W-51000 WASP Primary Fuel Filter
“The main design benefit of the self-clean filter range is that it can be serviced without being dissembled”.
The flow of fluid through the unit is not interrupted and consequently neither is the operation of the system/engine it is filtering for.
This automatic system can then be controlled by a timer; or for fully automatic operation by a pressure switch mounted on the output side filter. This would then trigger cleaning due to excessive pressure loss caused by a dirty filter.