Please Choose Your Language
You are here: Home / Blogs / What Is Sanitary Stainless Steel Pipe?

What Is Sanitary Stainless Steel Pipe?

Views: 0     Author: Site Editor     Publish Time: 2022-03-15      Origin: Site

Inquire

Sanitary grade (food grade) stainless steel pipes are widely used in many fields and industries such as pharmaceuticals, video, beer, drinking water, biological engineering, chemical engineering, air purification, aviation nuclear industry and other national economic construction. There are a lot of imports every year.

1. Surface analysis of stainless steel

Both the AES method and the SPS method can be used to analyze the surface of stainless steel to determine the corrosion ability of the inner and outer surfaces of stainless steel. The analysis diameter issued by AES is very small, which can be less than 20nm. Its original function is to identify elements. The analytical value of XPS method is about 10μm, which is mainly used to determine the chemical state of elements near the surface.

Scanning the mechanically polished surface of 316 stainless steel that has been exposed to the atmosphere with AES and XPS detectors shows that the most typical analysis depth of stainless steel diamond surface is 15nm, and it provides information about the composition and thickness of the passivation layer. The corrosion resistance and so on.

According to the definition, austenitic stainless steel contains high chromium and nickel, and some contain molybdenum, titanium, etc., generally containing 10.5% or more of chromium and has good corrosion resistance. The corrosion resistance is the result of the protective properties of the chromium-rich passivation layer. The passivation layer is usually 3-5nm thick, or equivalent to 15 atoms thick. The passivation layer is formed during the oxidation-reduction reaction process in which chromium and iron are oxidized. If the passivation layer is damaged, a new passivation layer will be formed quickly and electrochemical corrosion will occur immediately, and deep spots of stainless steel will appear. Corrosion and intergranular corrosion. Passivation corrosion resistance is related to the content of chemical components contained in stainless steel, such as high chromium, nickel and molybdenum, etc. can increase the binding energy potential of the passivation layer, and enhance the corrosion resistance of the passivation layer; and use it with the inner surface of the stainless steel pipe. The fluid medium is related.

2. Surface corrosion of stainless steel pipe

(1) The passivation layer on the surface of stainless steel is easily destroyed in the CI-containing medium, because the Ci-oxidation potential is relatively large. If the passivation layer is only on the metal, the printed layer will continue to corrode. In many cases, the passivation layer is only damaged in a local area of the metal surface. The effect of corrosion is to form small holes or pits. The small pits that are randomly distributed on the material surface are called pitting corrosion. The pitting corrosion rate increases with increasing temperature and increases with increasing concentration. The solution is to use ultra-low or low-carbon stainless steel (such as 316L or 304L)


(2) The passive warp layer on the surface of austenitic stainless steel is easily destroyed during manufacturing and welding. When the heating temperature and heating speed during manufacturing and welding are in the stainless steel sensitization temperature region (about 425-815°C), the supersaturated carbon in the material will first precipitate at the grain boundary and combine with chromium to form chromium carbide and lose chromium. As a result, the chromium content of the grain boundary continuously decreases with the continuous precipitation of chromium carbide, forming a so-called chromium-depleted zone, which weakens the potential energy and reduces the corrosion resistance of the passivation layer. When in contact with corrosive media such as Ci- in the medium, it will cause micro-current corrosion. Although the corrosion is only on the surface of the grains, it quickly penetrates into the interior to form intergranular corrosion. Especially the stainless steel pipe is more obvious in the welding treatment part.

(3) Stress corrosion cracking: it is the combined effect of static stress and corrosion that causes cracks and metal embrittlement. The environment for stress corrosion cracking is usually quite complex. Not only the tensile stress, but the combination of this stress and the residual stress in the metal due to fabrication, welding, or heat treatment.


3. Production process of sanitary welded stainless steel pipe

Uncoiling-deburring-forming-welding (gas protection box)-inner leveling-welding seam grinding-pipe cleaning-bright annealing-fine sizing-cutting

It is recommended to use the precision stainless steel sanitary fluid pipe production line of Hangao Tech (SEKO Machinery). Since the steel strip is directly used for welding after forming, the tolerance and ellipticity of the pipeline can be well controlled, and the process of cold drawing can be omitted.


There are several key equipment in production:

(1) Internal leveling equipment: It can be repeatedly pressed back and forth through the roller and the built-in mandrel to flatten the remaining height of the welding seam, so that the welding seam and the base material are more closely aligned and natural transition, making the inner tube wall smoother and reducing the pipeline Residues within. During internal polishing and external polishing, it can also reduce the number and intensity of polishing and reduce loss.

