CF8M is the marking code of valve material, which means that the valve body is made of stainless steel castings under the ASTM A351 standard, corresponding to 316 stainless steel (SS316), which is mainly used in industrial scenarios with high corrosion resistance requirements. Its core meaning includes the dual definition of material properties and process standards:
1. Definition of material properties
Corresponding relationship of chemical composition
CF8M ≡ 316 stainless steel: carbon content ≤ 0.08%, containing molybdenum (2%-3%), improving the ability to resist pitting and crevice corrosion;
Difference comparison:
| Code | Corresponding materials | Carbon content | Characteristic |
|---|---|---|---|
| CF8M | 316 | ≤0.08% | Chloride corrosion resistance |
| CF3M | 316L | ≤0.03% | Low carbon, anti-intergranular corrosion |
| CF8 | 304 | ≤0.08% | General purpose stainless steel |
Physical properties
Temperature range: -196℃~650℃, suitable for extreme temperature media such as chemical industry and pharmaceutical industry; Hardness: Cast hardness HB≤187, can reach HRC22-28 after heat treatment
2. Application scenarios and standard specifications
Applicable working conditions
Corrosive media: Acidic fluids (such as hydrochloric acid, sulfuric acid dilution), chloride ion solutions (seawater treatment systems);
High-pressure valves: Comply with ASME B16.34 standards, with a maximum pressure of PN420 (such as power plant main steam valves).
Typical valve types
Gate valve: CF8M stainless steel gate valve is suitable for high-purity fluid control (such as food-grade pipelines);
Butterfly valve: Three-eccentric hard-sealed butterfly valves use CF8M valve bodies and are suitable for high-temperature steam systems;
Check valve: The vertical threaded check valve is marked with CF8M to indicate its seawater corrosion resistance.
3. Marking specifications and identification points
Casting process identification: CF series codes (such as CF8M, CF3M) refer specifically to castings, and forging codes are F series (such as F316);
Industry standards: It is necessary to combine the ASTM A351/A743 standard interpretation to ensure that the material performance meets the working conditions. Note: If the valve is marked with CF8M when selecting, it is necessary to simultaneously confirm the sealing surface treatment process (such as surfacing Stellite alloy) to improve wear resistance.
