Concept and characteristics of low temperature seamless steel pipe:
Low-temperature seamless steel pipe is a pipe material specially used to transport fluid or gas in low-temperature environments. It has the following advantages and features:
1. It has good low temperature resistance and can operate stably for a long time in extremely low temperature environments below -196°C;
2. It has the characteristics of high pressure resistance and high precision, and is suitable for occasions with high pressure and high precision requirements;
3. Because it is a seamless steel pipe, its inner surface is smooth, the resistance is small, and the fluid transportation efficiency is high;
4. It has excellent corrosion resistance and can adapt to a variety of chemical media and power gas environments.
The most common standard for low temperature seamless pipe is
ASTM A333. ASTM A333 low temperature seamless carbon steel pipe is a steel pipe material with excellent quality and wide application range. Although the price is higher, it has better performance in low temperature conditions. Therefore, when selecting steel pipe materials, its application fields and performance requirements should be fully considered.
ASTM A333 Gr6 cryogenic pipe is a kind of industrial pipe, suitable for seamless steel pipes for -45℃~-195℃ low-temperature pressure vessel pipes and low-temperature heat exchanger pipes.
Impact Test:
Low-temperature carbon steel pipes are supplied in normalized conditions and the Charpy impact test is always executed at specific temperatures to ensure the compliance of the products to the temperature range set by the standard (carbon steel temperature limit for A333 pipes).
Grade
|
F°
|
C°
|
ASTM A333 Grade 1
|
-50
|
-45
|
ASTM A333 Grade 3
|
-150
|
-100
|
ASTM A333 Grade 4
|
-150
|
-100
|
ASTM A333 Grade 6
|
-50
|
-45
|
ASTM A333 Grade 7
|
-100
|
-75
|
ASTM A333 Grade 8
|
-320
|
-195
|
ASTM A333 Grade 9
|
-100
|
-75
|
ASTM A333 Grade 10
|
-75
|
-60
|
Mechanical Tests:
The mechanical testing on low-temperature carbon steel pipes shall be executed as follows:
transverse/longitudinal tension/flattening/hardness/bend: tests to be made on 5% of the pipe from each treated lot. For smaller lots, at least one pipe has to be tested. For material heat treated by the continuous process, tests shall be made on a sufficient number of pipe to constitute 5% of the lot, but in no case less than 2 pipes.
Hydrostatic/ impact/one notched bar impact: shall be made from each heat represented in a heat-treatment load on specimens taken from the finished pipe.
How to use low temperature seamless steel pipe?
1. Purchase
When purchasing low-temperature seamless steel pipes, you need to select the corresponding specifications, pressure levels and materials according to the specific use environment and needs. Before purchasing, you need to understand its basic parameters and performance indicators to avoid purchasing steel pipes that do not meet the requirements.
2. Check
Before installation, the steel pipe needs to be inspected, including inspection of appearance, wall thickness, length, diameter, etc., to ensure that the steel pipe meets the installation requirements.
3. Installation
During installation, relevant installation requirements and procedures should be followed to ensure that the installation is stable, safe and reliable. At the same time, attention should be paid to the anti-corrosion and anti-shock measures of steel pipes to avoid problems during use.
4. Maintenance
The maintenance of low-temperature seamless steel pipes mainly includes anti-corrosion, anti-shock and other aspects. Inspection and maintenance of steel pipes should be strengthened at ordinary times to ensure that they can maintain stable performance and condition during long-term use.
Things to note when using low-temperature seamless steel pipes:
1. Purchase strictly according to the usage environment and requirements to avoid problems such as inconsistent specifications and inappropriate materials;
2. During the installation process, attention should be paid to anti-corrosion and shock-proof measures to ensure safety and reliability;
3. During use, you need to always pay attention to its operating status and pressure changes, and perform timely maintenance and upkeep. At the same time, it is necessary to avoid excessively high or low temperature, pressure, etc. to ensure its normal use.
In summary, low-temperature seamless steel pipes have great advantages and application value in adapting to transporting fluids or gases in low-temperature environments. However, they need to be carefully selected and inspected before use, and operated and maintained in strict accordance with the usage requirements and precautions. , ensuring its long-term stable operation.