(2) Protective gas bright annealing furnace: It consists of two parts, the bright annealing furnace body and the cooling water jacket.

Bright annealing furnace body: The main structure is a circular section induction heating furnace, which adopts the heating method of induction heating coils, so that the entire pipe section can be heated in all directions. The protective gas not only acts as a barrier to the air, but also serves as a circulating cooling air. Compact structure, safe operation, reliable control and convenient maintenance. The temperature difference in the furnace is controlled within ±1-2℃.

Manufacturers can choose to use ammonia decomposition equipment to make protective gas or directly use canned gas according to their actual conditions.

Welcome to Inquire Us!

Iris Liang

E-mail: sales3@hangaotech.com

Mobile phone: +86 13420628677

QQ: 845643527

Wechat/ Whatsapp: 13420628677

Skype: +86 13420628677

Related Products

Every time the finishing tube is rolled, it must go through the process of solution treatment. Ta ensure that the performance of the steel pipe meets the technical requirements. and to provide guarantee for the post-process processing or use. Bright solution treatment process of ultra-long seamless steel pipe has always been a difficulty in the industry.

Traditional electric furnace equipment is large,covers a large area, has high energy consumption and large gas consumption, so it is difficult for realize bright solution process. After years of hard work and innovative development, the use of current advanced induction heating technology and DSP power supply. Precision control of heating temperature to ensure that the temperature is controlled within t2C,to solve the technical problem of inaccurate induction heating temperature control. The heated steel pipe is cooled by "heat conduction"in a special closed cooling tunnel, which greatly reduces the gas consumption and is more environmentally friendly.
$ 0
$ 0
Explore the versatility of Hangao's Stainless Steel Coil Tube Production Line. Tailored for various applications, from industrial processes to specialized manufacturing, our production line guarantees the seamless fabrication of high-quality stainless steel coil tubes. With precision as our hallmark, Hangao is your trusted partner for meeting diverse industry requirements with excellence.
$ 0
$ 0
Embark on a journey of hygiene and precision with Hangao's Stainless Steel Fluid Tube Production Line. Tailored for sanitary applications in pharmaceuticals, food processing, and more, our cutting-edge machinery ensures the highest standards of cleanliness. As a testament to our commitment, Hangao stands out as a manufacturer where tube production machines boast exceptional cleanliness, meeting the stringent requirements of industries that prioritize purity in fluid handling systems.
$ 0
$ 0
Explore the myriad applications of titanium tubes with Hangao's Titanium Welded Tube Production Line. Titanium tubes find critical utility in aerospace, medical devices, chemical processing, and more, owing to their exceptional corrosion resistance and strength-to-weight ratio. As a rarity in the domestic market, Hangao takes pride in being a stable and reliable manufacturer for titanium welded tube production lines, ensuring precision and consistent performance in this specialized field.
$ 0
$ 0
Dive into the realm of precision with Hangao's Petroleum and Chemical Tube Production Line. Crafted for the rigorous demands of the petroleum and chemical industries, our production line excels in manufacturing tubes that meet the stringent standards required for transporting and processing crucial materials in these sectors. Trust Hangao for reliable solutions that uphold the integrity and efficiency vital to petroleum and chemical applications.
$ 0
$ 0
Experience the epitome of technological advancement with Hangao's Laser Stainless Steel Welded Tube Production Line. Boasting accelerated production speeds and unparalleled weld seam quality, this high-tech marvel redefines stainless steel tube manufacturing. Elevate your production efficiency with laser technology, ensuring precision and excellence at every weld.
$ 0
$ 0

If Our Product Is What You Want

Please get in touch with our team immediately to answer you with a more professional solution
WhatsApp:+86-158-1561-9854 
Tel: +86-139-2821-9289 
E-mail: sales6@hangaotech.com 
Add: No. 23 Gaoyan Road, Duyang Town, Yun 'anDistrictYunfu City. Guangdong Province

Quick Links

About Us

Login & Register

Guangdong Hangao Technology Co., Ltd. is China's only one with high-end precision industrial welded pipe production line full set of equipment manufacturing capabilities.
Leave a Message
Contact Us
Copyright © 2023 Guangdong Hangao Technology Co., Ltd. All Rights Reserved. Support by leadong.com | Sitemap. Privacy Policy