KIWA Approved Pipe Interrupter
Type DC – Pipe interrupter with permanent atmosphere vent.
Backflow Prevention Device means either a Type A or Type B air gap, a check valve, a double valve, a double check valve assembly, combination of check valve and vacuum breaker, a pipe interrupter, or some other water fitting or arrangement of water fittings designed to prevent the backflow or backsiphonage of water;
pipe Interrupter means a non-mechanical device without any moving, flexible or elastic parts which –
(a) in the event of any vacuum in a pipe in which it is installed will admit air into it to prevent the backflow of water;
and
(b) (i) is resistant to water corrosion and is immune from, or resistant to, dezincification; and
(ii) has an obstructed air inlet-aperture, or apertures which, when a vacuum occurs on the inlet side, produces a corresponding vacuum on the outlet side not exceeding 5mbar below atmosphere.