| 摘要 |
<p>To the housing part of a backflow-preventer for a sanitary device there is fastened an outer sleeve, made from elastomeric material, exhibiting a sleeve section which is distanced from the housing part. The outer sleeve embraces an inner sleeve which is fixedly supported to the housing and includes a supporting section, which is dimensioned such that the inner sleeve, when acted on by water flowing in the direction of flow, cannot fold inward. The sleeve section bears, under pretensioning, against the supporting section and is expanded by the pressure of the water so as to clear an opening between the sleeve section and the inner sleeve. If the water current is interrupted, the outer sleeve immediately bears again against the inner sleeve. The end sections of the inner and outer sleeves are configured like a sealing lip. The backflow-preventer prevents water from flowing back, even under the least underpressure on the feed side. Moreover, it is not sensitive to foreign bodies.</p> |
