Cleaning system for vertical shaft with sump for drainage system has compressed air supplied to horizontal bubble pipe with non-return valve at end

摘要

The horizontal bubble pipe (3a,b) forms part of a cleaning system (2) for a vertical shaft (1) forming part of a drainage system. It is installed in the sump (1c) under a connection (1a) for a water inlet pipe. The connection for the outlet pipe (1b) is on the opposite side of the shaft. Compressed air (2a) is supplied to a vertical pipe leading to the bubble pipe which has a non-return valve at its end. This consists of a short vertical pipe (4) containing two balls which may float and hinder ingress of water into pipe when air is turned off.