GMP (Good Manufacturing practice for milk products, Good Manufacturing Practice for Dairy Products) is the abbreviation of Dairy Production Quality Management Practice and is an advanced and scientific management method for dairy production. In the GMP chapter, requirements are put forward for the materials and design of clean pipes, that is, “Equipment in direct contact with dairy products should be smooth and without dents or cracks to reduce the accumulation of food debris, dirt and organic matter”, “All production Equipment should be designed and constructed to be easily cleaned and disinfected and to be easily inspected.” Clean pipelines have the characteristics of independent systems and strong professionalism. Therefore, this article elaborates on the selection of clean pipeline materials, surface requirements for contact with dairy products, pipeline system welding requirements, self-draining design, etc., aiming to improve dairy enterprises and construction The unit’s understanding of the importance of clean pipeline installation and treatment.
Although GMP puts forward strict requirements for the materials and design of clean pipelines, the phenomenon of heavy equipment and light pipelines is still common in China’s dairy industry. As an important part of the dairy production process, clean pipeline systems still receive little attention. Not enough is still a weak link restricting the improvement of dairy product quality. Compared with the relevant standards of the foreign dairy industry, there is still a lot of room for improvement. At present, the American 3-A hygiene standards and the European Hygienic Engineering Design Organization standards (EHEDG) are widely used in the foreign dairy industry. At the same time, dairy factories under the Wyeth Group in the United States that insist on dairy factory design that meets pharmaceutical standards have adopted the ASME BPE standard as a guiding specification for the design and installation of dairy factory equipment and pipelines, which will also be introduced below.
01
U.S. 3-A health standards
The American 3-A standard is a recognized and important international health standard, initiated by the American 3-A Health Standards Company. The American 3A Sanitary Standards Corporation is a non-profit cooperative organization dedicated to promoting the hygienic design of food production equipment, beverage production equipment, dairy equipment and pharmaceutical industry equipment, which mainly promotes food safety and public safety.
The 3-A Hygiene Standards Company was jointly organized by five different organizations in the United States: the American Dairy Producers Association (ADPI), the International Federation of Food Industry Suppliers (IAFIS), and the International Federation for Food Sanitation Protection (IAFP) , the International Dairy Products Federation (IDFA), and the 3-A Sanitary Standards Marking Council. 3A’s leadership includes the U.S. Food and Drug Administration (FDA), the U.S. Department of Agriculture (USDA), and the 3-A Steering Committee.
The U.S. 3-A sanitary standard has very strict regulations on clean pipeline systems, such as in the 63-03 standard for sanitary pipe fittings:
(1) Section C1.1, pipe fittings in contact with dairy products should be made of AISI300 series stainless steel, which is corrosion-resistant, non-toxic and will not migrate substances into dairy products.
(2) Section D1.1, the surface roughness Ra value of stainless steel pipe fittings in contact with dairy products should not be greater than 0.8um, and dead corners, holes, gaps, etc. should be avoided.
(3) Section D2.1, the welding surface of stainless steel in contact with dairy products should be seamless welded, and the roughness Ra value of the welding surface should not be greater than 0.8um.
(4) Section D4.1, pipe fittings and dairy contact surfaces should be self-draining when properly installed.
02
EHEDG Hygienic Design Standard for Food Machinery
European Hygienic Engineering & Design Group European Hygiene Engineering Design Group (EHEDG). Founded in 1989, EHEDG is an alliance of equipment manufacturers, food industry companies, and public health institutes. Its main goal is to set high cleanliness standards for the food and packaging industry.
EHEDG targets food processing equipment that should have a good hygienic design and be easy to clean to avoid microbial contamination. Therefore, the equipment needs to be easy to clean and protect the product from contamination.
In EHEDG’s “Sanitary Equipment Design Guidelines 2004 Second Edition”, the piping system is described as follows:
(1) Section 4.1 generally should use stainless steel with good corrosion resistance;
(2) When the pH value of the product in Section 4.3 is between 6.5-8, the chloride concentration does not exceed 50ppm, and the temperature does not exceed 25°C, AISI304 stainless steel or AISI304L low carbon steel that is easy to weld is usually selected; if the chloride concentration If it exceeds 100ppm and the operating temperature is higher than 50℃, materials with stronger corrosion resistance must be used to resist pitting and crevice corrosion caused by chloride ions, thereby avoiding chlorine residues, such as AISI316 stainless steel, and low carbon steel. AISI316L has good welding performance and is suitable for piping systems.
(3) The inner surface of the piping system in Section 6.4 must be self-drainable and easy to clean. Horizontal surfaces should be avoided, and the inclination angle should be designed to avoid accumulation of residual water.
