PRE NOTES:
A) VENTING OF A FILLING PIPELINE:
The operation of a conventional sewage air release valve is such that fast approaching sewage/effluent is almost instantaneously halted by the valve's closure. Consequently surge pressures of potentially damaging proportions can be generated in a pipeline system, even at normal filling rates.
In addition to venting through the Large Orifice when sewage/effluent approach velocities are sub critical, the Vent -O- Mat series RGX sewage air release valves feature an automatic "Anti - Surge" Orifice device that serves to decelerate sewage/effluent approaching at excessive speed, thereby limiting pressure rise in the pipeline.
B) SURGE ALLEVIATION - PIPELINE PRESSURIZED:
In instances where a pipeline experiences liquid column separation due to pump stoppage, high surge pressures can be generated when the separated column rejoins.
The Vent -O- Mat series RGX takes in air through the unobstructed large orifice when column separation occurs, but controls the discharge of air/gas through the "Anti-Surge" Orifice as the separated column commences to rejoin. The rejoining impact velocity is thereby sufficiently reduced to prevent an unacceptably high surge pressure in the system. In the same way the series RGX valve prevents high surge pressures resulting from liquid oscillation in a pipeline.
