Precautions for purchasing seamless stainless steel pipes

Precautions for purchasing and selecting seamless stainless steel pipes are as follows:

Clearly define the use requirements:

1. Purpose
Determine the performance requirements of the required steel pipe according to the specific purpose. For example, for fluid transportation, corrosion resistance and sealing should be considered; for mechanical structures, strength and toughness should be considered. For example, in the petrochemical industry, if it is used to transport corrosive media, highly corrosion-resistant stainless steel seamless pipes are required; and in building structures, there are high requirements for strength and seismic resistance.

2. Use environment

Consider the characteristics of the use environment, such as temperature, humidity, pH, etc. In high temperature environments, high temperature resistant materials need to be selected; in highly corrosive environments, such as the seaside or chemical workshops, materials with good corrosion resistance should be selected, such as 316 stainless steel, which is often used in marine environments or highly corrosive occasions.

Check the quality of the material:

1. Material composition
Understand the material number of stainless steel, common ones are 304, 316, etc., and the performance of different materials is different. You can verify whether the material composition meets the requirements by checking the material certificate or using professional testing methods (such as spectrometer analysis, potion testing, etc.). For example, 304 stainless steel contains 18% - 20% chromium and 8% - 10.5% nickel. If the nickel content is too low, it may affect corrosion resistance.

2. Quality certificate
Check the product quality certificate, check the manufacturer's name, production date, production (furnace) batch number, manufacturing standards, factory inspection items and related test data, inspection special stamp and other information, to ensure that the product source is reliable and the quality is guaranteed.

Observe the appearance quality:

1. Surface defects
The surface of high-quality stainless steel seamless pipes (SS seamless pipe) should be smooth, free of cracks, scratches, pits, folds, scars and other defects. It can be observed with the naked eye or with the help of a magnifying glass. If there are any of the above problems, it may affect the performance and service life of the steel pipe.

2. Dimensional accuracy
Measure the outer diameter, wall thickness, length and other dimensions of the steel pipe to ensure that the dimensional deviation is within the standard allowable range. If the outer diameter and wall thickness are uneven, it may cause installation difficulties or affect the structural strength. Roll the steel pipe on a flat ground and observe the size and change of the gap between the steel pipe and the ground. The two end faces of the qualified seamless steel pipe should be perpendicular to the axis and the cut should be free of burrs.

3. Surface treatment
Check the surface treatment of the steel pipe according to the needs, such as whether it has been pickled, passivated and other treatments, and whether the effect after treatment meets the requirements. A complete passivation film should be formed on the surface of the steel pipe after pickling and passivation to improve corrosion resistance.

Verify performance indicators:

1. Corrosion resistance
The corrosion resistance of the steel pipe can be tested by methods such as salt spray test. Place the steel pipe sample in a salt spray environment and observe the corrosion over a certain period of time. This performance is particularly important for steel pipes used in harsh corrosive environments.

2. Mechanical properties
Including indicators such as tensile strength, yield strength, and elongation. These properties determine the strength and deformation capacity of the steel pipe during use, and can be tested by professional testing agencies to ensure that it meets the design and use requirements.

Choose a reliable manufacturer:

1. Reputation and reputation
Choose a manufacturer with good reputation and reputation, which can be understood by checking the manufacturer's qualification certificate, customer evaluation, industry recognition, etc. Reliable manufacturers have advanced production equipment and technology, strict quality control, and more guaranteed product quality.

2. After-sales service

High-quality manufacturers will provide comprehensive after-sales services, such as product quality assurance, technical support, return and exchange policies, etc. Understand the manufacturer's after-sales service policy before purchasing so that problems encountered during use can be solved in a timely manner.

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