Drones do reduce risk as human entry is not necessary – in fact, many pipes are too small for a person to enter but big enough for a drone. It is vital that a full risk assessment is completed prior to any work, and this must include a retrieval strategy for the drone should it become stuck. Other factors to consider before a drone can be deployed inside pipework include:
Most pipework is not laid in long straight lines and so it is important to understand as much as possible before any drone flight, if there are any likely obstacles in the way of the drone that it could get caught on. This could include materials that have become dislodged from the pipe itself, fallen into the pipe from above, or travelled through the pipe.
Physical dimensions and layouts of pipework
The maximum distance a drone can fly with a range extender in use, is approximately 200m – in a straight line. This reduces to around 160m without a range extender and reduces further when the pipework is not straight. Often pipes have uplifts or bends and these reduce distance a drone can travel.
Presence of liquid
Drones do not like liquid and cannot fly very close to liquid. What’s more, if the pipe is very narrow, the down draft created by the drone can blow the liquid up the side of the pipe and cause the drone to lose power and malfunction.
Flammable substances and dust
It is important to understand what material has travelled through the pipe in the past that could cause issues for the drone’s flight. If any flammable substances have been in contact with the pipe in the past, the pipe must have been cleaned thoroughly and relevant testing carried out before any drone is flown in the space.
The drone is not ATEX rated so this does rule out operating it in some environments. The drone has a battery and propellors that create static energy. However, a risk assessment and method statement with appropriate control measures in place, may allow the drone to operate in an ATEX rated area.