Liquid drain system

Claim 1

A drain system for draining, from a settling chamber of a trapping device, foreign liquid which has separated from a supply liquid flowing through the device, the foreign liquid having a specific gravity greater than that of the supply liquid, the drain system comprising a float in the form of an annulus in the lower part of the settling chamber and having a specific gravity higher than that of the supply liquid and lower than that of the foreign liquid for floating on foreign liquid in the chamber, a column for guiding the float along a predetermined path in the chamber as the float floats on the foreign liquids, said annulus encircling said column and being rotatable about said column by movement of liquid in said chamber, an indicator located in and movable with the annulus of the float, a sensor mechanically isolated from the indicator, said sensor being arranged in said column for actuation by the indicator when the indicator moves to a predetermined region of the predetermined path, an electrical signal circuit means responsively connected to said sensor for causing an actuating signal in response to detection of a predetermined quantity of foreign liquid in the settling chamber, and means responsible to such an actuating signal for effecting drainage of foreign liquids from the chamber.