can be made of different materials to meet the requirements of the various cargoes. The O-rings fit so snugly that liquids, as well as viscous commodities, can be transported in the trailers. Spring-loaded pins keep the piston aligned in the tank.
“This is a very versatile system that can handle virtually any viscous product in a wide range of applications,” says Anthony DeJohn, vice-president of Piston Tank Corporation.
While most of the demand for piston tanks is in North America, an international market also exists. The piston system has been installed in swap tanks in Europe and in ISO tank containers that serve customers
in Asia. Even storage tanks have been fitted with the piston system.
One of the biggest changes for the piston tank came in the 1990s, when Berry and Watson parted ways. The Berry family owned a majority of the CBW Transport operation, and that included most of the physical assets and the patents covering the piston tank system.
Watson received a five-year agreement that allowed him to use one of the original piston tank patents. It also gave him the right to market the piston tank for foodgrade and hazardous waste applications. At the same time, Tom Berry received a patent for a much-improved foam seal, which eliminated unexpected failures that often occurred with the inflatable seal.
Four years later, Tom Berry contacted Schilli Corporation to see if there was an interest in leasing the piston tanks that were in the CBW Transport operation. In 2000, Schilli Corporation purchased all of the assets of CBW Transport, including the piston tank patents.
Then in early 2007, the Watsons sold all of their piston tank assets — including patents — to Schilli Corporation. All of these assets have been combined in Schilli Corporation's newly launched subsidiary — Piston Tank Corporation.
In all, Piston Tank Corporation controls a fleet of approximately 70 piston tank trailers in North America. Another 16 piston tanks are serving customers in Europe and Asia.
Piston Tank Corporation leases the tanks to its customers. The company also can provide transportation for the piston tanks through Schilli Corporation's tank truck carrier subsidiary — Truck Transport Inc.
“We believe leasing gives us the best means of serving our customers, most of whom are shippers,” Schilli says. “We can help them with all facets of managing the piston tank trailers. This approach also gives us the best opportunity to grow the piston tank business.”