Are generally a passive non-return valve to prevent back flow up the drainage pipe. Used on out falls as flood prevention. The term non-return valve covers a wide range of products manufactured from metals to plastic. The basic function is to allow flow out of a pipe line freely, should water begin to build up from the downstream flow the non-return valve is forced to close by the hydraulic pressure.
The basic non-return valve can often be seen on headwalls at the seaside, rivers or canals. The flap also acts as a none return device; preventing debris or rodents entering the drainage from the river bank. New inline non-return valve are often used to meet new flood defence building regulations. Once these valves are installed it is impossible to see if they need cleaning.
Many industries today rely on these simple devices to control back flow flooding with new inline pipe products developed to supply into the new build sector. When flooding occurs, the drain is isolated preventing flow getting back into the property. This simple device can be flawed as the passive nature of its design means it can easily “rag” or become blocked by leaves, twigs, toilet waste and many other items that may catch in the non-return valve preventing it from fully closing during flooding. If a non-return valve fails to fully seal flow will be slowed but it will still enter a building, failing to prevent contamination.
Toggleblok™ has been designed to work as a simple non-return valve but when triggered by a flood alarm the flap is driven shut with a cutting disc capable of cutting through many items that would block a normal passive flap valve. If larger debris prevented the valve from shutting the Toggleblok™ system will go into alarm giving the operator a clear signal that the flood control is not fully sealed and further action is required.
If spill containment and CIRIA736 compliance is currently a consideration for you please do not hesitate to call 0330 223 4372 or email us, we will be very happy to discuss our solutions with you.
