VACUVENT VA Series, Owner'S Manual

Page: 17 / 18

Independent Valve Marketing (Pty) Ltd
Engineering Page 17 of 18
VSS0203WD00
PIPELINE AT OPERATING PRESSURE
Venting of large quantities of air via the anti-shock
The valve will respond to large volumes of air when at operating pressure in the same manner as it
does during filling – this function is fully automatic through the smart anti-shock orifice as in the
previous figure.
Air Release from a Pipeline under Pressure (Small Orifice)
Figure 7- Air Valve Pressurised Air Release
In the above figure one can see the air accumulating in the valve with the pipeline under pressure,
generally only when small amounts of air enters the valve through the pressurized system – again
this operation is automatic. The air travels through the lower portion of the upper float and exists
through the small orifice, item 2, which in turn flows out of the anti- shock orifice, item 3.
PIPELINE DRAINING
Air Intake of a Draining Pipeline
Referring to the following figure:
Any negative pressure present within the pipeline causes the atmospheric air to force its way in
through the large orifice by pushing the upper float, item 1, downward on to the lower float, item 2,
at the bottom of the valve.