What Is A Sanitary Valve? How Is Its "sanitation" Reflected?

Sanitary valves, as the name suggests, are designed specifically for fluid systems with stringent hygienic requirements. Their biggest difference from ordinary industrial valves lies in their design, materials, manufacturing processes, and even maintenance, all centered around the core goal of preventing contamination.

1. Material: From "Rust-Free" to "Preventing Sedimentation"
The cast iron and carbon steel commonly used in ordinary valves are completely inadequate for sanitary applications—they either corrode and dislodge easily or release heavy metal ions into the fluid. The standard materials for sanitary valves are 304 stainless steel (0Cr18Ni9) or 316L stainless steel (00Cr17Ni14Mo2):
- 304 stainless steel: Offers excellent corrosion resistance, suitable for contact with neutral fluids (such as milk and drinking water);
- 316L stainless steel: Contains molybdenum, offering enhanced resistance to chloride ion corrosion, making it the preferred choice for pharmaceuticals and acidic foods (such as tomato juice and vinegar). In more stringent applications (such as biopharmaceuticals), Hastelloy or titanium alloys are also used to ensure that no contaminants are generated, even in high-temperature, high-pressure, or highly corrosive environments.

2. Structure: "No dead angles" is the highest principle.
Bacteria and microorganisms love to hide in crevices, recesses, or threads. The structural design of sanitary valves is designed to "block their escape routes":

- Flow path design: Use a "straight-through" or "streamlined" flow path to prevent fluid from being trapped within the valve.

- Sealing method: Forgo the "packing seal" of ordinary valves (which easily harbors contaminants) and instead use an "O-ring seal" made of food-grade silicone or fluororubber. The seal must be fully embedded in the groove, with no protruding parts.

- Connection method: Prefer quick couplings or welding (such as automatic argon arc welding) over threaded connections, as the gaps between threads are a "paradise" for microorganisms.

- Removable components: The valve core, seat, and seals can be quickly disassembled for easy cleaning and disinfection (such as steam sterilization).

3. Surface Treatment: So Smooth That "Microorganisms Can't Survive"
If you examine the inner surface of a sanitary valve under a microscope, you'll find it's mirror-smooth—thanks to mechanical or electrochemical polishing. Industry standards stipulate that the surface roughness (Ra value) of sanitary valves must be ≤ 0.8μm (some high-end products even require ≤ 0.4μm), equivalent to 1/100th the diameter of a human hair.
This "ultra-smooth" surface serves two purposes: first, it reduces fluid resistance, preventing fluid from stagnating within the valve; second, it facilitates cleaning—even small residues can be removed with a simple rinse of water or detergent, leaving no "unhygienic corners."