How to identify genuine and fake hot-dip galvanized seamless steel pipes with the naked eye

Nowadays, there is a so-called hot-dip galvanized fluid pipe on the market, also known as de-galvanized seamless pipe, which is actually a treated high-frequency welded pipe. The original weld is either planed or ground off with special equipment before galvanizing. Now the identification of this kind of pipe will come out and share with you:

1) All planed or ground will leave traces, some are obvious;

2) hot-dip galvanized to seamless pipes are 6 meters, 9 meters or 12 meters fixed length, genuine hot-dip galvanized seamless steel pipe fixed length is very small, because the fixed length factory to increase a lot;

3) this kind of pipe manufacturers because of fear of responsibility, their quality certificates are fluid pipes and dare not say it is seamless steel pipe;

4) to see if the wall thickness is uniform, because the seamless steel pipe is made of round steel hot-rolled perforation, so the general seamless steel pipe wall thickness deviation (with the continuous improvement of technology, the wall thickness deviation of seamless steel pipe is getting smaller and smaller, but there are still some) Although the welded pipe is treated with welding bars or heat expansion procedures, but because his raw material is strip steel, so his wall thickness is very uniform.

how to distinguish hot and cold galvanized steel pipe from the appearance, Hubei galvanized steel pipe

Do you often have to distinguish some pipe fittings are cold galvanized or hot galvanized? Of course, many people will say that it is not clear to send it to the quality inspection agency, but I personally think that the traditional inspection method is not only a waste of time but also a waste of money. Here is a way to identify these two kinds of pipe fittings:

1, the difference is as follows:

Appearance: Hot-dip galvanizing looks concave and convex, slightly darker; cold galvanizing looks smooth and bright;

Thickness: hot-dip galvanizing thick, cold galvanizing thin;

Inner hole: hot-dip galvanizing inner hole has coating: cold galvanizing inner hole only two ends;

Corrosion resistance: hot-dip galvanizing high: cold galvanizing low;

Identification: hot-dip galvanizing at both ends with blue ink printed hoop, the whole body has execution standards and specifications Model: cold galvanizing without.

2, the price of cold galvanizing is correspondingly lower

This is an empirical thing, but to observe whether the galvanizing layer is flat and uniform is an important item, and to look at the quality inspection report and the supporting documents of the appearance manual. If you feel that the document cannot be explained, then I suggest hitting the pipe with a hammer or something to see if the galvanizing layer will fall off. If it falls off, then nine times out of ten it is cold plated.

Source: Hubei AD Building Materials Co., Ltd. Welcome to share!