Stainless steel pipe fittings belong to a kind of pipe fittings, it is made of stainless steel so called stainless steel pipes. Stainless steel pipe fittings include: stainless steel elbow, stainless steel tee, stainless stainless steel four, the size of the head, and so on.
Reducing pipe necking, is to heat one end of the stainless steel large diameter pipe to the red hot state, With a hammer, make its diameter reduced, become a big one small pipe, commonly known as “size head,” or “change diameter.” Sometimes the diameter difference between the two ends of the stainless steel head is too large, the large diameter of the pipe at one end of the first cut off a few curved triangular pieces, Then reheat to red-hot state, with a hammer, so that its cut off the gap and then close together to form a joint, and the formation of the small port full circle, the seam welding. According to the size of reducing diameter pipe, it can be divided into one pressing forming or multiple pressing forming. In addition to using steel pipe as raw material to produce size head, some size head can also be produced by stamping process of steel plate. The shape of the drawing die is designed according to the inner surface of the head. The blanking steel plate is stamping and drawing with the die.
In addition to using steel pipe as raw material to produce size head, some size head can also be produced by stamping process of steel plate. Size head (reducer) is used for pipe diameter of a pipe fitting. The forming process of the stainless steel head is usually reduced diameter, expanded diameter or reduced diameter plus expanded diameter. The reducers of some specifications can also be stamped. In the process of reducing / expanding forming the size head, the tube blank with the same diameter at the big end of the diameter head is put into the forming die, and the metal is moved along the die cavity and contracted by pressing along the axial direction of the tube.
Benefits of stainless steel pipe
1, long service life
Stainless steel tubing has the longest service life. From the domestic and foreign stainless steel pipe application status analysis, stainless steel water pipe application life of 100 years, at least there will be 70 years, with the building life as long.
2, strong corrosion resistance
One of the most prominent advantages of stainless steel tubes is their excellent corrosion resistance, because stainless steel can passivate with oxidizers, so it is slightly better than a variety of tubes.
3, good heat resistance and insulation properties
The thermal conductivity of stainless steel pipe is 1 / 25 of copper pipe and 1 / 4 of general steel pipe, which is very suitable for hot water transportation. The most commonly used stainless steels in the hydraulic industry are 316 and 304 stainless steels, which can meet most water treatment and transportation conditions.
4, high compressive strength
304 stainless steel pipe tensile strength is 2 times of steel pipe, plastic pipe 8 to 10 times. The compressive strength of the material determines whether the water pipe is strong and crash-resistant, safe and stable. Safety and stability is the most important standard in building water supply. The probability of leakage of stainless steel pipes is very small under the condition of external force or external factor impact.
304 is a universal stainless steel pipe, it is widely used in the production of good comprehensive performance (corrosion resistance and formability) of equipment and parts. 304 stainless steel pipe is in accordance with the United States ASTM standard produced a stainless steel brand, equivalent to our 0Cr19Ni9 (0Cr18Ni9) stainless steel. 304 chromium 19%, 9% nickel, is the most widely used stainless steel, heat-resistant steel. For food production equipment, general chemical equipment, nuclear energy and so on.
The use of stainless steel pipes and the environment in which they are used should be considered before selecting stainless steel pipe fittings. Such as: decoration generally use welded pipe, fluid transmission generally use seamless pipe, Medical or kitchen to use sanitary stainless steel pipe, pressure use thick wall pipe, generally indoor use 200 series material can, outdoor use 304 material, and in acid and alkali places or coastal areas generally use 316 above material.
In the selection of steel pipe to determine the material standards. To 304 material as an example: a, from the price analysis, if 304 material stainless steel pipe material even lower than the common price of 201 material on the market, to carefully identify, may be other material posing; B, identify whether the tube surface stamped material “304” words, and to obtain factory quality certificate as evidence; C, available acidic reagent test, 30 seconds later material 304 does not change color, 201 black; D, bulk purchase can take samples sent to the national authoritative testing center for component analysis.
Watch the color of the outer surface and inner wall of the tube is bright and smooth, whether the thickness is uniform or rough. General welded pipe this basic need not check, and seamless steel pipe is cold drawn or hot rolled production, Improper operation in the production process easy to produce uneven thickness, pipe surface cracks and other phenomena, and the surface roughness is generally seamless pipe not polished, if the appearance of no special requirements do not affect the use.
Should choose to buy by the quality and technical supervision bureau assessment to excellent products. Having a long use of testimonials and good word of mouth among customers is a direct and effective way to buy.
Rolling pipe often appear within the heavy skin, pitting, and rolling green line, in general these can not be avoided, also basically does not affect the use, but must choose as little as possible in the purchase, especially to check the inner surface.