requiring certified installation and annual checks. They are used for category 4 systems, such as fire sprinklers where the system has an antifreeze additive.

Air gaps

Back siphonage may be prevented by use of a vertical air gap. This may be a small gap, such as provided by a tundish (a combined overflow spout and catch funnel) or a large gap, such as a basin tap being above the maximum level of the water

1.Previous
3.Next