The roundness of the eccentric reducer (eccentric head) shall not be greater than 1% of the outer diameter of the corresponding end, and the deviation is allowed to be + 3mm; the center line of both ends of the concentric tapered pipe shall be coincident, and the allowable deviation of its eccentricity value is + 5mm.

The quality of the eccentric reducer shall be in accordance with the current national standard "seamless steel welded pipe fittings", GB/T 12459-2005, and shall meet the following requirements:

1) the eccentric eccentric tube shall not be cracked and heavy in appearance, and the wall thickness shall be larger than the thickness of the big diameter end pipe section.

2) the roundness of the eccentric reducer shall not be greater than 1% of the outer diameter of the corresponding end, and the deviation is allowed to be + 3mm; the center line of both ends of the concentric tapered pipe shall be coincident, and the allowable deviation of its eccentricity value is + 5mm.

3) the deviation of the dimensions of the eccentric reducer shall be in accordance with the provisions of the table.

Eccentric reducer (eccentric big head) material is a low carbon structure steel, alloy element content is less, generally below 3%. Eccentric different diameter pipe (eccentric reducer) in the actual production in which to add different elements for different functions and intensity, with certain production standards and methods to add, has certain performance in use. The characteristics of eccentric different diameter pipe is made of carbon steel was significantly higher than the same carbon content, with good toughness and ductility and good weldability and corrosion resistance. In order to improve the performance of the steel, adding other alloying elements in steel on the basis of, such as silicon, manganese, chromium, nickel, tungsten, vanadium, titanium, etc., this is called steel alloy steel.

Eccentric different diameter pipe (eccentric reducer) by adding alloy elements are different, with different properties, such as high wear resistance, corrosion resistance, low temperature resistance and high magnetic properties. Good special alloy steel divided by use of alloy structural steel, alloy tool steel and special steel. For safety, hygiene and environmental protection, economic and eccentric different diameter pipe, thin-walled pipe and new development of reliable, simple and convenient connection method, so it has more other pipe irreplaceable advantages, engineering application will be more and more, use will be more and more popular, promising.

Eccentric different diameter pipe (eccentric head) of the necking forming process is tube with different diameter pipe is equal to the diameter of the big end in forming model, by pressing the tube billet along the axial direction of the metal mould cavity movement along the contraction and forming.

Eccentric different diameter pipe (eccentric reducer) scale: GB American Standard British standard and non-standard stamping pressure, in addition to the use of steel as raw material to produce different diameter pipe, steel plate by stamping process can also be used for production of the Department specifications of different diameter pipe.