Why does the plumber say galvanized pipe is not good?

The plumber said the galvanized pipe was not good. There is a simple reason. There are two kinds of pipeline corrosion, one is oxidation corrosion and the other is electric corrosion. For buried pipelines, it is mainly electric corrosion. Galvanizing can only prevent oxidation corrosion.

In general, two layers of cold priming oil, two layers of hot asphalt plus cold priming oil plus two layers of hot asphalt, or three layers of four oils are basically used for anticorrosion of fire-fighting galvanized pipes, that is, asphalt oil and so on. See the instructions for details.

1. The galvanized layer outside the galvanized pipe is an antirust layer, not an anticorrosive layer, so the galvanized pipe should be treated with anticorrosive treatment when buried (building code: GB500 15-2003- 3.4.3).

2. The anticorrosion of pipelines shall meet the requirements of (Construction Code: GB50242-2002-9.2.6).

Not only galvanized pipes, but also welded steel pipes should be treated in this way to strengthen anti-corrosion (that is, three fabrics and four oils).

There is a simple reason. There are two kinds of pipeline corrosion, one is oxidation corrosion and the other is electric corrosion. For buried pipelines, it is mainly electric corrosion. Galvanizing can only prevent oxidation corrosion.

Distinguish the quality of galvanized pipe

1. Generally speaking, the defective galvanized pipe is in a folded state, and the appearance of the folded galvanized pipe is the main reason for this folding line. This shortcoming often runs through the longitudinal direction of the whole product, and the reason for folding may be that some manufacturers who fail to meet the requirements are too pursuing high efficiency, which will lead to this folding under the condition of excessive reduction. If the folded galvanized pipe is used for bending,

2. Some defective galvanized pipes still have pits on the surface, which may be caused by the irregular and uneven surface of the production equipment used by galvanized pipe manufacturers. Such defective galvanized pipes often make the production equipment overrun, so there will be pits on the appearance.

3, and often poor quality galvanized pipes are easy to scar, because the raw materials produced by poor quality galvanized pipes are mostly uneven, and the magazines contained in them are relatively high. Moreover, the production equipment of low-quality galvanized pipe manufacturers is mostly very simple, which is prone to problems such as steel sticking, so that scars will appear on the galvanized pipes produced.