DE612125C - Methods of protecting buried pipes, e.g. Iron or cement pipes, against corrosion - Google Patents

Description

Procedure for the protection of underground pipes, e.g. iron or cement pipes, against corrosion As corrosion protection for iron, galvanized iron and cement pipes, those in aggressive soils such as peatland, acidic, salty and sulphurous industrial soil are laid, the most diverse materials are proposed and used came. Attempts have been made to replace the excavated pipe channels into which the Pipes to be protected are laid with crushed limestone or with slaked To fill in lime at the level of the pipe, so that the aggressive soil does not touch; n; g mix comes into the pipe and the soil acids or the like are neutralized. This procedure has proven, as tests show, to be unsuitable. Proven unsuitable as well The painting of the pipes with lime and cement milk suggested in the literature.

Also the processes generally in use, the pipes by painting. with bitumen, chlorinated rubber, etc. or by wrapping with tar To protect or bitumen-soaked bandages offer despite the considerable costs no sufficient certainty that a pipeline is now in all parts for Is protected for years. While transporting; Unloading and laying of the pipes, special with socket casting with lead, these protective compounds are easily damaged and thereby exposed the iron. It has now been shown in practice that everyone, including the The smallest damage enables the attack at these points and thus the destruction of the whole pipe section.

A simple method was found, buried pipes for decades to protect against corrosion. This process consists of embedding the pipes in so-called water glass sludge. The waterglass sludge is the filtration residue the production of liquid water glass from the molten piece of glass. He exists Essentially composed of calcium and aluminum hydrosilicate with about 10% (on the dry matter calculated) freezes ground piece glass. So far it has been considered an annoying waste product, for which an area of application did not exist, poured onto the heaps.

The procedure is carried out as follows: On the floor of the victim An approximately 5 to 10 cm thick waterglass sludge is tamped into the pipe channel, then relocated the raw. Then the pipe is covered with water glass mud and the Mass tamped down. The soil is placed on top of this embedding in the usual way.

For zoo m laid, 25o mm thick cast iron pipes were 3o Tons of mud related. After four years there was no attack whatsoever the industrial soil, which was heavily contaminated by sulphate and sulphite residues, determine, while unprotected, by bitumen bandages and Pipes protected by white lime showed severe pitting - yes partly rusted through was. The pipes laid in the water glass slurry were bare and smooth and showed at no single test point even the beginnings of. Erosions. The water glass sludge In contrast to white lime mud, which becomes rock-hard and cracked, easy to use remove.

Water glass by itself or time addition of pigments or the residue from the treatment of bauxite with alkalis in connection with oils are already for anti-rust paints have been used. But these are not emd-laid ones Pipes still around an embedding compound of the type claimed; the addition to use a previously useless waste product provides an extremely reliable protection against corrosion for underground pipes.

Claims (1)

PATENT CLAIM: Process for the protection of underground pipes, e.g. B .. Lisen or cement pipes, against corrosion by embedding in alkaline reacting 2dassen, characterized in that the filtration residues are used as embedding agents from water glass production can be used.