(4) On the product contact surface in Section 6.6, the welding joint must be seamless and flat and smooth. During the welding process, inert gas protection must be used inside and outside the joint to avoid oxidation of the metal due to high temperature. For piping systems, if construction conditions (such as space size or working environment) permit, it is recommended to use automatic orbital welding as much as possible, which can stably control the welding parameters and weld bead quality.
03
American ASME BPE standard
ASME BPE (American society of mechanical engineers, Bio Processing Equipment) is a standard developed by the American Society of Mechanical Engineers to regulate the design, materials, manufacturing, inspection and testing of bioprocessing equipment and pipelines and their ancillary components.
The standard was first published in 1997 to achieve uniform standards and acceptable quality levels for production equipment used in products in the biopharmaceutical industry. As an international standard, ASME BPE fully complies with the relevant laws and regulations of my country’s GMP and the US FDA. It is an important specification used by the FDA to ensure production. It is an important standard for material and equipment manufacturers, suppliers, engineering companies and equipment users. A non-mandatory standard that is jointly sponsored and developed and revised periodically.
3-A, EHEDG, ASME BPE health certification standard marks
In order to ensure the production of highly clean products and reduce the risk of product contamination, the ASME BPE standard has a specific description of automatic welding technology. For example, the 2016 version has the following provisions:
(1) SD-4.3.1(b) When stainless steel pipes are used, 304L or 316L material is generally selected. Automatic orbital welding is the preferred method of pipe joining. In the clean room, the pipe components are made of 304L or 316L material. The owner, construction and manufacturer need to reach an agreement on the pipe connection method, inspection level and acceptance standards before installation.
(2) MJ-3.4 pipeline welding construction should use orbital automatic welding, unless size or space does not allow it. In this case, hand welding can be performed, but only with the consent of the owner or contractor.
(3) MJ-9.6.3.2 After automatic welding, at least 20% of the internal weld beads must be randomly inspected with an endoscope. If any unqualified weld bead appears during the welding inspection, additional inspections must be made according to the requirements of the specification until it is acceptable.
04
Application of international dairy industry standards
The 3-A hygiene standard was born in the 1920s and is an international standard used to standardize the hygienic design of equipment in the dairy industry. Since its development, almost all dairy companies, engineering companies, equipment manufacturers, and agents in North America have used it. It is also generally accepted in other parts of the world. Companies can apply for 3-A certification for pipes, pipe fittings, valves, pumps and other sanitary equipment. 3-A will arrange evaluators to conduct on-site product testing and enterprise evaluation, and issue a 3A health certificate after passing the review.
Although the European EHEDG health standard started later than the U.S. 3-A standard, it has developed rapidly. Its certification process is more stringent than the U.S. 3-A standard. The applicant company needs to send certification equipment to a specialized testing laboratory in Europe for testing. For example, in the test of a centrifugal pump, only when it is concluded that the self-cleaning ability of the pump is at least no less than the self-cleaning ability of the connected straight pipeline, can the EHEDG certification mark be obtained for a specified period of time.
The ASME BPE standard has a history of nearly 20 years since its establishment in 1997. It is used in almost all large biopharmaceutical industries and engineering companies, equipment manufacturers, and agents. In the dairy industry, Wyeth, as a Fortune 500 company, its dairy factories have adopted ASME BPE standards as guiding specifications for the design and installation of dairy factory equipment and pipelines. They have inherited the production management concepts of pharmaceutical factories and adopted automatic welding technology to build advanced dairy processing production line.
Automatic welding technology improves dairy quality
Today, as the country pays increasing attention to food safety, the safety of dairy products has become a top priority. As a supplier of dairy factory equipment, it is the responsibility and obligation to provide high-quality materials and equipment that help ensure the quality of dairy products.
Automatic welding technology can ensure the consistency of welding without the influence of human factors, and the welding process parameters such as tungsten rod distance, current, and rotational speed are stable. Programmable parameters and automatic recording of welding parameters are easy to meet standard requirements and the welding production efficiency is high. As shown in Figure 3, the pipeline renderings after automatic welding.
Profitability is one of the factors that every dairy factory entrepreneur must consider. Through cost analysis, it is found that using automatic welding technology only requires the construction company to equip an automatic welding machine, but the overall cost of the dairy company will be greatly reduced:
1. Reduce labor costs for pipeline welding;
2. Because the welding beads are uniform and neat, and it is not easy to form dead corners, the cost of daily pipeline CIP cleaning is reduced;
3. The welding safety risks of the pipeline system are greatly reduced, and the enterprise’s dairy safety risk costs are greatly reduced;
4. The welding quality of the pipeline system is reliable, the quality of dairy products is guaranteed, and the cost of product testing and pipeline testing is reduced.
Post time: Dec-19-2023