The Pollution Solution

Double acting air valves are generally assumed to be simple mechanical devices
but are in reality, due to the unpredictable nature of air, complex in operation.
Inherent in all conventional air valves, is the creation of either surge or water
hammer on closure of the large orifice. Manufacturers have over the years
developed various auxiliaries to protect air valves and pipelines from the
damaging effect of surge and water hammer, and other phenomena as a result of
air release. This document describes the phenomena affecting efficient air valve
operation by analysing various air valve designs, and introduces CATT
(Controlled Air Transfer Technology) a revolutionary, well tested, concept in air
valve design and surge/water hammer alleviation.