Positive displacement meter assembly for open drains - uses counterweight arrangement to ensure constant back pressure on meter, regardless of flow rate and depth in drain

摘要

The waste liq. (3) flows from a drainpipe (4) in the wall (2) of the trough (1), into a pressure release tank (5) which is connected by a vent (6) to the outside air. The liq. then flows through a flexible pipe (7) to the meter assembly (8), which is supported at a constant level w.r.t. the level (9) in the trough by a chain (13) and weight (12) system. The advantage of this sytem is that the meter operates at a constant back pressure regardless of the flow rate or the level in the trough.