Plumb line positioning system for waste water pipe - uses sleeve with viewing window adjacent index point to avoid disturbing water

摘要

A plumb line is lowered through an inspection chamber into a pipe in which used water flows containing various substances. The line is positioned accurately without the need for emptying or disturbing the flow to allow ground level to be checked. The base of the inspection chamber has holes to allow lower access tubes to enter the pipe. Upper access holes allow a plumb line to be suspended from a tripod to pass through a sheath supported by a bridge in the lower holes. The plumb weight is lowered to an index point fixed to a support mounted in the pipe. Sealed windows in the sheathe adjacent to the index point allow the point to be visible to verify alignment of the weight.