초록 ▼

A method for reducing the risk of freezing of surface-water pipe-line systems of the kind comprising a plurality of drains and other inlets, such as rain-water drains, manholes and inlets from terrace and roof guttering, etc. Means are provided which prevent or reduce air currents in at least one of

A method for reducing the risk of freezing of surface-water pipe-line systems of the kind comprising a plurality of drains and other inlets, such as rain-water drains, manholes and inlets from terrace and roof guttering, etc. Means are provided which prevent or reduce air currents in at least one of the drains and other inlets through which the flow of air would otherwise be excessive. The means is designed to permit water to flow therethrough without appreciable gathering of water therein.

대표청구항 ▼

Pipe-line system for surface-water including a plurality of drains and other inlets, such as rain-water drains, manholes and inlets from terrace and roof guttering, etc., characterized in that in order to reduce the risk of freezing of the system special means (5) are mounted in at least some of the

Pipe-line system for surface-water including a plurality of drains and other inlets, such as rain-water drains, manholes and inlets from terrace and roof guttering, etc., characterized in that in order to reduce the risk of freezing of the system special means (5) are mounted in at least some of the drains (1) or other inlets which are so located that the flow of air therethrough can be heavy, said means (5) being arranged to reduce such heavy flow of air in both directions through the respective drain but not to prevent some ventilation of the system and designed to permit a small flow of water to pass directly therethrough without appreciable gathering of water in said means and to be automatically opened when required to permit a greater flow of water to pass.