Hygienic valves are valve fittings specifically designed for industries such as pharmaceuticals, food, bioengineering, cosmetics, semiconductors, etc., which have extremely high requirements for cleanliness and hygiene levels. They must comply with international hygiene standards such as 3A, DIN, SMS, ISO, IDF, BPE, FDA, and GMP. 

I. Complete Range of Products 

According to their functions and structural types, sanitary valves are mainly divided into the following major series: 

Ball Valve Series: Includes stainless steel sanitary ball valves, dairy product ball valves, clamp ball valves, non-angled ball valves with retaining balls, two-piece/three-piece ball valves, sanitary quick-connect ball valves, etc. Ball valves are one of the most widely used types, featuring excellent sealing performance and easy operation, and are suitable for quickly cutting off and connecting pipelines. 

Butterfly Valve Series: Includes stainless steel sanitary butterfly valves, three-piece butterfly valves, quick-installation butterfly valves, round screw butterfly valves, pneumatic butterfly valves, sanitary round thread butterfly valves, etc. The butterfly valve has a compact structure, large flow capacity and low resistance, and can be fixed at every 15° position, making it suitable for large-diameter flow regulation. 

Diaphragm Valve Series: This includes stainless steel sanitary diaphragm valves, pneumatic diaphragm valves, U-tube diaphragm valves, membrane type and piston type sanitary diaphragm valves, etc. The most significant feature of diaphragm valves is that the medium is completely isolated from the driving components, achieving zero leakage and no dead corners. 

Check valve series: Includes stainless steel sanitary check valves, welded check valves, etc., which are used to automatically prevent the backflow of media and protect pumps and downstream equipment. 

Stop valve series: Includes sanitary manual stop valves, T-shaped stop valves, etc., which are used in situations where precise control of flow is required. 

Gate Valve Series: It adopts a wedge-shaped elastic gate plate structure, combined with a Stellite cobalt-based hard alloy welded sealing pair. It has strong anti-abrasion ability and is suitable for pipelines containing particles. 

Safety Valve Series: Comprises spring-type, lever-type, and pulse-type safety valves. They are divided into micro-opening type (for liquids) and full-opening type (for gases), and are used for automatic pressure relief protection of pressure vessels and storage tanks in case of overpressure. 

Electromagnetic valve series: Includes diaphragm type and piston type sanitary electromagnetic valves. Both open-type and closed-type are available. The diaphragm type can withstand a pressure of 1.0 MPa, while the piston type can withstand 1.6 MPa. They are highly sensitive and suitable for remote automatic control. 

Regulator and Sampling Valve Series: This includes sanitary regulators for precise flow and pressure regulation, as well as sanitary sampling valves for aseptic sampling and to prevent cross-contamination. They are commonly used in pharmaceutical QC for online testing. 

Valve series: Includes sanitary three-way ball valves, used for switching multiple fluids. 

Special valves: Include anti-mixing valves (with built-in leakage chambers, using vacuum effect to prevent medium mixing), pigging valves, blow-off valves, exhaust valves, filters, etc. 

Expansion by driving mode: All the aforementioned types of valves can be equipped with various driving modes such as manual, pneumatic, electric, and pneumatic-electric combinations, meeting the needs of different levels of automation. 

II. Key Features 

Materials and Sealing 

The main materials are all made of SUS304, SUS304L, SUS316, and SUS316L stainless steel. Among them, SUS316L has the best corrosion resistance and is most widely used in the pharmaceutical and bioengineering fields. The sealing materials include EPDM (triple rubber of ethylene propylene diene monomer), NBR (nitrile butadiene rubber), silicone rubber, PTFE (polytetrafluoroethylene), and VITON (fluorine rubber), which possess acid resistance, alkali resistance, high-temperature resistance, and have small permanent compression deformation, ensuring the reliability of long-term sealing. 

2. Surface Treatment (The Core Feature) 

The inner walls are mechanically polished, with the surface roughness Ra not exceeding 0.8 μm. For high-end products, electro-polishing treatment is adopted, and the surface roughness Ra can reach below 0.2 μm, presenting a mirror-like effect. All surfaces in contact with the medium are designed with trumpet-shaped sealing surfaces, combined with a zero-angle dead space structure, completely eliminating medium residue and effectively preventing bacterial growth. 

3. Connection Methods (Four Main Types) 

The quick-installation (clamp-type) connection method is the most commonly used one, enabling quick assembly and disassembly, significantly reducing the downtime for maintenance. The welding type provides a permanent connection and offers the most reliable sealing. The threaded installation is simple and convenient, suitable for small-diameter pipelines. The flange type is suitable for large-diameter and high-pressure applications. 

4. Key technical parameters 

The working pressure is usually between 0.6 and 1.0 MPa. Some high-pressure models can reach up to 1.6 MPa, and the safety valve can reach 10 bar. The working temperature range is generally from -10°C to +150°C. Some special models can cover from -40°C to 232°C. The nominal diameter ranges from DN10 to DN150 (i.e., 1/4 inch to 6 inches). The product complies with international standards such as DIN, ISO, SMS, 3A, IDF, RJT, BS, BPE, ASME/BPE, etc., and has obtained health certifications such as 3A, EHEDG, FDA, GMP, etc. 

III. Comparison of Characteristics of Major Crops 

The core advantages of the butterfly valve lie in its compact structure, large flow capacity, low resistance, and the use of equal-diameter design. The opening and closing angle can be adjusted between 0 and 90 degrees, and it can be fixed at every 15-degree position. Typical application scenarios include flow regulation in large-diameter pipelines in food and beverage, beer, and dairy production lines. 

The ball valve has excellent sealing performance and is easy to operate. It can achieve rapid cutting-off and connection, with precise control. It is typically used in pharmaceutical, cosmetic and various high-hygiene requirement fluid cutting-off scenarios. 

The most prominent feature of the diaphragm valve is that the medium is completely isolated from the driving components, achieving zero leakage and a design without dead corners. It is also very easy to perform on-site CIP cleaning and SIP steam sterilization. It is typically used in scenarios with extremely high cleanliness requirements, such as biopharmaceuticals, WFI systems for injection water, fermentation tanks, and sterile filtration systems. 

The check valve can automatically prevent the backflow of the medium, effectively protecting the pump and downstream equipment from damage. It is widely used in various sanitary fluid pipeline systems. 

Safety valves automatically release excessive pressure. The main types are spring-type and pulse-type. The micro-opening type is suitable for liquids, while the full-opening type is suitable for gases. They are mainly used for overpressure protection of pressure vessels and storage tanks. 

The electromagnetic valve is highly responsive and supports remote automatic control. It comes in two types: normally open and normally closed. It is widely used in the fluid control systems of automated production lines.