McEwan’s solution runs to a fraction of this cost and can be tailored for the specific conditions of the leak. Typically, the platelets vary in size from 0.3 to 50 millimeters, with shapes ranging from discs to cubes. Similarly, hardness has to be tailored to each situation: use too soft a material, and the platelets will deform under the pressure and be squished through the hole; use too hard a material, and they will fail to stem the flow through the leak. What is crucial is that the platelets are neutrally buoyant so that the fluid can carry them, says Evans.
The precise amount of platelets will also vary, with only a proportion of them actually forming a “scab” on the leak. Also, the buoyancy can be tailored to increase the chances of the platelets reaching the hole more efficiently. For example, if it is known that the leak is on the underside of the pipe, then using a slightly denser material that stays in the lower section of the pipe would be more beneficial.
Brinker has also been experimenting with ways to use the platelets not just to plug leaks but also to help locate them. “When you have pipes hundreds of kilometers long, just knowing they are leaking is a challenge in the first place,” says Burke. So far Brinker has tried using RFID tags with the platelets and even coating them with a harmless radioisotope.
The company is now seeking approval to start using its technology for water pipes. In England and Wales alone, 3,600 million liters of water is lost every day through leaks in the infrastructure, costing water companies billions of dollars in repairs and causing drivers untold disruption in the form of dug-up roads.