In industrial pipelines, butterfly valves are very common. However, for industries with high requirements for media purity and hygiene, such as food, pharmaceutical, and biotechnology, ordinary butterfly valves are not sufficient, and sanitary butterfly valves are needed. So, what exactly are the differences between these two types of valves? Aohoy Sanitary, a professional valve manufacturer with its website at www.aohoysanitary.com, will explain it for you.
Sanitary Tri Clamp Butterfly valve
The design of ordinary butterfly valves mainly focuses on general - purpose industrial applications. Their internal structures may have some areas where media can accumulate, such as corners or uneven surfaces in the flow path. This is because in applications like water treatment plants or general industrial pipelines, the requirements for media purity and easy cleaning are not as strict. The structure is relatively simple, often aiming to achieve basic functions such as opening, closing, and throttling the flow of media at a lower cost.
Sanitary butterfly valves are designed with a strong emphasis on hygiene. They adopt a "dead - leg - free" design. The inner wall of the valve body and the flow path of the valve are highly polished, typically achieving a surface roughness (Ra value) of less than 0.8μm. This smooth surface minimizes the chance of media residue and the growth of bacteria or other contaminants. Additionally, sanitary butterfly valves are often designed to be compatible with Clean - in - Place (CIP) and Sterilize - in - Place (SIP) systems. This means that the valve can be thoroughly cleaned and sterilized without being disassembled, which is crucial for maintaining a hygienic production environment in industries like food and pharmaceuticals.
For ordinary butterfly valves, materials are selected based on the requirements of the working medium and operating conditions. Common materials include cast iron, carbon steel, and ordinary stainless steel (such as 304 stainless steel). Cast iron and carbon steel are often used in non - corrosive or less - demanding environments, such as in some water supply pipelines or low - pressure gas pipelines. These materials can meet the basic mechanical strength requirements and are relatively cost - effective.
Sanitary butterfly valves are mainly made of high - quality 316L stainless steel. 316L stainless steel has excellent corrosion resistance, especially in the presence of corrosive media that may be encountered in food and pharmaceutical production, such as acidic or alkaline substances. Moreover, it is non - toxic, ensuring that it will not contaminate the media flowing through it. All materials in contact with the media, including sealing materials, must comply with strict food and drug industry standards. For example, sealing materials are often made of food - grade EPDM (ethylene - propylene - diene monomer) or silicone rubber, which have good sealing performance and are safe for contact with food and pharmaceutical products.
The production process of ordinary butterfly valves generally does not require extremely high precision. The inner wall of the valve body may have a relatively rough surface finish, and the welding quality requirements are mainly focused on ensuring the strength and tightness of the structure. There may be some minor gaps or unevenness in the welding parts, which is acceptable in general industrial applications as long as it does not affect the normal operation of the valve.
The production process of sanitary butterfly valves is extremely strict. After the valve body is formed, it undergoes a series of precision processing steps. The inner wall needs to be carefully polished to achieve the required high - smooth surface. Welding is also carried out with high - precision techniques to ensure seamless welding, minimizing the presence of any crevices or protrusions that could trap media. The entire production environment is often kept in a cleanroom or a controlled - environment area to prevent external contamination during the manufacturing process. This high - standard production process ensures that the sanitary butterfly valve meets the strict hygiene requirements of relevant industries.
Ordinary butterfly valves are widely used in various general industrial fields. In the water treatment industry, they are used to control the flow of raw water, treated water, and wastewater in water treatment plants. In the heating and ventilation systems, they can adjust the flow of hot water or air. In the petrochemical industry, they are used in pipelines transporting non - corrosive or slightly corrosive media under normal conditions.
Sanitary butterfly valves are specifically designed for industries with high - level hygiene requirements. In the food and beverage industry, they are used in the production lines of milk, juice, beer, and other products to control the flow of raw materials, semi - finished products, and finished products, ensuring that the products are not contaminated during the production process. In the pharmaceutical industry, they play a crucial role in the manufacturing of drugs, vaccines, and other pharmaceutical products, maintaining the sterility and purity of the media in the pipelines. They are also used in the cosmetics industry, where the quality and safety of products are highly emphasized.
Due to the relatively simple design, less - expensive materials, and less - demanding production processes, ordinary butterfly valves generally have a lower cost. This makes them a cost - effective choice for many general industrial applications where the requirements for hygiene and media purity are not extremely high.
Sanitary butterfly valves are more expensive. The use of high - quality 316L stainless steel and food - grade sealing materials increases the material cost. The complex and high - precision production processes, including precision polishing and cleanroom manufacturing, also add to the production cost. In addition, the need to comply with various strict industry standards often requires additional testing and certification costs. However, considering the importance of maintaining product quality and safety in industries such as food and pharmaceuticals, the higher cost of sanitary butterfly valves is justifiable.
In conclusion, although both ordinary butterfly valves and sanitary butterfly valves are used for pipeline flow control, their differences in design, materials, production processes, application scenarios, and costs are significant. When choosing a butterfly valve, it is essential to consider the specific requirements of the application to ensure the proper function and quality of the pipeline system. Aohoy Sanitary, as a professional valve manufacturer, can provide high - quality sanitary butterfly valves and other sanitary valves to meet the diverse needs of different industries.
