Definition - What does Efflux mean?
Efflux is defined as the rate at which a liquid flows out of a system. Depending upon the type of liquid, the efflux time varies. A liquid with higher viscosity or one with solid particles will have a higher efflux time. It also depends upon the slope at which the pipeline has been laid to enable gravity to act as, in the context of trenchless technology, efflux is the time taken for draining liquid out of the sewer pipeline under the effect of gravity.
Trenchlesspedia explains Efflux
The efflux time of a fluid from a pipe depends on many conditions. A fluid with only water will have a lesser efflux time than that which contains a more viscous fluid. While water pipes may not pose a problem, often sewer pipelines get clogged. This is because sewer pipes carry semi solid waste water that decreases the normal flow rate of a liquid. Other factors that contribute to greater time of efflux is friction, exit pipes and other pipe fittings.