Huahao Sealing · Carbon Graphite Components
Huahao Sealing carbon graphite grade selection guide: choose the right grade by operating temperature (-200 to 600°C), media (acid/alkali/salt/solvent), pressure (PV value), and application (mechanical seal/bushing/bearing). Covers resin-impregnated M120H, antimony M106H, carbonized M191T, copper M254J, Babbitt M254B grade comparisons.
The table below summarizes key performance parameters of Huahao Sealing's mainstream carbon graphite grades for quick comparison. All grades can be custom-machined per drawings.
| Grade | Impregnation | Density g/cm³ | Temp °C | Hardness HS | Compressive MPa | Service |
|---|---|---|---|---|---|---|
| M106H | Antimony | 1.80 | 500 | 90 | 300 | High-temp oil pumps, FCC |
| M120H | Resin | 1.78 | 220 | 85 | 260 | General chemical, aqueous |
| M191T | Carbonized | 1.85 | 600 | 95 | 350 | Extreme temp, sour media |
| M254J | Copper | 1.90 | 400 | 95 | 320 | High load, heavy duty |
| M254B | Babbitt | 1.85 | 200 | 80 | 240 | Low-speed heavy, bearings |
| M233 | Unimpregnated | 1.70 | 350 | 70 | 180 | Food-grade, low load |
Operating temperature is the primary selection factor. Exceeding the grade limit causes impregnation decomposition and oxidation failure.
≤ 200°C: M120H resin, M254B Babbitt — aqueous, oil, general chemical.
200-350°C: M233 unimpregnated, M254J copper — mid-temp oil pumps, boiler feed.
350-500°C: M106H antimony — FCC oil pumps, compressor seals, hot oil circulation.
500-600°C: M191T carbonized — FCC high-temp, sour crude, extreme service.
Below -200°C: Isostatic graphite, cryogenic grades — LNG, LOX, LN2.
Media determines impregnation type. Strong acids/alkalis need resin or carbonized; saline media needs SiC mating faces.
Strong acids (HCl, H2SO4, HNO3): M191T carbonized, strongest chemical inertness, all concentrations.
Strong alkalis (NaOH, KOH): M120H resin or M191T, 50% concentration alkali.
Salt solutions (NaCl, seawater): M254J copper + SiC mating face, chloride-ion resistance.
Organic solvents (benzene, acetone, alcohol): M120H resin, good solvent resistance.
Sour crude (H2S, sour crude): M191T carbonized, NACE MR0175 compliant.
PV value (pressure × velocity) determines mechanical load. High PV needs metal impregnation for toughness, preventing thermal cracking and spalling.
| PV MPa·m/s | Grade | Mating Face | Application |
|---|---|---|---|
| ≤ 5 | M120H resin | SS/SiC | General mechanical seals |
| 5-10 | M106H antimony | SiC | Chemical/oil pumps |
| 10-15 | M254J copper | SiC/carbide | High-load compressors |
| 15-25 | M191T carbonized | SiC | Extreme load service |
Different applications impose different requirements. Mechanical seal rings emphasize friction/wear; bushings emphasize PV load; bearings emphasize self-lubrication.
Mechanical seal rings: M106H antimony + SiC mating face, API 682 Plan 11/23/53A.
Carbon graphite bushings: M254J copper, high load, abrasive wear resistance.
Carbon graphite bearings: M254B Babbitt, low-speed heavy, self-lubricating.
Compressor seals: M106H antimony, high temp, dry running, piston rod sealing.
Agitator bearings: M120H resin, corrosive media, reactor stirring shaft.
Filter in 3 steps: ① temperature eliminates grades below limit; ② media corrosiveness eliminates incompatible; ③ PV value eliminates insufficient load. Choose remaining by price/delivery. Engineers can help with parameters.
M106H antimony (500°C) for general high-temp oil pumps. M191T carbonized (600°C, stronger chemical inertness) for extreme temp, sour, strong acid/alkali. M191T is slightly pricier but mandatory for extreme service.
SiC (silicon carbide) is the best mating face for carbon graphite seal rings — high hardness, good conductivity, corrosion resistance. Mandatory for high PV, particulate media, strong corrosion. Carbide or hardened SS for general service.
Submit your duty parameters (temperature, pressure, media, speed) — engineers reply with grade selection and quotation within 24 hours.
