Moisture seal-out solutions in fuel handling

Water contamination is a key safety concern in liquid-fuelled machinery. Such contamination affects surface and underground storage facilities as well as mobile tankers and dispensing equipment supplying aviation, diesel and petrol fuels. These fuels all contain some water in suspension, yet if this water exceeds certain levels, problems can occur. Such problems include: clogging, corrosion, engine damage and, in extreme cases, failure and explosions. In particular, diesel fuel is less refined than petrol and holds a greater amount of water, while even small amounts of water in avgas and jet fuel can be dangerous to life. CSGtech works to provide contamination protection in this space. As the company’s seals and gasket technology specialist, Vinh Lam, explained: “Because of the dangers water presents to all fossil fuels, a whole host of industries are focused on compliance with safety, handling, storage, dispensing and environmental standards.”

A recent sealing challenge that CSGtech addressed involved underground fuel storage protected by a hatch that incorporated a seal made from extruded product and included a circular seal with a diameter of 500 mm. The aim of the project was to optimise protection against water penetration and achieve an extended lifespan, while also withstanding the high and variable weights of passing traffic and varied weather conditions. The company worked with their customer’s engineers to redesign the sealing solution. This involved utilising a different manufacturing process in which a seal was moulded without jointing, using a high-density material that was durable but flexible. It was softer and more compressible, while maintaining durability and regular shape. Although the initial cost of the individual part was higher, this investment was offset by increased whole-of-life performance. Costs were also reduced in the long run in the areas of quality control and rejects, replacement and ongoing service.

“As a result, there was no need to redesign the hatch involved, which continued to perform even better for longer with the new seal, without the need for any expensive redesign or replacement,” Lam said. “This was a key point of our solution, which involved redesigning a component so there was minimal impact to a legacy design, which could continue to serve the customer well.” In terms of the issue at hand, Lam elaborated: “As a result of the manufacturing process, there may be some small but persistent irregularity in the cross-sectional diameter of the tube. This can result in different size ends, which, in the joining process, have to be trimmed back to correct any irregularity. Not only does such a joint create a potential weak spot, but also the problem can vary from batch to batch, joint to joint.”

Vinh Lam (left) and Ben Vocalan of CSGtech examine and develop specialist seal profiles for particular applications.

The sealing solution employed was straightforward from introduction into production after the problem had been isolated and tested using a selection of componentry that adhered to national and international compliance and materials verification standards that are required for fuel handling operations. “The strengths we brought to the partnership with the manufacturer in this instance included sourcing, understanding and testing compliant materials to deliver an assured result engineered to national and global standards,” Lam said.

“Even the excellent operations, engineering staff and manufacturing and engineering consultants we deal with appreciate that they cannot be totally knowledgeable in all specialist areas. Rather than use their resources to discover a solution that might already exist — or, worse, engineer a solution that doesn’t work as they wish after investing their time — they streamline the process, by getting the material selection and production processes correct from the beginning. This is the logical and time-efficient way of approaching an issue. It’s the correct planning process to arrive at earliest results and achieving the earliest production opportunity,” Lam added.

Top image credit: ©stock.adobe.com/au/Tyler Olson