| 摘要 |
THE PIPEWORK ELEMENT IS PROVIDED WITH AN EXTERNAL COATING COMPRISING:- A FIRST LAYER OF ZINC; ON THIS FIRST LAYER,- A SECOND, POROUS, LAYER OF ZINC/ALUMINIUM ALLOY CONTAINING FROM 5 TO 55% OF ALUMINIUM; AND ON THIS SECOND LAYER,- A THIRD, POROUS, LAYER CALLED THE PORE-BLOCKING LAYER, COMPRISING AN ORGANIC BINDER,ESPECIALLY A WATER-BASED PAINT, A BITUMEN VARNISH OR AN EPOXY RESIN.APPLICATION TO BURIED CAST-IRON PIPELINES. |
